explanation blue bibcodes open ADS page with paths to full text
Author name code: kucera-ales
ADS astronomy entries on 2022-09-14
author:"Kucera, Ales"
---------------------------------------------------------
Title: The Solar Activity Monitor Network - SAMNet
Authors: Erdélyi, Robertus; Korsós, Marianna B.; Huang, Xin; Yang,
Yong; Pizzey, Danielle; Wrathmall, Steven A.; Hughes, Ifan G.;
Dyer, Martin J.; Dhillon, Vikram S.; Belucz, Bernadett; Brajša,
Roman; Chatterjee, Piyali; Cheng, Xuewu; Deng, Yuanyong; Domínguez,
Santiago Vargas; Joya, Raúl; Gömöry, Peter; Gyenge, Norbert G.;
Hanslmeier, Arnold; Kucera, Ales; Kuridze, David; Li, Faquan; Liu,
Zhong; Xu, Long; Mathioudakis, Mihalis; Matthews, Sarah; McAteer,
James R. T.; Pevtsov, Alexei A.; Pötzi, Werner; Romano, Paolo; Shen,
Jinhua; Temesváry, János; Tlatov, Andrey G.; Triana, Charles; Utz,
Dominik; Veronig, Astrid M.; Wang, Yuming; Yan, Yihua; Zaqarashvili,
Teimuraz; Zuccarello, Francesca
2022JSWSC..12....2E Altcode:
The Solar Activity Magnetic Monitor (SAMM) Network (SAMNet) is a
future UK-led international network of ground-based solar telescope
stations. SAMNet, at its full capacity, will continuously monitor
the Sun's intensity, magnetic, and Doppler velocity fields at
multiple heights in the solar atmosphere (from photosphere to upper
chromosphere). Each SAMM sentinel will be equipped with a cluster of
identical telescopes each with a different magneto-optical filter (MOFs)
to take observations in K I, Na D, and Ca I spectral bands. A subset
of SAMM stations will have white-light coronagraphs and emission line
coronal spectropolarimeters. The objectives of SAMNet are to provide
observational data for space weather research and forecast. The goal
is to achieve an operationally sufficient lead time of e.g., flare
warning of 2-8 h and provide many sought-after continuous synoptic
maps (e.g., LoS magnetic and velocity fields, intensity) of the lower
solar atmosphere with a spatial resolution limited only by seeing or
diffraction limit, and with a cadence of 10 min. The individual SAMM
sentinels will be connected to their master HQ hub where data received
from all the slave stations will be automatically processed and flare
warning issued up to 26 h in advance.
---------------------------------------------------------
Title: Spectropolarimetric Observations of an Arch Filament System
with GREGOR
Authors: Balthasar, H.; Gömöry, P.; González Manrique, S. J.;
Kuckein, C.; Kučera, A.; Schwartz, P.; Berkefeld, T.; Collados, M.;
Denker, C.; Feller, A.; Hofmann, A.; Schlichenmaier, R.; Schmidt,
D.; Schmidt, W.; Sigwarth, M.; Sobotka, M.; Solanki, S. K.; Soltau,
D.; Staude, J.; Strassmeier, K. G.; von der Lühe, O.
2019ASPC..526..217B Altcode: 2018arXiv180401789B
We observed an arch filament system (AFS) in a sunspot group with the
GREGOR Infrared Spectrograph attached to the GREGOR solar telescope. The
AFS was located between the leading sunspot of negative polarity and
several pores of positive polarity forming the following part of the
sunspot group. We recorded five spectro-polarimetric scans of this
region. The spectral range included the spectral lines Si I 1082.7
nm, He I 1083.0 nm, and Ca I 1083.9 nm. In this work we concentrate
on the silicon line which is formed in the upper photosphere. The
line profiles are inverted with the code 'Stokes Inversion based
on Response functions' to obtain the magnetic field vector. The
line-of-sight velocities are determined independently with a Fourier
phase method. Maximum velocities are found close to the ends of AFS
fibrils. These maximum values amount to 2.4 km s<SUP>-1</SUP> next
to the pores and to 4 km s<SUP>-1</SUP> at the sunspot side. Between
the following pores, we encounter an area of negative polarity that
is decreasing during the five scans. We interpret this by new emerging
positive flux in this area canceling out the negative flux. In summary,
our findings confirm the scenario that rising magnetic flux tubes
cause the AFS.
---------------------------------------------------------
Title: Flare-induced changes of the photospheric magnetic field in
a δ-spot deduced from ground-based observations
Authors: Gömöry, P.; Balthasar, H.; Kuckein, C.; Koza, J.;
Veronig, A. M.; González Manrique, S. J.; Kučera, A.; Schwartz,
P.; Hanslmeier, A.
2017A&A...602A..60G Altcode: 2017arXiv170406089G
<BR /> Aims: Changes of the magnetic field and the line-of-sight
velocities in the photosphere are being reported for an M-class
flare that originated at a δ-spot belonging to active region NOAA
11865. <BR /> Methods: High-resolution ground-based near-infrared
spectropolarimetric observations were acquired simultaneously in
two photospheric spectral lines, Fe I 10783 Å and Si I 10786 Å,
with the Tenerife Infrared Polarimeter at the Vacuum Tower Telescope
(VTT) in Tenerife on 2013 October 15. The observations covered several
stages of the M-class flare. Inversions of the full-Stokes vector of
both lines were carried out and the results were put into context using
(extreme)-ultraviolet filtergrams from the Solar Dynamics Observatory
(SDO). <BR /> Results: The active region showed high flaring activity
during the whole observing period. After the M-class flare, the
longitudinal magnetic field did not show significant changes along
the polarity inversion line (PIL). However, an enhancement of the
transverse magnetic field of approximately 550 G was found that
bridges the PIL and connects umbrae of opposite polarities in the
δ-spot. At the same time, a newly formed system of loops appeared
co-spatially in the corona as seen in 171 Å filtergrams of the
Atmospheric Imaging Assembly (AIA) on board SDO. However, we cannot
exclude that the magnetic connection between the umbrae already existed
in the upper atmosphere before the M-class flare and became visible
only later when it was filled with hot plasma. The photospheric
Doppler velocities show a persistent upflow pattern along the PIL
without significant changes due to the flare. <BR /> Conclusions:
The increase of the transverse component of the magnetic field after
the flare together with the newly formed loop system in the corona
support recent predictions of flare models and flare observations. <P
/>The movie associated to Figs. 4 and 5 is available at <A
href="http://www.aanda.org/10.1051/0004-6361/201730644/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: Propagation of filament and hot plasma through solar atmosphere
as observed with ground based and space instruments
Authors: Kucera, A.
2017psio.confE..73K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: NLTE modeling of a small active region filament observed with
the VTT
Authors: Schwartz, P.; Balthasar, H.; Kuckein, C.; Koza, J.; Gömöry,
P.; Rybák, J.; Heinzel, P.; Kučera, A.
2016AN....337.1045S Altcode:
An active region mini-discretionary-filament was observed with the
Vacuum Tower Telescope (VTT) in Tenerife simultaneously in the He
I infrared triplet using the Tenerife Infrared Polarimeter 1 (TIP
1), in Hα with the TESOS Fabry-Pérot interferometer, and in Ca II
8542 Å with the VTT spectrograph. The spectropolarimetric data were
inverted using the HAZEL code and Hα profiles were modelled by solving
a NLTE radiative transfer in a simple isobaric and isothermal 2D slab
irradiated both from its bottom and sides from the solar surface. It was
found that the mini-discretionary-filament is composed of horizontal
fluxtubes, along which the cool plasma of T∼10 000 K can flow with
very large, even supersonic, velocities.
---------------------------------------------------------
Title: Spectropolarimetric observations of an arch filament system
with the GREGOR solar telescope
Authors: Balthasar, H.; Gömöry, P.; González Manrique, S. J.;
Kuckein, C.; Kavka, J.; Kučera, A.; Schwartz, P.; Vašková, R.;
Berkefeld, T.; Collados Vera, M.; Denker, C.; Feller, A.; Hofmann,
A.; Lagg, A.; Nicklas, H.; Orozco Suárez, D.; Pastor Yabar, A.;
Rezaei, R.; Schlichenmaier, R.; Schmidt, D.; Schmidt, W.; Sigwarth,
M.; Sobotka, M.; Solanki, S. K.; Soltau, D.; Staude, J.; Strassmeier,
K. G.; Volkmer, R.; von der Lühe, O.; Waldmann, T.
2016AN....337.1050B Altcode: 2016arXiv160901514B
Arch filament systems occur in active sunspot groups, where a fibril
structure connects areas of opposite magnetic polarity, in contrast to
active region filaments that follow the polarity inversion line. We
used the GREGOR Infrared Spectrograph (GRIS) to obtain the full
Stokes vector in the spectral lines Si I λ1082.7 nm, He I λ1083.0
nm, and Ca I λ1083.9 nm. We focus on the near-infrared calcium line
to investigate the photospheric magnetic field and velocities, and
use the line core intensities and velocities of the helium line to
study the chromospheric plasma. The individual fibrils of the arch
filament system connect the sunspot with patches of magnetic polarity
opposite to that of the spot. These patches do not necessarily coincide
with pores, where the magnetic field is strongest. Instead, areas are
preferred not far from the polarity inversion line. These areas exhibit
photospheric downflows of moderate velocity, but significantly higher
downflows of up to 30 km s<SUP>-1</SUP> in the chromospheric helium
line. Our findings can be explained with new emerging flux where the
matter flows downward along the field lines of rising flux tubes,
in agreement with earlier results.
---------------------------------------------------------
Title: Non-LTE Inversion of Spectropolarimetric and Spectroscopic
Observations of a Small Active-region Filament Observed at the VTT
Authors: Schwartz, P.; Balthasar, H.; Kuckein, C.; Koza, J.; Gömöry,
P.; Rybák, J.; Kučera, A.; Heinzel, P.
2016ASPC..504..205S Altcode:
An active region mini-filament was observed by VTT simultaneously
in the He<small>I</small> 10 830 Å triplet by the TIP 1
spectropolarimeter, in Hα by the TESOS Fabry-Pérot interferometer, and
in Ca <small>II</small> 8542 Å by the VTT spectrograph. The
spectropolarimetric data were inverted using the HAZEL code and Hα
profiles were modelled solving a NLTE radiative transfer in a simple
isobaric and isothermal 2D slab irradiated both from bottom and
sides. It was found that the mini-filament is composed of horizontal
fluxtubes, along which the cool plasma of T∼10 000 K can flow by
very large - even supersonic - velocities.
---------------------------------------------------------
Title: The CoMP-S Instrument at the Lomnický Peak Observatory:
Status Report
Authors: Kučera, A.; Ambróz, J.; Gömöry, P.; Habaj, P.; Kavka,
J.; Kozák, M.; Schwartz, P.; Rybák, J.; Tomczyk, S.; Sewell, S.;
Aumiller, P.; Summers, R.; Watt, A.
2016ASPC..504..321K Altcode:
The Coronal Multi-channel Polarimeter for Slovakia (CoMP-S) has
been installed at the high-altitude Lomnicky Peak Observatory of the
Astronomical Institute of SAS (2633 m a.s.l.) in 2011. The instrument
was designed and manufactured by HAO/NCAR (Boulder, USA) with a
tunable Lyot filter and polarimeter for visible and near IR spectral
regions. This instrument is proposed for coronagraphic observations of
magnetic and velocity fields in the solar corona and in prominences. A
fundamental upgrade of this instrument has been prepared with pair
of cameras sensitive in the near IR spectral region in a new camera
module. This upgrade is being incorporated to the instrument in course
of the year 2014. In this contribution the technical parameters of the
final configuration of the CoMP-S instrument containing four cameras,
covering both visible and near IR spectral regions, are described. We
also present a potential of the CoMP-S instrument for coronagraphic
spectro-polarimetric observations of the solar corona and prominences
with a capability for sequential measurements of the spectral profiles
of all prominent emission lines in spectral region from 500 to 1100 nm.
---------------------------------------------------------
Title: Dual instrument for Flare and CME onset observations -
Double solar Coronagraph with Solar Chromospheric Detector and
Coronal Multi-channel Polarimeter at Lomnicky stit Observatory
Authors: Kucera, Ales; Tomczyk, Steven; Rybak, Jan; Sewell, Scott;
Gomory, Peter; Schwartz, Pavol; Ambroz, Jaroslav; Kozak, Matus
2015IAUGA..2246687K Altcode:
We report on unique dual instrument developed for simultaneous
measurements of velocity and magnetic fields in the solar chromosphere
and corona. We describe the technical parameters and capability of
the Coronal Multi-channel Polarimeter (CoMP-S) and Solar Chromospheric
detector (SCD) mounted at the Double solar coronagraph at Lomnicky Stit
Observatory and working simultaneously with strictly parallel pointing
of both coronagraphs. The CoMP-S is 2D spectropolarimeter designed
for observations of VIS and near-IR emission lines of prominences
and corona with operating spectral range: 500 - 1100 nm, sequential
measurement of several VIS and near-IR lines. Its field of view is
14 arcmin x 11 arcmin. It consists of 4-stage calcite Lyot filter
followed by the ferro-liquid crystal polarizer and four cameras (2
visible, 2 infrared). The capability is to deliver 2D full Stokes I,
Q, U, V, using registration with 2 IR cameras (line + background) and
2 VIS cameras (line + background) SCD is a single beam instrument to
observe bright chromosphere. It is a combination of tunable filter and
polarimeter. Spectral resolution of the SCD ranges from 0.046 nm for
observations of the HeI 1083 nm line up to to 25 pm is for observation
of the HeI 587.6 nm line. The birefringent filter of the SCD has high
spectral resolution, as well as spatial resolution (1.7 arcseconds)
and temporal resolution (10 seconds) First results are also reported
and discussed.
---------------------------------------------------------
Title: The Košice meteorite fall: Recovery and strewn field
Authors: Tóth, Juraj; Svoreň, Ján; BorovičKa, Jiří Spurný,
Pavel; Igaz, Antal; Kornoš, Leonard; Vereš, Peter; Husárik,
Marek; Koza, Július; Kučera, Aleš Zigo, Pavel; Gajdoš, Štefan;
Világi, Jozef; Čapek, David; Krišandová, Zuzana; Tomko, Šdušan;
Ilha, Jiří Schunová, Eva; Bodnárová, Marcela; Búzová, Diana;
Krejčová, Tereza
2015M&PS...50..853T Altcode: 2015M&PS..tmp..174T
We provide the circumstances and details of the fireball observation,
search expeditions, recovery, strewn field, and physical characteristics
of the Košice meteorite that fell in Slovakia on February 28,
2010. The meteorite was only the 15th case of an observed bolide with
a recovered mass and subsequent orbit determination. Despite multiple
eyewitness reports of the bolide, only three videos from security
cameras in Hungary were used for the strewn field determination and
orbit computation. Multiple expeditions of professionals and individual
searchers found 218 fragments with total weight of 11.3 kg. The strewn
field with the size of 5 × 3 km is characterized with respect to the
space distribution of the fragments, their mass and size-frequency
distribution. This work describes a catalog of 78 fragments, mass,
size, volume, fusion crust, names of discoverers, geographic location,
and time of discovery, which represents the most complex study of a
fresh meteorite fall. From the analytical results, we classified the
Košice meteorite as an ordinary H5 chondrite.
---------------------------------------------------------
Title: Inferring spectral characteristics of the Hα spectral line
observed by the DOT Lyot filter
Authors: Koza, J.; Rybák, J.; Gömöry, P.; Kučera, A.
2014CoSka..44...43K Altcode:
A tunable Lyot filter can serve as a spectroscopic device rendering
wide-field 2-D pseudospectroscopy of solar structures and follow-up
crude reconstruction of a spectral line profile at each pixel within the
field of view. We developed a method of inferring of the Doppler shift,
the core intensity, the core width, and the core asymmetry of the Hα
spectral line observed by the Lyot filter installed on the Dutch Open
Telescope (DOT). The spectral characteristics are inferred through the
fitting of five intensity samples, separated from each other by 0.35 Å,
by a 4<SUP>th</SUP>-order polynomial, a Gaussian, and a parabola. We
use the atlas Hα profile as a reference in estimating deviations
of the derived spectral characteristics. The Gaussian is the most
preferable means for measurements of the Doppler shift with deviations
smaller than 1 km s<SUP>-1</SUP>. When using the 4<SUP>th</SUP>-order
polynomial, deviations are within the interval ±2.5 km s<SUP>-1</SUP>,
but it renders comparable deviations of the core intensity and the
width as the Gaussian. The deviations are largely insensitive to the
shape of the filter transmission, but depend mostly non-linearly on
the Doppler shift. Therefore, they do not cancel out if the spectral
characteristics are represented by their relative variations. Results
can be used as corrections of spectral characteristics extracted from
area-averaged Hα profiles acquired by the DOT Lyot filter.
---------------------------------------------------------
Title: Transmission profile of the Dutch Open Telescope Hα Lyot
filter
Authors: Koza, J.; Hammerschlag, R. H.; Rybák, J.; Gömöry, P.;
Kučera, A.; Schwartz, P.
2014AN....335..409K Altcode: 2017arXiv171209253K
Context Accurate knowledge of the spectral transmission profile of
a Lyot filter is important, in particular in comparing observations
with simulated data. The paper summarizes available facts about the
transmission profile of the Dutch Open Telescope (DOT) Hα Lyot filter
pointing to a discrepancy between sidelobe-free Gaussian-like profile
measured spectroscopically and signatures of possible leakage of
parasitic continuum light in DOT Hα images. We compute wing-to-center
intensity ratios resulting from convolutions of Gaussian and square
of the sinc function with the Hα atlas profile and compare them with
the ratios derived from observations of the quiet Sun chromosphere at
disk center. We interpret discrepancies between the anticipated and
observed ratios and the sharp limb visible in the DOT Hα image as an
indication of possible leakage of parasitic continuum light. A method
suggested here can be applied also to indirect testing of transmission
profiles of other Lyot filters. We suggest two theoretical transmission
profiles of the DOT Hα Lyot filter which should be considered as the
best available approximations. Conclusive answer can only be given by
spectroscopic re-measurement of the filter.
---------------------------------------------------------
Title: Coronal Multi-channel Polarimeter at the Lomnicky Peak
Observatory
Authors: Schwartz, P.; Ambroz, J.; Gömöry, P.; Kozák, M.; Kučera,
A.; Rybák, J.; Tomczyk, S.; Sewell, S.; Aumiller, P.; Summers, R.;
Sutherland, L.; Watt, A.
2014IAUS..300..521S Altcode:
Coronal Multi-channel Polarimeter (CoMP-S), developed by HAO/NCAR, has
been introduced to regular operation at the Lomnicky Peak Observatory
(High Tatras in northern Slovakia, 2633 m a.s.l.) of the Astronomical
Institute of Slovak Academy of Sciences. We present here the technical
parameters of the current version of the instrument and its potential
for observations of prominences in the visual and near-IR spectral
regions. The first results derived from observations of prominences
in the Hα emission line taken during a coordinated observing campaign
of several instruments in October 2012 are shown here.
---------------------------------------------------------
Title: Search for Alfvén waves in a bright network element observed
in Hα
Authors: Koza, J.; Sütterlin, P.; Gömöry, P.; Rybák, J.;
Kučera, A.
2013CoSka..43....5K Altcode: 2013arXiv1304.4027K
Alfvén waves are considered as potential transporters of energy
heating the solar corona. We seek spectroscopic signatures of the
Alfvén waves in the chromosphere occupied by a bright network element,
investigating temporal variations of the spectral width, intensity,
Dopplershift, and the asymmetry of the core of the Hα spectral
line observed by the tunable Lyot filter installed on the Dutch Open
Telescope. The spectral characteristics are derived through the fitting
of five intensity samples, separated from each other by 0.35 Å, by a
4<SUP>th</SUP>-order polynomial. The bright network element displays
the most pronounced variations of the Dopplershift varying from 0 to 4
km s<SUP>-1</SUP> about the average of 1.5 km s<SUP>-1</SUP>. This fact
implies a persistent redshift of the Hα core with a redward asymmetry
of about 0.5 km s<SUP>-1</SUP>, suggesting an inverse-C bisector. The
variations of the core intensity up to ±10 % and the core width up to
±5 % about the respective averages are much less pronounced, but still
detectable. The core intensity variations lag behind the Dopplershift
variations about 2.1 min. The Hα core width tends to correlate with
the Dopplershift and anticorrelate with the asymmetry, suggesting that
more redshifted Hα profiles are wider and the broadening of the Hα
core is accompanied with a change of the core asymmetry from redward
to blueward. We also found a striking anticorrelation between the
core asymmetry and the Dopplershift, suggesting a change of the core
asymmetry from redward to blueward with an increasing redshift of the
Hα core. The data and the applied analysis do not show meaningful
tracks of Alfvén waves in the selected network element.
---------------------------------------------------------
Title: A quiescent prominence observed in the Hα line by the COMP-S
instrument at the Lomnický Peak Observatory
Authors: Schwartz, P.; Rybák, J.; Kučera, A.; Kozák, M.; Ambróz,
J.; Gömöry, P.
2012CoSka..42..135S Altcode:
A prominence above the NEE limb was observed by the COMP-S instrument
attached to the ZEISS coronagraph located at the Lomnický Peak
Observatory. Observations were carried out on Nov 2, 2011 between
14:01:13 and 14:11:34 UT. The filter of the instrument was tuned during
measurements sequentially in five wavelengths within the profile of
the Hα line: 0, ±1, ±2 Å around 6563 Å. FWHM of the transmission
function of the filter was ∼0.4Å at these wavelengths. Data were
not absolutely calibrated, therefore they could be fitted using only a
simple cloud model (1D geometry, a complete frequency redistribution,
a source function independent of the optical depth) to diagnose the
prominence plasma. As five wavelength points in the profile were not
enough for an automatic fitting, five positions at the prominence were
chosen for the analysis. Observed data from the five positions were
simulated using the cloud model and groups of different models were
found for each position. It means that the wavelength scale of a step
as large as 1 Å when used for the Hα line is not fine enough for
estimation of a correct and unique model. Simulating observations
using three different finer wavelength scales it was found that
the wavelength scale with a step of 0.3 Å and even more finer in
the line core (step of 0.1 Å) is already suitable for more precise
and unambiguous plasma diagnostics. We also show that for correct
plasma diagnostics it is crucial to take into account an effect of a
finite width of the transmission function of the filter. If observed
data were fitted irrespectively of this important effect, an error
in estimated model parameters could exceed even 100 %, except for
the Doppler velocities, for which the error would be much smaller,
e.g. for velocities up to 20 km s<SUP>-1</SUP> the error is below 1 %.
---------------------------------------------------------
Title: Košice meteorite - recovery and the strew field
Authors: Toth, J.; Porubčan, V.; Borovička, J.; Igaz, A.; Spurný,
P.; Svoreň, J.; Husárik, M.; Kornoš, L.; Vereš, P.; Zigo, P.;
Koza, J.; Kučera, A.; Gajdoš, S.; Világi, J.; Čapek, D.; Šilha,
J.; Schunová, E.; Krišandová, Z.; Tomko, D.; Bodnárová, M.;
Búzová, D.; Krejčová, T.
2012epsc.conf..708T Altcode: 2012espc.conf..708T
The glare of the bolide on the night of February 28, 2010,
illuminated streets and interior of apartments, at some places in
Eastern Slovakia and Northern Hungary and cannon-like burst or series
of low frequency blasts were heard. Due to bad weather, cloudy skies
and scatter showers the Central European Fireball Network (operated
by Pavel Spurný of the Czech Academy of Sciences) did not take direct
optical records of the bolide and also the Slovak Video Meteor Network
(operated by Juraj Tóth of Comenius University in Bratislava) did
not operate that night so that at first moment it seemed that there
were no scientific records available of this event. Fortunately, fast
photoelectric sensors on 7 automated fireball stations in the Czech
Republic (6) and Austria (1) worked also under cloudy sky and recorded
the light curve of the bolide. It enabled to determine the exact time
and duration of the event and to estimate its brightness as well. The
bolide reached the maximum brightness of at least -18 magnitudes in one
huge flare. This light curve was used also for modeling of meteoroid
atmospheric fragmentation. Later, several surveillance cameras data
were published showing the moment when the night became a day. Three
videos from Hungary (Örkény village, Fazzi Daniella and Vass Gábor;
Telki village, contact persons Sárneczky Krisztián, Kiss László and
Budapest) actually captured the fireball itself. Thanks to calibration
of videos by several members of the Hungarian Astronomical Association
(MCSE - www.mcse.hu, namely by Igaz Antal) and the trajectory analysis
done by Jiří Borovička gave the hope that significant number
of meteorite fragments reached the surface. He also calculated the
impact area western of the city of Košice in Eastern Slovakia. The
data from the Local Seismic Network of Eastern Slovakia (Peter Moczo
of the Comenius University) analyzed by Pavel Kalenda confirmed the
atmospheric trajectory as well [1].
---------------------------------------------------------
Title: The LSO/KSO Hα prominence catalogue: cross-calibration of data
Authors: Rybák, J.; Gömöry, P.; Mačura, R.; Kučera, A.; Rušin,
V.; Pötzi, W.; Baumgartner, D.; Hanslmeier, A.; Veronig, A.;
Temmer, M.
2011CoSka..41..133R Altcode:
We present work on the extension of the homogeneous prominence
catalogue created for the epoch 1967 — 2009 at the Lomnicky Peak
Observatory (LSO) by incorporating new data acquired at the Kanzelhöhe
Observatory for Solar and Environmental Research (KSO). We use data of
20 Hα prominences observed almost simultaneously at both observatories
during four days in August/September 2009 to analyze the significance
of differences of the determined parameters used in the Hα prominence
catalogue. A reduction of the data from KSO and adaptation of the
resulting parameters to fit the parameters of the LSO catalogue confirm
that no special homogenization is needed to create a common catalogue
data set. Thus, we justified that the LSO catalogue could be extended
onward in the future using a more comprehensive database of observations
from KSO.
---------------------------------------------------------
Title: Koronálny multikanálový polarimeter pre observatórium
Lomnický štít
---------------------------------------------------------
Title: Koronálny multikanálový polarimeter
pre observatórium Lomnický štít
---------------------------------------------------------
Title: Coronal multichannel
polarimeter for Lomnický štít Observatory.
Authors: Rybák, J.; Ambróz, J.; Gömöry, P.; Kozák, M.; Kučera,
A.; Tomczyk, S.; Sewell, S.; Summers, R.; Sutherland, L.; Watt, A.
2010nspm.conf..196R Altcode:
The contribution presents the process of development and preparation
of the Coronal Multi-channel Polarimeter (COMP-S) for the Lomnický
štít Observatory of the SAS Astronomy Institute. The design of the
device is based on the experience gained in recent years with the CoMP
(High Altitude Observatory / NCAR; Boulder, USA) instrument. The device
will be a combination of two main optical components: the Lyot tunable
filter and polarimeter, and is prepared specifically for one of the
20 cm Zeiss coronagraph at the Lomnický štít Observatory where it
will be installed in 2011. CoMP-S will differ from its predecessor
in several respects. The most important difference is that CoMP-S
will be able to observe the corona and chromospheric emission lines
in the wavelength range from 530 to 1083 nm. This feature will be
achieved using superachromatic wave plates and dichroic polarizers
with wide bandwidth. Furthermore, in the CoMP-S instrument new SWIFT
liquid crystals of Meadowlark Optics company will be used as variable
retarders instead of nematic liquid crystal retarders (LCVR) which
will considerably shorten the measuring process. Ferroelectric liquid
crystals will provide measurements of the full Stokes vector with nearly
optimal polarization throughout the whole instrument bandwidth. Recently
developed sCMOS cameras are to provide diffraction limit resolution of
observations, with the 860x680 arc second field and 30-frames-per-second
cadence. The device will be used in the Astronomical Observatory of SAS
at Lomnický štít primarily for spectrum polarimetry of prominences
and coronal loops of the active solar regions.
---------------------------------------------------------
Title: Magnetic loop emergence within a granule
Authors: Gömöry, P.; Beck, C.; Balthasar, H.; Rybák, J.; Kučera,
A.; Koza, J.; Wöhl, H.
2010A&A...511A..14G Altcode: 2009arXiv0910.4449G
<BR /> Aims: We investigate the temporal evolution of magnetic
flux emerging within a granule in the quiet-Sun internetwork at
disk center. <BR /> Methods: We combined IR spectropolarimetry of
high angular resolution performed in two Fe i lines at 1565 nm with
speckle-reconstructed G-band imaging. We determined the magnetic
field parameters by a LTE inversion of the full Stokes vector using
the SIR code, and followed their evolution in time. To interpret
the observations, we created a geometrical model of a rising loop in
3D. The relevant parameters of the loop were matched to the observations
where possible. We then synthesized spectra from the 3D model for a
comparison to the observations. <BR /> Results: We found signatures of
magnetic flux emergence within a growing granule. In the early phases,
a horizontal magnetic field with a distinct linear polarization signal
dominated the emerging flux. Later on, two patches of opposite circular
polarization signal appeared symmetrically on either side of the linear
polarization patch, indicating a small loop-like structure. The mean
magnetic flux density of this loop was roughly 450 G, with a total
magnetic flux of around 3 × 10<SUP>17</SUP> Mx. During the ~12 min
episode of loop occurrence, the spatial extent of the loop increased
from about 1 to 2 arcsec. The middle part of the appearing feature
was blueshifted during its occurrence, supporting the scenario of an
emerging loop. There is also clear evidence for the interaction of
one loop footpoint with a preexisting magnetic structure of opposite
polarity. The temporal evolution of the observed spectra is reproduced
to first order by the spectra derived from the geometrical model. During
the phase of clearest visibility of the loop in the observations,
the observed and synthetic spectra match quantitatively. <BR />
Conclusions: The observed event can be explained as a case of flux
emergence in the shape of a small-scale loop. The fast disappearance
of the loop at the end could possibly be due to magnetic reconnection.
---------------------------------------------------------
Title: Analyses of magnetic field structures for active region 10720
using a data-driven 3D MHD model
Authors: Wu, S. T.; Wang, A. H.; Gary, G. Allen; Kucera, Ales; Rybak,
Jan; Liu, Yang; Vrśnak, Bojan; Yurchyshyn, Vasyl
2009AdSpR..44...46W Altcode:
In order to understand solar eruptive events (flares and CMEs) we
need to investigate the changes at the solar surface. Thus, we use
a data-driven, three-dimensional magnetohydrodynamic (MHD) model to
analyze a flare and coronal mass ejection productive active region,
AR 10720 on January 15, 2005. The measured magnetic field from Big
Bear Solar Observatory (BBSO) digital vector magnetograph (DGVM) was
used to model the non-potential coronal magnetic field changes and the
evolution of electric current before and after the event occurred. The
numerical results include the change of magnetic flux ( Φ), the net
electric current ( I<SUB>N</SUB>), the length of magnetic shear of the
main neutral line ( L<SUB>ss</SUB>), the flux normalized measure of
the field twist (α={μI<SUB>N</SUB>}/{Φ}) with μ being the magnetic
permeability. The current helicity ( H<SUB>c</SUB>) injected into the
corona and the photospheric surface velocity are also computed. The
characteristic parameters of the buildup process before the event and
the decay process after the event are investigated and the amount of
magnetic energy converted to drive the event is estimated.
---------------------------------------------------------
Title: Solar Convection and Oscillation Interaction
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.;
Gömöry, P.
2009CEAB...33...51H Altcode:
In this paper we investigate bisectors of solar photospheric lines. The
bisectors reflect vertical velocity gradients over the height of line
formation and therefore reveal important information about the dynamics
in these layers. Their shape and shift is influenced by (a) convective
motions, (b) oscillatory motions that can act differently at different
photospheric heights. The bisectors are selected from different
locations that show mainly a granular evolution or an intergranular
evolution. Two selection criteria were applied: continuum intensity
(enhanced for granular bisectors, reduced for intergranular bisectors),
and full width at half maximum values (enhanced for intergranular
bisectors). The results demonstrate how oscillatory motions influence
the bisectors as a whole. In the example given a smaller amplitude of
oscillations over intergranular areas is indicated.
---------------------------------------------------------
Title: Observational Evidence for Shocks in the Solar Photosphere -
New TESOS/VTT Results
Authors: Rybak, J.; Kucera, A.; Hanslmeier, A.; Woehl, H.;
Wedemeyer-Boehm, S.; Steiner, O.
2008ESPM...12.2.36R Altcode:
High-resolution spectroscopic observations recently acquired with the
TESOS spectrometer at the Vacuum Tower Telescope (VTT, Observatorio
del Teide, Tenerife) are used to test predictions regarding strongly
dynamic events in the photosphere as obtained from three-dimensional
numerical simulations with the CO5BOLD-code. <P />Time series of
two-dimensional maps of the Fe I 543.4 nm spectral line profile at
different centre-to-limb positions are investigated in a statistical
sense by comparing the distributions of individual spectral parameters
derived from observations with the corresponding distributions
from synthesized spectra calculated with the LINFOR3D code from
the simulations. Appropriate degradation of the synthesized spectra
was applied in order to take the limited spatial resolution of the
telescope, seeing effects, and the scattered instrumental light into
account. <P />At the actual spatial resolution of 0.5 arc sec, the
statistics show that signatures of the photospheric dynamics, including
the most dynamical events like occasional supersonic flows of plasma in
the nearly horizontal direction, are very similar in both observations
and simulations. <P />Discrepancies are found only for those spectral
parameters (residual line intensity, Doppler line core shifts), which
are affected by non-LTE effects, since non-LTE effects are not taken
into account in the synthesis of the Fe I 543.4nm spectral line.
---------------------------------------------------------
Title: Multi-wavelength Observations of Dynamic Fibrils in the Upper
Photosphere and Chromosphere
Authors: Kucera, A.; Beck, Ch.; Gomory, P.; Koza, J.; Woehl, H.;
Rybak, J.
2008ESPM...12.2.52K Altcode:
Spatial and temporal evolution of dynamic fibrils (DF) as well as
coupling with photospheric features was investigated. <P />The
main target were remnants in the active region 10997 on May 28,
2008. We used about 1 hour series of multi wavelength simultaneous
observations of the DFs and corresponding photospheric features. The
observations were performed with the german Vacuum Tower Telescope
equipped with several post-focus instruments. Namely: TESOS (Triple
Etalon SOlar Spectrometer) instrument was used in polarimetric mode
(VIP=Visual Imaging Polarimeter) to register 2D spectra of the DFs in
H-alpha line and in magnetically sensitive Fe I 630.2 nm line. TIP
(Tenerife Infrared Polarimeter) mounted on the Echelle spectrograph
was used for spectropolarimetric observations of two neutral iron
lines at 1.56 micrometers. We scanned 2D area 80" x 5", producing
thus 2D maps of intensity, velocity and magnetic field of the low
photosphere under the chromospheric fibril field. <P />Additionally
G-band and H-alpha images were registered with high cadence and
the supporting data from the TRACE satellite (17.1 nm, WL, Lyman
alpha line and 160 nm continuum) are also available. After careful
spatial coalignment of 2D maps we first selected numerous DFs in the
H-alpha images. Then we investigated temporal evolution of those DFs
concerning changes of their dimensions, positions and fluctuations
and correlated these characteristics with temporal evolution of the
intensities, velocities and magnetic field characteristics observed in
the spatially corresponding photosphere. The poster demonstrates the
complex observations, data reduction and coalignment and preliminary
results on coupling between DFs and underlying photospheric features.
---------------------------------------------------------
Title: Observation of Turbulence in Solar Surface Convection:
I. Line Parameter Correlations
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
2008SoPh..249..293H Altcode: 2008SoPh..tmp...88H
By using slit observations of solar photospheric lines shifted by 0.4
arcsec, a 2D field on the Sun was scanned to obtain a 16-minute time
series of 2D line-parameter variations. The aim was to investigate in
detail the occurrence of turbulence that can be measured by line-width
variations extracted from the line profiles. The continuum-intensity
variation served as a proxy for granular (bright) and intergranular
(dark) areas. The results show that turbulence is not limited to
the intergranular space but is also produced by horizontal motions
that may become supersonic, leading to turbulence. These motions
lead to brightenings, as predicted by theoretical models. Thus,
enhanced line-width variations are found to occur in both bright and
dark areas. A Sobel filter served to detect the areas where strong
gradients in the line parameters occur. By applying this filter to the
different line-parameter variations over the 2D field observed, we can
determine whether there exists a similarity of these strong-gradient
patterns with other parameters that characterize granular motions such
as intensity variations or velocity fluctuations.
---------------------------------------------------------
Title: Temporal Variations in Fibril Orientation
Authors: Koza, J.; Sütterlin, P.; Kučera, A.; Rybák, J.
2007ASPC..368..115K Altcode: 2007astro.ph..3733K
We measure variations in orientation of fourteen dynamic fibrils as
a function of time in a small isolated plage and nearby network using
a 10-min time sequence of Hα filtergrams obtained by the Dutch Open
Telescope. We found motions with average angular velocities of the
order of 1 deg min<SUP>-1</SUP> suggesting systematic turning from
one limit position to another, particularly apparent in the case of
fibrils with lifetimes of a few minutes. Shorter fibrils tend to turn
faster than longer ones, which we interpret as due to vortex flows in
the underlying granulation that twist magnetic fields.
---------------------------------------------------------
Title: Propagating Waves in the Chromospheric Network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2007ASPC..368..133G Altcode:
Wave modulation of ultraviolet emissions originated in and above quiet
chromospheric network is studied. In particular, cross-correlation,
wavelet analysis and phase difference analysis of the intensities
as well as the Doppler shifts of emission lines of He I 584.33 Å
(chromosphere), O V 629.73 Å (transition region) and Mg IX 368.07 Å
(corona) are employed to study waves at different heights and their
direction of propagation. The results are interpreted as evidence of
compressive waves that propagate downward from the transition region
to the chromosphere in the observed chromospheric network. Different
scenarios regarding the origin and source localization of these waves
are discussed.
---------------------------------------------------------
Title: The height dependence of temperature velocity correlation in
the solar photosphere
Authors: Koza, J.; Kučera, A.; Rybák, J.; Wöhl, H.
2007msfa.conf..139K Altcode: 2007arXiv0704.0603K
We derive correlation coefficients between temperature and line-of-sight
velocity as a function of optical depth throughout the solar photosphere
for the non-magnetic photosphere and a small area of enhanced magnetic
activity. The maximum anticorrelation of about -0.6 between temperature
and line-of-sight velocity in the non-magnetic photosphere occurs at
log [tau] 5 = -0.4. The magnetic field is another decorrelating factor
along with 5-min oscillations and seeing.
---------------------------------------------------------
Title: Spectral Characteristics of the Photosphere near a Flare
Authors: Kučera, A.; Wöhl, H.; Rybák, J.; Wu, S. T.; Wang, A. H.
2007CEAB...31...21K Altcode:
We present the temporal evolution of dynamical characteristics of the
solar photosphere in an active region near a flare. Namely, spatial
and temporal variations of Doppler velocities at different heights in
the photosphere mapped by eight photospheric lines are presented for
a time span of 45 minutes. The dynamics of the photosphere before and
during a flare which occurred nearby is discussed. <P />We found that
downward plasma motions are well pronounced up to 300 km height in the
photosphere but did not reach deeper layers. The downward velocities of
the plasma motion caused by the flare are about 1.2 km/s and they are
channelled in a thin structure - flux-tube with diameter less than 0.8
arcseconds. The velocities are better noticeable in the active parts
of the target than in the quiet ones. The magnetic configuration of
the active region is compared with the dynamics behaviour.
---------------------------------------------------------
Title: The Height Dependence of Quiet-Sun Photospheric Temperature
Fluctuations in Observations and Simulations
Authors: Koza, J.; Kučera, A.; Rybák, J.; Wöhl, H.
2006ASPC..354...43K Altcode:
We derive rms temperature fluctuations as a function of height
throughout the solar photosphere for the non-magnetic photosphere and
a small area of enhanced magnetic activity, through semi-empirical
inversion based on response functions of a 15-minute time sequence
of 118 arcsec-long slit spectrograms taken at disk center. While the
observed low photosphere shows small temperature fluctuations (about
≈ 50 K), the sub-photospheric layers and the upper photosphere
show larger fluctuations, with similar gradients as in 3-D radiation
discretionary-hydrodynamics simulations. However, the observed rms
temperature fluctuations are lower than in the simulations at all
depths, which we attribute to smearing by atmospheric seeing.
---------------------------------------------------------
Title: A New Method for Comparing Numerical Simulations with
Spectroscopic Observations of the Solar Photosphere
Authors: Rybák, J.; Kučera, A.; Wöhl, H.; Wedemeyer-Böhm, S.;
Steiner, O.
2006ASPC..354...77R Altcode:
A method for comparing high-resolution spectroscopic observations of
the solar photosphere with numerical simulations of convection in the
solar photosphere is presented. <P />It is based on the comparison of
the granular continuum contrast obtained from both the observations and
the synthetic spectra, when the latter are calculated from numerical
simulations using a particular type of data degradation. This method
can be used post facto when a minimum of auxiliary information on
characteristics of the telescope/spectrograph and on seeing conditions
is available. <P />Here, the method is applied to results of numerical
simulations computed with the CO5BOLD code and high-resolution
spectroscopic observations obtained with the VTT on Tenerife.
---------------------------------------------------------
Title: Photospheric modeling through spectral line
inversion. Temperature and radial velocity stratifications and
fluctuations
Authors: Koza, J.; Kučera, A.; Rybák, J.; Wöhl, H.
2006A&A...458..941K Altcode:
Aims.We aim to determine average radial stratifications of various
physical parameters throughout the solar photosphere at high angular
resolution for non-magnetic and magnetic areas and to compare these
with standard semiempirical 1D modeling and with 3D hydrodynamics (HD)
and magnetohydrodynamics (MHD) simulations.<BR /> Methods: .We analyse
a 15-min sequence of adaptive-optics spectrograms of very high angular
resolution taken at solar disk centre. We split the data between a
quiet area and a magnetic one and derive mean temperature and velocity
stratifications and fluctuations for these separately by applying
LTE inversion based on response functions.<BR /> Results: .The mean
temperature stratifications in the non-magnetic region agree well with
the classical 1D models and the 3D simulations at all heights. However,
the observed rms temperature is much lower than in the simulations,
the observed mean velocities indicate more upflows, and the observed
velocity fluctuations are smaller except in upper layers. Some of
the discrepancies are likely to result from remaining smearing by
atmospheric seeing and instrumental limitations. The magnetic area
shows conspicuous behaviour at large height. We also find evidence of
fast low-photosphere downflows in the magnetic area and of enhanced
temperature above a small pore.<BR />
---------------------------------------------------------
Title: Study of a Small-Scale Eruptive Event Observed by SOHO/SUMER
Authors: Tomasz, F.; Régnier, S.; Schwarz, P.; Rybák, J.; Kucera,
A.; Heinzel, P.; Curdt, W.; Wöhl
2006ESASP.617E..79T Altcode: 2006soho...17E..79T
No abstract at ADS
---------------------------------------------------------
Title: Multi-Wavelength Observations with High Resolution of a M5.4
Flare from Ground and Space
Authors: Kucera, A.; Wöhl, H.; Rybák, J.; Gömöry, P.; Veronig, A.
2006ESASP.617E..68K Altcode: 2006soho...17E..68K
No abstract at ADS
---------------------------------------------------------
Title: The Dynamics and Structure of the Solar Atmosphere As Obtained
from Combined SUMER/SOHO and TIP2/VTT Observations
Authors: Tomasz, F.; Régnier, S.; Schwartz, P.; Rybák, J.; Kucera,
A.; Heinzel, P.; Curdt, W.; Wöhl
2006ESASP.617E..78T Altcode: 2006soho...17E..78T
No abstract at ADS
---------------------------------------------------------
Title: SOHO/CDS observations of waves above the network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2006A&A...448.1169G Altcode:
We analyze temporal variations in the intensities and the Doppler shifts
of He i 584.33 Å (chromosphere), O v 629.73 Å (transition region),
and Mg ix 368.07 Å (corona) measured in and above chromospheric
network near disk center with the Coronal Diagnostic Spectrometer
(CDS) onboard the Solar and Heliospheric Observatory (SOHO). There is
significant correlation between the He i and O v modulations, with O v
intensity leading He i intensity by 27.3 s ± 4.6 s but no significant
time shift in the Doppler shift. Cross-correlation between the O v
and Mg ix intensities reveals multiple maxima without correlation
between their Doppler shifts. Wavelet power analysis gives evidence
of intermittent chromospheric and transition-region oscillations with
periodicities in the 250-450 s range and of coronal oscillations in
the 110-300 s range. Wavelet phase difference analysis shows that
the determined time shift between variations of the He i and O v
intensities is dominated by waves with about 300 s periodicity. We
interpret these results as giving evidence of compressive waves that
propagate downward from the transition region to the chromosphere in
the particular chromospheric network. We discuss different scenarios
regarding origin and source localization of waves, and we speculate
on their role in coronal heating above chromospheric network.
---------------------------------------------------------
Title: Acoustic Flux and Turbulence in the Solar Photosphere
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
2006CEAB...30...11H Altcode:
Using slit scans of solar photospheric spectral lines originating in
the middle photosphere a 2-D field on the Sun was obtained and the
occurrence of acoustic flux is investigated. As proxies for acoustic
flux generation enhanced turbulence (measured by fwhm variations) as
well as large continuum intensity values are used. The results show
that acoustic flux is not limited to the intergranular space and is
also produced by horizontal motions that may become supersonic leading
to turbulence. These motions lead to brightenings as it was predicted
by theoretical models.
---------------------------------------------------------
Title: Influence of the 5-min oscillations on solar photospheric
layers. I. Quiet region
Authors: Odert, P.; Hanslmeier, A.; Rybák, J.; Kučera, A.; Wöhl, H.
2005A&A...444..257O Altcode:
Time series of 1D spectrograms are used to study the influence of the
5-min oscillations on intensity and velocity fields of different layers
of the quiet solar photosphere. We study the continuum intensity field
along with intensity and corresponding velocity patterns of the mid and
upper photosphere, obtained from two Fe lines. Oscillations seem to
dominate the intensity and velocity fields of the higher atmospheric
layers. Our results confirm the fast decay of the granular intensity
structure with height. From correlations of temperature structures
at three different photospheric levels we conclude that there are
rapid changes of the structures in the lower photosphere, which are
valid for the duration of the time series, while for the upper levels
changes of the stuctures are fainter and show significant periodic
character. The velocity pattern, on the other hand, shows a periodic
propagation through the photosphere. The tests of the influence of
seeing conditions on the data are considered.
---------------------------------------------------------
Title: Analysis of Dynamics of Loops in AN Active Region Associated
with a Small C-Class Flare
Authors: Gömöry, P.; Rybák, J.; Kucera, A.; Wöhl, H.
2005ESASP.596E..56G Altcode: 2005ccmf.confE..56G
No abstract at ADS
---------------------------------------------------------
Title: Response Functions of Spectral Lines Suitable for Diagnostics
of Solar Rotation
Authors: Koza, J.; Kučera, A.
2005HvaOB..29...21K Altcode:
The response functions for temperature and line-of-sight velocity
of the medium-strong Fe II, strong Fe I and weak N II spectral lines
are examined. The lines were previously used for determination of the
depth dependence of the solar rotation velocity. The positions of local
maxima of the response functions to temperature and the calculated
optical depths of formation of line cores are confronted. The close
coincidence of these quantities is demonstrated and thus verifying
the correctness of the optical depth scale of the investigated solar
<P />rotation profile.
---------------------------------------------------------
Title: Analysis of Doppler Shifts of Spectral Lines Obtained by the
CDS/SOHO Instrument
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2005ASSL..320..203G Altcode: 2005smp..conf..203G
No abstract at ADS
---------------------------------------------------------
Title: On the Behaviour of a Blinker in Chromospheric and Transition
Region Layers
Authors: Tomasz, F.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2005ASSL..320..207T Altcode: 2005smp..conf..207T
No abstract at ADS
---------------------------------------------------------
Title: Variability and Dynamics of the Outer Atmospheric Layers in
the Quiet Solar Network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2005HvaOB..29...71G Altcode:
A detailed study of the temporal evolution of the chromospheric He
I 584.33 Å and the transition region O V 629.73 Å emission line
intensities of quiet supergranular network of the Sun near disk centre
observed with Coronal Diagnostic Spectrometer (CDS) is presented. A
wavelet analysis of the 1729 s (28.8 min) long temporal series was
performed in order to derive the duration as well as periods of the
chromospheric and the transition region oscillations. The He I line
intensities show significant power for periods around 300 s (3.3 mHz),
which is relevant only in the second half of the observing sequence
(between 800 -- 1700 s). The temporal evolution corresponding to the
O V line intensities shows strong power around the period of 400 s
(2.5 mHz), which is significant during the whole observing sequence
as well as the oscillation of lower power for periods of around 250 s
(4.0 mHz), which is present only in the middle of the observing sequence
(between 700 -- 1300 s).
---------------------------------------------------------
Title: High Resolution Observations of a M5.4 Flare
Authors: Kučera, A.; Wöhl, H.; Rybák, J.; Gömöry, P.; Tomasz, F.
2005HvaOB..29..177K Altcode:
Hα observations of a M5.4 flare taken in the active region NOAA 10646
with the Vacuum Tower Telescope at Observatório del Teide, Tenerife,
on July 13, 2004 are presented. The temporal evolution of the area
of the flare and its morphological changes are investigated and
discussed. Simultaneous observations of the flare in EUV lines taken
with CDS/SOHO instrument are shown and additional data from GOES-10
instrument are compared.
---------------------------------------------------------
Title: Influence of Transition Region Blinker on the Surrounding
Chromospheric and Coronal Plasma
Authors: Tomasz, F.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2005HvaOB..29..197T Altcode:
Results of spectral analysis of a blinker observed in the transition
region O VI 1037.63 Å line and in the chromospheric Ly β 1025.72
Å line which were acquired using the SUMER spectrometer are
presented. Chromospheric and coronal plasma in the vicinity of the
blinker are investigated using also TRACE Ly α, UV continuum and Fe IX
channels. It was found that initial release of energy was localized in
the transition region and plasma has been spreading from transition
region as a bi-directional jet. Energy reached chromosphere ∼60
seconds after primary emission in the o6 line. There were detected
enhanced emissions for about 25-38% in the chromospheric Lyα and UV
continuum. Spatial extent of the blinker response is 6” along the slit
in the Lyα filtergram what is ∼3” less than extent of the blinker
in the o6 line. Maximum extent of the blinker response is 7.5” in
Lyα filtergram. Although, both Lyα and UV continuum reflect physical
conditions in chromosphere, their patterns are completely different:
pattern of the blinker response is compact in the Lyα and UV continuum
shows non-compact structure below the transition region blinker. Coronal
plasma was not influenced by the blinker although plasma moving toward
observer was detected in the final phase of evolution of the blinker.
---------------------------------------------------------
Title: Observational Evidences for Heating of the Solar Corona
by Nanoflares in the Network Derived from the Transition Region
Spectral Lines
Authors: Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
2004ESASP.575..529R Altcode: 2004soho...15..529R
No abstract at ADS
---------------------------------------------------------
Title: Dynamics of the Quiet Upper Solar Atmosphere in the Network
Authors: Gömöry, P.; Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
2004ESASP.575..400G Altcode: 2004soho...15..400G
No abstract at ADS
---------------------------------------------------------
Title: Two-dimensional spectroscopic time series of solar granulation
Authors: Hanslmeier, A.; Kucera, A.; Rybák, J.; Wöhl, H.
2004SoPh..223...13H Altcode:
In this paper we investigate the dynamics of the solar granulation
by analyzing time series of 2D spatially highly resolved
spectrograms. These were obtained by spatial scans covering a field
of 12 8″ × 20″. The advantage of this method is a high spectral
resolution, however, the data are not taken simultaneously and to
cover the field described above 50 exposures taken sequentially in
time are necessary. Therefore, to obtain one map about 2 minutes are
required. Plots of the evolution of different line parameters are
given as well as the decay of correlation functions. The correlations
between the first map of line parameters and successive maps (which are
separated by about 2 minutes) were investigated showing a rapid decay
down to a correlation coefficient of 0.4 within 4 minutes, the velocity
pattern in the field observed varies on smaller time scales. The
temporal variation of correlation between the line parameters for the
different lines shows a periodic signal related to 5-min oscillations
which could not be totally filtered. The evolution of the correlation
functions between line parameters is analyzed which gives an error
estimate of all correlation values found in the literature. For
the first time it is explicitly shown how evolution in a selected
photospheric field influences the evolution of granular/intergranular
structures.
---------------------------------------------------------
Title: Indications of shock waves in the solar photosphere
Authors: Rybák, J.; Wöhl, H.; Kučera, A.; Hanslmeier, A.;
Steiner, O.
2004A&A...420.1141R Altcode:
High resolution observations of solar granulation near the solar limb
are used in a search for hydrodynamic shocks caused by an abrupt
braking of the fast (probably supersonic) horizontal flow of the
granular plasma towards the intergranular lane. Shock signatures in
the spectral line of Fe II 6456.38 Åof one particular observed shock
event are investigated in detail. Evolution, amplitude, and spatial
relation of the spectral line characteristics of the shock event are in
agreement with predictions from numerical simulations for such shock
phenomena in the solar photosphere. The dimensions and amplitudes of
the observed shock signatures are comparable to predicted values when
seeing and instrumental effects as well as a possible obliqueness of
the shock front with respect to the observer's line-of-sight are taken
into account. The temporal evolution of such an event is observed for
the first time. The stable and declining phase of the event were studied
for a time period of almost 2 min. A particular relationship was found
between the shock event and a nearby G-band bright point located 2”
from the shock event. It is suggestive that the observed shock is a
causal consequence of the magnetic flux concentration, traced by the
G-band bright point. Such a type of shock can appear outside the flux
concentrations as a consequence of a rapid flux-tube motion.
---------------------------------------------------------
Title: On Relations among the Calibrated Parameters of the Transition
Region Spectral Line
Authors: Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
2004ESASP.547..311R Altcode: 2004soho...13..311R
SUMER/SOHO measurements of the O VI 1031.93 Å emission line (280000
K) in the network and internetwork of the transition region of the
quiet solar atmosphere are used for a statistical analysis of the
calibrated spectral parameters: the central line intensity (energetic
units), the line width (m Å) and the Doppler shift (km/s). A detailed
procedure is performed in order to determine the absolute wavelength
calibration of the spectra and Doppler shifts using simultaneously
observed chromospheric O I 1027.44 Å and 1028.15 Å emission lines
(10 000K). The spectral parameters of the O VI line are derived for
both single and double Gaussian fitting of the line according to the
latest findings on the multi-component nature of the transition region
line profiles. Reliability of the absolute wavelength calibration and
effects of two classes of the transition region transient events -
explosive events and blinkers - are discussed in relation to the
overall dependencies of the spectral parameters.
---------------------------------------------------------
Title: On Mutual Relation Among the Outer Atmospheric Layers in
Network: SOHO/CDS Study
Authors: Gömöry, P.; Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
2004ESASP.547..303G Altcode: 2004soho...13..303G
SOHO/CDS measurements of emission in the network of the quiet solar
atmosphere near disk center were used to derive mutual relations
of emission and dynamics in different temperature regimes in/above
supergranular network. Cross-correlation functions of the line
intensities and the Doppler shifts of the chromospheric line He I 584.3
Å, the transition region line O V 629.7 Å and the coronal line Mg
IX 396.1 Å were calculated in order to study relative variability
of different atmospheric layers. Relatively high correlations were
found between the intensities and the Doppler shifts of the He I and
O V lines with two peaks of the intensity correlation function. The
maximum value of the correlation of intensities (CC = 0.86) was reached
for the zero time lag and the second maximum (CC = 0.78) was obtained
for the time lag -190s (O V precedes He I). Only one sharp peak (CC =
0.55) was detected in the Doppler shift correlation function of these
lines for the zero time lag. For the correlation of O V and Mg IX
intensities one peak (CC = 0.57) of the correlation function was also
discovered for the time lag +150s (Mg IX falls behind O V). In contrast,
no correlation was obtained for the Doppler shifts of the O V and Mg
IX lines. Summarizing we can assume clear relation in energy transfer
and/or mass motion between chromosphere and transition region but no
relation was found between corona and the lower parts of the solar
atmosphere above the particular network under study.
---------------------------------------------------------
Title: Velocity field in the intergranular atmosphere
Authors: Kučera, A.; Koza, J.; Bellot Rubio, L. R.; Hanslmeier, A.;
Rybák, J.; Wöhl, H.
2004HvaOB..28...19K Altcode:
The line-of-sight velocity ľand macroturbulent velocity are studied
in the centre of the intergranular space in the solar photosphere. An
inversion method is applied to a 4-min time sequence of Stokes
I spectra of the 5, 6 and 7 lines observed with high spatial and
temporal resolutions at solar disk centre. The results are presented
in the form of the functional dependence of ľ(logτ<SUB>5</SUB>,t)
and (t) on the continuum optical depth τ<SUB>5</SUB> at 500 nm and
time t. A ľof several hundreds of meters per second was found in the
upper photosphere (logτ<SUB>5</SUB>≤-1.5), where the plasma flows
away from the observer. On the contrary, upflows directed toward the
observer were found in deeper layers (logτ<SUB>5</SUB>>-1.5). The
typical value of in the centre of the intergranular space is found to be
∼1.7 kms, which is about 0.5 kms greater than in the adjacent granule.
---------------------------------------------------------
Title: SUMER/SOHO and TRACE Study of the Transition Region Blinker
Authors: Tomasz, F.; Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
2004ESASP.547..307T Altcode: 2004soho...13..307T
The most prominent transient event is presented from an extensive
search for the transition region internetwork activity in the quiet
solar atmosphere performed by SUMER/SOHO spectrometer and TRACE. SUMER
spectra of Ly line (1025.4 Å), two C II lines (1036.3 Å, 1037.0 Å)
and O VI line (1037.61 Å) were used for determination of the spatial
and temporal evolution of the transient event in the transition
region. TRACE images taken in the 1216 Å passband, UV continuum
(1700 Å) and Fe IX line (171 Å) were utilized in order to gain
information about large-scale coronal structures and small-scale
chromospheric variability in the vicinity of the transient event. The
main physical and geometrical parameters of the event were derived
for the transition region O VI line: the spatial extent of 11 000 km,
duration for 9 minutes, intensity enhancement factor of 7 and the
Doppler velocities of both signs up to 15 km/s. According to these
values the event was identified as a transition region blinker. High
deviations of the acquired O VI line profiles from single-Gaussian and
some multi-Gaussian profiles reveal dynamics of the event - occurrence
of the bidirectional jet which is not typical for blinkers. Besides
rapid changes in intensity and in velocity, a rapid increase by a
factor of 4.2 was found in the Gaussian width of O VI line as compared
to the internetwork. Surrounding chromospheric and coronal structures
around the event are discussed on base of the simultaneously taken
TRACE images.
---------------------------------------------------------
Title: One-dimensional spectroscopy of the solar photosphere
Authors: Odert, P.; Hanslmeier, A.; Rybák, J.; Kučera, A.; Wöhl, H.
2004HvaOB..28...37O Altcode:
Data from a time series of spectrograms were used to study
correlative relationships between intensity and velocity in the solar
photosphere. The variations along the slit of the line parameters from
two Fe lines lying in the visible range of the spectrum were used. The
formation height difference of these lines is over 300 km. The temporal
variations of the correlation coefficients were studied, they showed
a strong influence of the 5 min-oscillations.
---------------------------------------------------------
Title: Proper motions of sunspots - new data and further results
Authors: Wöhl, H.; Brajša, R.; Kučera, A.; Ruždjak, V.; Rybák, J.
2004HvaOB..28...47W Altcode:
The attempts to investigate patterns of motions of main spot components
and small pores in complex sunspot groups were continued. The data
discussed stem mainly from observations at Hvar/HR and Tatranská
Lomnica/SK. Two historic collections of photographic plates are
included: The plate archives of the former Fraunhofer Institute and
that of photographic plates taken at Skalnate Pleso/SK.
---------------------------------------------------------
Title: The range of reliability of the line-of-sight velocity in a
semiempirical model of a granule
Authors: Koza, J.; Kučera, A.
2003CoSka..33..224K Altcode:
Stokes I response functions to the line-of-sight velocity
v<SUB>LOS</SUB> of two medium-strong Fe I 522.5 nm and Fe I 557.6 nm
lines and the weak line Fe I 557.7 nm have been calculated using a
semiempirical 1D model of the granular photosphere affected by 5-min
oscillations. A new method is presented allowing to estimate the range
of optical depths within which the inferred values of an atmospheric
parameter can be considered as reliable. The sensitivity of the
individual lines to the variations of v<SUB>LOS</SUB> is examined and
the range of reliability of v<SUB>LOS</SUB> is estimated applying the
new method. It is shown that for the given line set the Fe I 522.5 nm
line is the most sensitive one and, in turn, the Fe I 557.7 nm line
has very low sensitivity to the variations of v<SUB>LOS</SUB>. In
the case of the Fe I 522.5 nm line the impact of a v<SUB>LOS</SUB>
perturbation on the intensity of a profile point is about 50% greater
than that on the Fe I 557.6 nm line. As a consequence of evolution of
the physical conditions in a granule the range of reliability of the
model varies and it consists of two separate regions occupying the
lower and upper photosphere.
---------------------------------------------------------
Title: Dynamics and turbulence of the chromospheric layers of a
flaring atmosphere
Authors: Brčeková, K.; Kučera, A.; Hanslmeier, A.; Rybák, J.;
Wöhl, H.
2003AN....324..366B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Transition region blinker - spatial and temporal behaviour
Authors: Tomasz, F.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2003HvaOB..27...75T Altcode:
From an extensive search for transition region internetwork activity
in the quiet Sun atmosphere the most prominent transient event is
presented. The basic physical and geometrical parameters of this event
are derived from the O VI 1037.61 Å emission spectral line. The spatial
extent of 11 000 km, duration for 9 minutes, intensity enhancements
factor of 7 and large Doppler velocities of both signs were estimated
for the event. According to these values this event was identified as
a transition region blinker.
---------------------------------------------------------
Title: Proper motions of sunspot groups
Authors: Wöhl, H.; Brajša, R.; Kučera, A.; Ruždjak, V.; Rybák, J.
2003HvaOB..27....1W Altcode:
Attempts to investigate typical patterns of motions of main spot
components and small pores in complex sunspot groups are described. The
data used up to now stem from observations at Hvar/HR, Tatranská
Lomnica/SK, Izaña/E, Debrecen/H and from the MDI instrument on
SoHO. Preliminary results are presented.
---------------------------------------------------------
Title: Evolution of temperature in granule and intergranular space
Authors: Koza, J.; Bellot Rubio, L. R.; Kučera, A.; Hanslmeier, A.;
Rybák, J.; Wöhl, H.
2003AN....324..349K Altcode:
The temporal evolution of temperature in a dissolving granule and
in an adjacent intergranular space is presented. The semi-empirical
evolutionary models have been calculated using an inversion method
applied to 4-min time series of Stokes I spectral line profiles. The
models are presented in the form of the functional dependence of
temperature T(log tau_5 ,t) on optical depth tau_5 at 500 nm and time
t. The observed disappearance of the granule is accompanied with overall
cooling of the granular photosphere. Temperature changes greater than
100 K have been found in deeper (log tau_5 >=0) and upper layers
(log tau_5 <=-2) whereas the intermediate layers are thermally
stable. The intergranular space, which is 2 arcsec off the granule,
keeps the temperature structure of the layers from log tau_5 =0.5 to
log tau_5 =-2 without global evolutionary changes except short-term
and spatially confined heating. Finally, the significant temperature
changes in the upper layers (log tau_5 <=-2.5) observed during the
time interval of 4 min are found to be typical for the granular and
intergranular photosphere.
---------------------------------------------------------
Title: Observational evidence for a shock event in the solar
granulation
Authors: Kučera, A.; Rybák, J.; Hanslmeier, A.; Wöhl, H.
2003HvaOB..27...25K Altcode:
High resolution spectra of Fe II 6456.39 Å line are used to investigate
a shock in the solar granulation. The changes of the main spectral
characteristics measured in the shock area are in a good agreement with
the characteristics predicted with theory. The analysis of the shock,
made in the past by several authors was extended in this work to the
analysis of a temporal development of the shock event. The 2 minutes
duration of a stable and declining phases of the event was studied. We
conclude that the observed shock belonged to the particular type of
shock generated as a consequence of the swaying motion of the magnetic
flux tube concentrated in the intergranular lane. Such type of shock
was proposed by numerical simulations made by Steiner et al. 1998.
---------------------------------------------------------
Title: Transition region eruptive event observed with SOHO/CDS in
the quiet Sun network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
2003HvaOB..27...67G Altcode:
CDS observations of the quiet Sun network in the chromospheric He I
584.33 Å and transition region O V 629.73 Å emission lines over
a time period of ∼ 29 min are presented. One eruptive event was
detected in this time series of data. The parameters of the network
eruptive event are derived and the type of this small-scale activity
is identified. The lifetime of the event was ∼ 1 min and it was
found only in the transition region emission line. This event had no
chromospheric counterpart. All O V spectral profiles of the eruptive
event were blueshifted and the maximal Doppler shift was -14.7 km
s<SUP>-1</SUP>. During an initial phase of the eruptive event, the
O V intensity enhancement factor was 2.3. These parameters indicate
that the observed event could be a transition region explosive event
but measured with the limited resolution of the CDS instrument.
---------------------------------------------------------
Title: Line intensities of chromospheric and photospheric spectra
of a flare
Authors: Brčeková, K.; Kučera, A.; Hanslmeier, A.; Rybák, J.;
Wöhl, H.
2002ESASP.506..557B Altcode: 2002ESPM...10..557B; 2002svco.conf..557B
In this work we present the intensities of spectral lines determined
from the time series of high resolution spectra obtained during
the relaxing phase of subflare. The spectra were taken in the core
of chromospheric Ca II K line and in two photospheric Fe I 522.5 nm
and Fe I 557.6 nm lines. It is shown, that the energy of the flaring
chromosphere slightly affects the underlying photospheric layers by
heating a small area right under the core of the subflare.
---------------------------------------------------------
Title: Two-dimensional spectroscopic time series of solar granulation:
evolution of individual granules
Authors: Hanslmeier, Arnold; Kučera, Ales; Rybák, Jan; Wöhl,
Hubertus
2002ESASP.506..633H Altcode: 2002svco.conf..633H; 2002ESPM...10..633H
In this paper we investigate the dynamics of the solar granulation by
analyzing time series of 2-D spatially highly resolved spectrograms. The
high quality of the data permitted us to follow the evolution of
individual granular and intergranular areas. We used scans over the
solar surface in order to obtain a 2-D information. This has the
advantage of achieving high spectral and spatial resolution, however
one scan lasted for about 2 min.
---------------------------------------------------------
Title: Line-of-sight velocity in a semiempirical model of a
disappearing granule
Authors: Koza, J.; Bellot Rubio, L. R.; Kučera, A.; Hanslmeier, A.;
Rybák, J.; Wöhl, H.
2002ESASP.506..443K Altcode: 2002svco.conf..443K; 2002ESPM...10..443K
The behaviour of the line-of-sight velocity in the centre of a
disappearing granule is analyzed using an inversion method applied
to a time-series of spectra containing the Fe I 522.5 nm, 557.6
nm and 557.7 nm lines. The temporal evolution of the line-of-sight
velocity v<SUB>LOS</SUB> is presented in the form of the functional
dependence of v<SUB>LOS</SUB>(logτ<SUB>5</SUB>, t) on the optical
depth τ<SUB>5</SUB> at 500 nm and time t. An oscillatory behaviour
is found in the velocity stratification with nearly constant phase
through the photosphere. The amplitude of variations increases from
logτ<SUB>5</SUB> = -0.3 to logτ<SUB>5</SUB> = -2.5 reaching a maximum
of ~1.2 km s<SUP>-1</SUP>. A zero velocity layer is detected in every
instantaneous model of the velocity stratification. The results suggest,
that the zero velocity may occur in a considerable range of the optical
depths from logτ<SUB>5</SUB> ~ -2 to logτ<SUB>5</SUB> ~ -3.5.
---------------------------------------------------------
Title: Precise reduction of solar spectra obtained with large
CCD arrays
Authors: Wöhl, H.; Kučera, A.; Rybák, J.; Hanslmeier, A.
2002A&A...394.1077W Altcode:
A precise procedure suitable for the reduction of solar spectra
taken with large CCD arrays and the retrieval of correct spectral
characteristics is presented. Various effects, which one should take
into account, are considered and several improvements of the standard
reduction are introduced. A special flat-field procedure is suggested
for the reduction of spectra registered in different flat-field
conditions than those when the flat-field matrix was taken. The original
flat-field matrix is split into several components to eliminate the
influence of the drift of the spectrograph and temporal changes of
the flat-field conditions on the reduced spectrum. The importance
of every flat-field matrix component is tested and discussed and the
noise propagation through data reduction is analyzed. It is documented
that the errors of the basic spectral line characteristics, continuum
intensity, line centre intensity and full width at the half maxima
of the line have variations between 0.5% and 15% and the errors of
the line centre Doppler velocity and bisectors fluctuate by up to 200
m s<SUP>-1</SUP>, if derived from imprecise reductions, compared to
precise ones.
---------------------------------------------------------
Title: Temporal evolution of physical parameters in granule
Authors: Koza, J.; Kucera, A.; Hanslmeier, A.; Rybák, J.; Wöhl, H.
2002ESASP.505..457K Altcode: 2002solm.conf..457K; 2002IAUCo.188..457K
The temporal evolution of the physical parameters inside a granule
is presented. This is a step towards a more realistic 1D modeling
of the solar granulation, avoiding the temporal averaging used up
to now. The granulation is treated as a dynamical phenomenon and our
model has been calculated using an inversion method applied to time
series of spectra. The granular evolutionary model is presented in
the form of the functional dependence of temperature T(log τ, t) and
line-of-sight velocity v<SUB>LOS</SUB>(log τ, t) on optical depth τ
and time t. The observed disappearance of the granule is accompanied
with significant temperature changes greater than ~300K in deeper layers
(log τ<SUB>5</SUB> > 0) and upper layers (log τ<SUB>5</SUB> <
-2.5). In contrary, the layers from log τ<SUB>5</SUB> ~= -0.5 to log
τ<SUB>5</SUB> ~= -1.5 are more stable in the sense of temperature
variations, which are less than ~150K. An oscillatory behavior is
found in the line-of-sight velocity stratification from log τ5 ~= 0
upwards with increasing amplitude reaching up to ~= 2 km s<SUP>-1</SUP>
in upper layers.
---------------------------------------------------------
Title: Spectral line response to temperature perturbation in solar
and stellar photospheric models. I. Neutral Fe I line 522.5nm case
Authors: Koza, J.; Kučera, A.
2002CoSka..32..190K Altcode:
The sensitivity of the line profile of the neutral Fe I 522.5nm line to
Gaussian perturbations of temperature distribution in the photospheric
models is examined. Stokes I response functions to temperature of
the Fe I 522.5nm line have been calculated using different classes
of the solar photospheric models. In the LTE approximation three
one-component models HOLMU, HSRA, VAL3C and a new two-component
photospheric model are tested. In the (log τ<SUB>5</SUB>, λ) plane
the response functions have been calculated for all four models. It
is shown that in the case of one-component models, the temperature
perturbation in the upper photospheric layers only affects the core
of the line profile and in contrast, the temperature perturbation
of the deep photosphere affects only the line-wings. This is not the
case in the two-component model, where the heating or cooling of the
upper photosphere significantly modifies not only the line-core but
also the wings. A detailed examination of this effect is presented and
discussed to point out the incompatibility of simplified one-component
models with the real physical conditions of the stellar photosphere.
---------------------------------------------------------
Title: Dynamic coupling of the chromospheric and photospheric
flaring plasma
Authors: Brceková, K.; Kucera, A.; Hanslmeier, A.; Rybák, J.;
Wöhl, H.
2002ESASP.505..357B Altcode: 2002solm.conf..357B; 2002IAUCo.188..357B
The relaxing phase of the subflare observed in the core of chromospheric
Ca II K line and in two photospheric Fe I 522.5 nm and Fe I 557.6 nm
lines was investigated. The temporal evolution of asymmetry in Ca II
K line and the mean bisectors positions of the Fe I line profiles as
well as their correlations are presented. It is documented that the
chromospheric down-flow caused by the subflare strongly affects the
upper layers of the photosphere. As a consequence of relaxation of
the photospheric layers strong down-flows and up-flows were measured
at the end of the subflare relaxing phase.
---------------------------------------------------------
Title: High-resolution CCD spectra reduction: temporal changes of
the flat-field compensation
Authors: Kučera, Aleš; Hanslmeier, Arnold; Rybák, Ján; Wohl,
Hubertus
2002NCimC..25..703K Altcode:
A new method suitable for long-time series of high-resolution CCD
spectra reduction is presented. The method allows to compensate the
temporal changes of the instrument conditions which leads to temporal
changes of the flat-field matrix. Sometimes it is impossible to make
the flat-field measurements during long simultaneous observations with
satellites (SOHO, TRACE). The method splits the flat-field matrix into
two components. The first one, connected with CCD camera is stable in
time and is correct for all spectra. The second one varies and reflects
temporal changes of the conditions in the spectrograph. Description
of the method and its application to real high-resolution CCD spectra
is presented and discussed.
---------------------------------------------------------
Title: Transition region dynamics from SUMER/SOHO observations:
shape of the emission spectral lines
Authors: Rybák, J.; Curdt, W.; Kučera, A.; Wöhl, H.
2002ESASP.477..163R Altcode: 2002scsw.conf..163R
The quiet sun network/internetwork transition region line profiles
of C II 1036.34 Å and O VI 1037.61 Å are outlined emphasizing
the temporal/spatial behaviour of their deviations from the
Gaussian shape. Systematic deviations of the line profiles from the
single-Gaussian shape indicate that transition region emission lines
consist of two Gaussian components over almost the whole quiet sun
internetwork except their small innermost parts. This finding is in
qualitative agreement with the transition region model of Peter (2001).
---------------------------------------------------------
Title: Joint Organization for Solar Observations, Annual Report
2000/2001, Vol. 30/31.
Authors: Kucera, A.
2002joso.book.....K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Minutes of the 33rd JOSO Board Meeting - 2001
Authors: Cauzzi, G.; Kucera, A.; Schmieder, B.
2002joso.book...15C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: JOSO national report 2000-2001 - Slovakia. Solar research in
Slovak Republic 2000-2001
Authors: Kucera, A.
2002joso.book..100K Altcode:
Solar research in Slovak Republic is carried out at three following
institutions: (1) Astronomical Institute, Slovak Academy of Sciences
(AISAS), Tatranská Lomnica (2) Astronomical Institute, Comenius
University (AICU), Bratislava (3) Slovak Central Observatory, Hurbanovo.
---------------------------------------------------------
Title: Minutes of the 32nd JOSO Board Meeting - 2000
Authors: Cauzzi, G.; Kucera, A.; Schmieder, B.
2002joso.book...10C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Location of Solar Oscillations in the Photosphere
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
2001ASSL..259..267H Altcode: 2001dysu.conf..267H
Applying a correlation analysis to time series of granulation it has
been shown that due to the influence of enhanced turbulent motions
near the downflow regions in the intergranular lanes the turbulent
motions predominate.
---------------------------------------------------------
Title: Chromospheric Dynamics as can be Inferred from SUMER/SOHO
Observations
Authors: Rybák, J.; Kučera, A.; Curdt, W.; Schühle, U.; Wöhl, H.
2001ASSL..259..247R Altcode: 2001dysu.conf..247R
Experience with the SUMER/SOHO observations of the chromospheric
dynamics and the reduction of the acquired data is summarized on
base of the SOHO Joint Operation Program 78 which is focused on the
variability of the chromosphere and the transition region to the corona.
---------------------------------------------------------
Title: Dynamics of the Upper Photosphere: Coherence and Phase Analysis
(CD-ROM Directory: contribs/hanslmei)
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
2001ASPC..223..669H Altcode: 2001csss...11..669H
No abstract at ADS
---------------------------------------------------------
Title: Correlative relationships in an inhomogeneous solar atmosphere
Authors: Gadun, A. S.; Hanslmeier, A.; Kučera, A.; Rybák, J.;
Wöhl, H.
2000A&A...363..289G Altcode:
We analyse the correlative relationships between various quantities
derived from 2-D inhomogeneous and time-dependent model atmospheres
and between selected simulated line parameters to compare them with
height-dependent correlations derived from spectral observations. We
detect three photospheric regions: thermal convection, overshooting
convection and a transition layer. We also show that correlations
found for the model data and those computed within simulated spectral
observations are a good testing tool for line formation depths. As
an example, we examine two criteria, providing heights of line core
formation in LTE, and conclude that the approach which defines
this quantity as geometrical height at line center optical depth
τ<SUB>λ0</SUB> = 1 is likely more suitable for diagnostic purposes
than the method based on depression contribution function.
---------------------------------------------------------
Title: Dynamics of the upper solar photosphere
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Neunteufel, B.;
Wöhl, H.
2000A&A...356..308H Altcode:
The dynamics of the upper solar photosphere was studied by using
1-D photospheric line spectrograms obtained using the VTT of the
Observatorio del Teide. Three spectral lines with line core formation
heights between 250 and 500 km were analyzed. It is clearly seen that at
these levels the velocity and intensity fields are highly correlated
but different from the lower lying zone where convective motions
predominate. This is shown by classical methods (using correlations and
bisectors) as well as by applying the Hurst exponent method to the data.
---------------------------------------------------------
Title: 3-D Tomography of the Solar Photosphere
Authors: Hanslmeier, A.; Kucera, A.; Rybak, J.; Wohl, H.
2000ESASP.463..333H Altcode: 2000sctc.proc..333H
No abstract at ADS
---------------------------------------------------------
Title: Spectral Statistics of Fe I and Ca II K Lines in the Quiet
and Active Solar Atmosphere
Authors: Kucera, A.; Brcekova, A. K.; Hanslmeier, A.; Rybak, J.;
Woehl, H.
2000HvaOB..24..111K Altcode:
Based on two Fe I and Ca II K lines spectra obtained with high spatial
and spectral resolution we investigated some spectral characteristics
of these lines in quiet and active regions. In this paper we present
the behaviour of the central line intensities in different types of
solar activity. We discuss the obtained results and compare them with
the results reported by other authors.
---------------------------------------------------------
Title: Two Dimensional Spectral Time Series
Authors: Hanslmeier, A.; Kucera, A.; Rybak, J.; Woehl, H.
2000HvaOB..24...81H Altcode:
We analyze two dimensional time series of solar photospheric
spectrograms in order to study the dynamics of solar fine structures and
their evolution. The two dimensional images were obtained by scanning
over the photosphere. Spectrographic data of this type include a much
higher information than ordinary images.
---------------------------------------------------------
Title: Interaction of Sunspots with the Surrounding Plasma - a
Progress Report
Authors: Woehl, H.; Rybak, J.; Kucera, A.
2000HvaOB..24..119W Altcode:
The historic development of the search for interactions of sunspots
and solar plasma around them was given in a contribution at the IVth
Hvar Astrophysical Colloquium (Woehl, 1997). It was concentrated on
the results of measurements and their reductions performed by Lustig
and Woehl (1993), showing a dependence of plasma velocity difference
in front and behind stable sunspots depending on their relative speed
within the plasma. Since the result obtained was not significant,
new attempts were started to use MDI/SoHO data and mainly to collect
data ourselves at telescopes and the horizontal spectrometer of the
Astronomical Institute of the Slovak Academy of Sciences in Tatranska
Lomnica, Slovakia. The main difference is that now the plasma velocity
data are gained by a matrix of fiber optics collecting light at several
positions around the sunspot. In addition the sunspot positions are
collected by a different telescope. The reductions of the sunspot
positions give very reliable rotation data and - as expected - very
small meridional motions, while the plasma velocity data are not yet
reliable. Attempts to improve this situation are described.
---------------------------------------------------------
Title: Fe I and Ca II K Lines in Quiet and Active Regions
Authors: Kucera, A.; Brcekova, K.; Hanslmeier, A.; Rybak, J.; Wohl, H.
2000ESASP.463..357K Altcode: 2000sctc.proc..357K
No abstract at ADS
---------------------------------------------------------
Title: Chromospheric and Transition Region Dynamics - Reasons
and Consequences of the Long-period Instrumental Periodicities
of SUMER/SOHO
Authors: Rybák, J.; Curdt, W.; Kucera, A.; Schühle, U.; Wöhl, H.
1999ESASP.448..361R Altcode: 1999mfsp.conf..361R; 1999ESPM....9..361R
No abstract at ADS
---------------------------------------------------------
Title: Chromospheric And Transition Region Dynamics - Reasons
and Consequences of the Short Period Instrumental Periodicities
of SOHO/SUMER
Authors: Rybak, Jan; Curdt, Werner; Kučera, Ales; Schüehle, Udo;
Wöehl, Hubertus
1999ESASP.446..579R Altcode: 1999soho....8..579R
The instrumentally caused oscillations of the spectral lines intensity
and velocity, determined with the SUMER spectrometer onboard SoHO, are
presented. On examples of two long-term measurements of O I, C II and O
VI lines, it is shown that the reason of this instrumental effect was
the insufficient precision of the solar rotation compensation of the
spectrometer slit position. In both observational runs the standard
rotation compensation procedure, performed on-line by the instrument,
was selected for the long-term observations. The minor periodical
motion of the slit position on the solar disk was taking place during
such observations and this effect produced the regular changes of the
measured line intensities and velocities. The significant enhancements
of the oscillations amplitudes around the frequency 2.56 mHz and its
harmonics were detected in the cases of observations, performed at
the disk center. Unfortunately, these frequencies are just in the
range of the typical oscillations determined till now in the upper
solar atmosphere ! Consequences of this instrumental effect for SUMER
measurements of the chromospheric and transition region dynamics
are discussed. Procedures how to exclude the effect from the data
post-facto as well as how to modify the future SUMER oscillations
measurements in order to avoid the effect are proposed
---------------------------------------------------------
Title: Fiber Optics Device for Solar Spectroscopy - First Measurements
Authors: Kucera, A.; Rybák, J.; Wöhl, H.; Hanslmeier, A.
1999ASPC..184..319K Altcode:
In 1996 we introduced the fiber optics device designed for 2D
solar spectroscopy (Kucera et al. 1997). Now we present the first
results obtained within last year. First experiences with wavelength
calibration, light transmission through the fibers, noise reduction,
software for reduction of observations and preliminary results of
reduced scientific data are presented.
---------------------------------------------------------
Title: SOHO JOP 078 - variability and properties of the quiet sun
supergranular network and internetwork.
Authors: Kučera, A.; Curdt, W.; Fludra, A.; Rybák, J.; Wöhl, H.
1999joso.proc..149K Altcode:
Study of the variability of the quiet solar atmosphere covering as
large as possible range of the temperatures using both the 2D imaging
and 1D spectra was the aim of SOHO JOP 78 observations. Supergranular
cells were the objects of the authors' main interest. This programme is
based on the cooperation of several SOHO instruments (SUMER, CDS, MDI,
EIT) and TRACE. Justification of the JOP, cooperation of instruments
and specially arranged measurements for the post-facto coalignment of
data from different instruments are described in this paper.
---------------------------------------------------------
Title: Correlation of Velocity Fields at Different Heights in the
Solar Photosphere
Authors: Kucera, A.; Rybák, J.; Wöhl, H.
1999ASSL..239..219K Altcode: 1999msa..proc..219K
A simple experimental method for comparison of the line formation
heights in the solar photosphere is presented. Several Fe I lines are
used to test the method.
---------------------------------------------------------
Title: Heights of formation of FeI photospheric lines
Authors: Kucera, A.; Balthasar, H.; Rybak, J.; Woehl, H.
1998A&A...332.1069K Altcode:
The determination of the location of spectral line-forming layers
by means of line-depression contribution functions is checked by
observational tests. The method is based on the assumption that the
Doppler velocities derived from line bisectors at a given position in
the profile of a spectral line are related to the actual bulk velocity
at a particular height in the atmosphere. For a set of six magnetically
sensitive and non-sensitive Fe I lines (543.45, 557.61, 630.15, 630.25,
649.50, 649.45 nm) the fluctuations of Doppler velocities along the slit
of the spectrograph were determined at various Delta lambda from the
line centers i.e. at various heights in the photosphere. Correlations
of fluctuations allow us to find those parts in line profiles which
are formed at identical heights in the photosphere. These experimental
results are compared with theoretical estimates based on line depression
contribution functions. The agreement is good and best results are found
for nonmagnetic strong, but still unsaturated lines. The results support
the hypothesis that it is possible to ascribe a single height point
in the solar atmosphere to a given position in a spectral line profile.
---------------------------------------------------------
Title: Oscillations in Chromosphere and Transition Region Based on
SUMER Measurements
Authors: Kucera, A.; Curdt, W.; Rybák, J.; Schühle, U.; Wöhl, H.
1998ASPC..155..351K Altcode: 1998sasp.conf..351K
No abstract at ADS
---------------------------------------------------------
Title: Behaviour of solar active prominence
Authors: Kučera, A.; Rybák, J.; Saniga, M.
1998PAICz..88..232K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Measurement of rotational characteristics of sunspots and
surrounding photospheric plasma.
Authors: Kučera, A.; Rybák, J.; Wöhl, H.
1997joso.proc...68K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Investigation of the Dynamics of Chromosphere and Photosphere
from Spectra Obtained by Parallel Observations using SUMER on SOHO
and the VTT on Tenerife
Authors: Curdt, W.; Kucera, A.; Rybak, J.; Schuhle, U.; Wohl, H.
1997ASPC..118..322C Altcode: 1997fasp.conf..322C
This is a preliminary report about parallel observations of
chromospheric and photospheric spectra in the ultraviolet and visible
spectral regions using SUMER on SOHO and the VTT on Tenerife performed
begin of September 1996. The aim is to search for relations of vertical
velocity patterns in the upper photosphere and chromosphere in the
solar disk center. In addition temporal changes in these parts of the
solar atmosphere are investigated.
---------------------------------------------------------
Title: Dynamical Properties of the Chromosphere and Transition Region
in the Supergranular Network: What Precision of the Spectral Line
Characteristics Can be Reached?
Authors: Curdt, W.; Kucera, A.; Rybák, J.; Schühle, U.; Wöhl, H.
1997ESASP.404..307C Altcode: 1997cswn.conf..307C
No abstract at ADS
---------------------------------------------------------
Title: Observations of Fe I lines in the quiet solar photosphere.
Authors: Kucera, A.; Rybak, J.; Woehl, H.
1995A&A...298..917K Altcode:
We investigate three sets of spectra with high spatial and spectral
resolution. Each set consists of four spectra taken simultaneously
with the Vacuum Tower Telescope at Izana, Tenerife. The main spectral
characteristics (continuum intensity I_c_; full width at half
maximum FWHM; residual intensity I_o_) were computed for 5 magnetic
and non-magnetic Fe I lines (5434.543 A, 5576.099 A, 6301.497 A,
6302.499 A, 6494.994 A). Our results allow a diagnosis of the solar
atmosphere in the vertical (two main levels of line formation)
and horizontal directions (71 arcseconds). The spectra cover both
interior parts of supergranular cells (purely quiet regions, PQR) and
cell boundaries (moderate active regions, MAR). The main results are:
(1) We find a different continuum intensity distribution for PQRs
and MARs, which reflects the existence of different patterns in these
regions. The difference is also evident in the rms residual intensity
fluctuation. (2) A significant minimum of the residual intensity
fluctuations (δI_o_/I_c_)_rms_ occurs at a height of about 300km. (3)
At all heights of the PQRs the line widths FWHM in the intergranular
lanes are larger than the mean line width; those in the granules
are smaller. This variation of the FWHM is influenced by a magnetic
effect near the centres of the intergranular lanes (reduced FWHM),
and by the effect of convection in granules (enhanced FWHM). (4)
The correlation <I_c_, I_o_> reverses its sign at a height of
about 250km. The anticorrelation in the range 300-500km indicates a
non-convective structure, different from the photospheric granular
pattern found earlier.
---------------------------------------------------------
Title: Contributions of the Astronomical Observatory Skalnate Pleso,
Volume 25
Authors: Zverko, Juraj; Antalova, Anna; Svoren, Jan; Chochol, Drahomir;
Kucera, Ales; Porubcan, Vladimir
1995STIN...9624442Z Altcode:
Topics addressed include astrometry of minor planets, solar magnetic
sectors and spatial distribution of LDE-type flares, radar observations
of the Perseid meteor shower, periodic variations in the light
curves of symbiotic stars, photometry of symbiotic stars, even-odd
solar-cycle differences of corona brightness, solar eclipses, and index
of cosmic ray fluctuations at neutron monitor energies. Also addressed
is stratification of chromium abundance in CP-stars alpha<SUP>2</SUP>
Canum Venaticorum, epsilon Ursae Majoris, Sirius and Vega.
---------------------------------------------------------
Title: A Solar Plage Model
Authors: Kucera, A.; Baranovsky, E. A.
1994IAUS..154...29K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: JOSO Workshop: Instrumentation for magnetic field measurements
Authors: Kucera, A.
1994imfm.conf.....K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mass Ejections from Chromosphere to Corona: Results from a
Spectral Analysis
Authors: Kučera, A.; Rybák, J.; Minaroviech, M.
1994emsp.conf..147K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Magnetic and nonmagnetic line profiles in solar quiet and
active regions
Authors: Kučera, A.; Rybák, J.; Wöhl, H.
1994smf..conf..291K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: H-Alpha Morphology of Gamma-Flares
Authors: Kucera, A.; Antalová, A.
1994step.conf..151K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Joint Organization for Solar Observations (24th meeting).
Authors: Kucera, A.
1993Kozmo..24...23K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Hot mass transport in the solar active prominence
Authors: Kucera, A.; Saniga, M.; Rybak, J.
1992AIPC..267..160K Altcode: 1992ecsa.work..160K
On October 16, 1990, a remarkable active prominence was observed,
in Hα line, during 113 minutes. The time gap between successive
profile recordings was 20 seconds and 339 profiles have been recorded
together. We focused our attention on Doppler shift measurements as
well as on significant changes in the prominence intensity. We also
give a possible explanation of a sudden increment in the intensity of
Hα line in dependence on the fact if the whole profile originates in
one particular place in the prominence or if it is a superposition of
the radiation incident from two different, physically unrelated parts
of the prominence.
---------------------------------------------------------
Title: Height-Dependent Solar Plage Temperature Distribution (With
3 Figures)
Authors: Kucera, A.; Scherbakova, Z.; Baranovsky, E.
1991mcch.conf..109K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The horizontal solar telescope with spectrograph at Stará
Lesná Observatory
Authors: Kucera, A.; Rybak, J.; Minarovjech, M.; Novocky, D.;
Saniga, M.
1990Ap&SS.171..279K Altcode:
The construction and the optical design as well as the controlling
electronic device and the spectrum recording of the new horizontal
solar telescope with the spectrograph of the Astronomical Institute of
Slovak Academy of Sciences are described. Also some of its adjustments
and improvements are briefly mentioned.
---------------------------------------------------------
Title: The H, K and IR triplet of Ca II in plages.
Authors: Baranovskij, Eh. A.; Kuchera, A.; Kučera, A.; Shcherbakova,
Z. A.
1987IzKry..77....3B Altcode:
The observed profiles of Ca II lines H, K, λ8498, λ8542, λ8662 are
obtained and the model chromospheres are derived for plages of different
brightness. The calculations involve the program of non-LTE spectra
analysis. The density in the bright plages is of an order of 2 higher
than that of the undisturbed chromosphere. The models of weak plages
do not differ significantly from the undisturbed model chromosphere.
---------------------------------------------------------
Title: Can small-scale bipolar structures originate in the solar
atmosphere ?
Authors: Saniga, M.; Kučera, A.; Novocký, D.; Rybák, J.
1986CoSka..15..683S Altcode:
Using the formalism of the magnetohydrodynamics shock waves the simple
model of the origin of small-scale bipolar structures in a magnetized
plasma is outlined. It is shown that there are regions in the atmosphere
of the Sun where such object can naturally occur. Properties of these
structures and their typical dimension are examined.
---------------------------------------------------------
Title: Relationships of a growing magnetic flux region to flares
Authors: Martin, S. F.; Bentley, R. D.; Schadee, A.; Antalova, A.;
Kucera, A.; Dezső, L.; Gesztelyi, L.; Harvey, K. L.; Jones, H.;
Livi, S. H. B.; Wang, J.
1984AdSpR...4g..61M Altcode: 1984AdSpR...4...61M
Some sites for solar flares are known to develop where new magnetic
flux emerges and becomes abutted against opposite polarity pre-existing
magnetic flux (review by Galzauskas/1/). We have identified and analyzed
the evolution of such flare sites at the boundaries of a major new and
growing magnetic flux region within a complex of active regions, Hale
No. 16918. This analysis was done as a part of a continuing study of the
circumstances associated with flares in Hale Region 16918, which was
designated as an FBS target during the interval 18 - 23 June 1980. We
studied the initiation and development of both major and minor flares in
Hα images in relation to the identified potential flare sites at the
boundaries of the growing flux region and to the general development
of the new flux. This study lead to our recognition of a spectrum of
possible relationships of growing flux regions to flares as follows:
(1) intimate interaction with adjacent old flux - flare sites centered
at new/old flux boundary, (2) forced or “intimidated” interaction
in which new flux pushes old field having lower flux density towards a
neighboring old polarity inversion line where a flare then takes place,
(3) “influential” interaction - magnetic lines of force over an old
polarity inversion line, typically containing a filament, reconnect to
the new emerging flux; a flare occurs with erupting filament when the
magnetic field overlying the filament becomes too weak to prevent its
eruption, (4) inconsequential interaction - new flux region is too small
or has wrong orientation for creating flare conditions, (5) incidental -
flare occurs without any significant relationship to new flux regions.
---------------------------------------------------------
Title: The Crimean Astrophysical Observatory.
Authors: Kučera, A.
1984Kozmo..15...10K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Irregular Rotation of the Main Sunspot in Active Region Hale
17 570 of 5-13 April 1981
Authors: Kucera, A.
1982BAICz..33..345K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Emerging magnetic flux, flares and filaments - FBS interval
16-23 June 1980
Authors: Martin, S. F.; Dezso, L.; Antalova, A.; Kucera, A.; Harvey,
K. L.
1982AdSpR...2k..39M Altcode: 1982AdSpR...2...39M
17 emerging magnetic flux regions with arch filaments related to
new sunspots were identified in Hale Active Region No. 16918 during
the 7 day interval from 16-22 June. Most of the new flux regions
were clustered around the filament channel between the old opposite
polarity fields as were most of the flares. The two largest regions of
new magnetic flux and a few of the smaller flux regions developed very
near the end points of filaments. This suggests that the emergence of
flux in existing active regions might be non-random in position along
a filament channel as well as in distance from a filament channel. <P
/>We have analyzed the positions of 88 flares to date during about
half of each day. We find that slightly more than half (50%) of the
flares, irrespective of their size, are centered within the new flux
regions. About 1/5 (20%) were centered on the border between the new
flux and the adjacent older magnetic field. Less than 1/3 occurred
outside of the newly emerging flux regions but in many cases were very
close to the newly emerging flux. We conclude that at least 2/3 of
the flares are intimately related to the emerging flux regions while
the remaining 1/3 might be either indirectly related or unrelated to
the emerging flux.
---------------------------------------------------------
Title: Search for the Period of the Binary Shell Star V505 Monocerotis
Authors: Chochol, D.; Kucera, A.
1981IBVS.1998....1C Altcode:
No abstract at ADS