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We present an extended cross-calibration study between the Fermi Gamma-Ray Burst Monitor (GBM) and the INTEGRAL Soft Gamma-Ray Imager ISGRI. A previous sample contained 4 GRBs; GRB081226B; GRB090107B; GRB090625B and GRB090704. A long burst detected by both instruments, GRB090817, provides us with the opportunity to further test the agreement between the previous sample and the new data. GRB090817 contains significant telemetry gaps in the ISGRI data set and methods were devised to account for these gaps. The combined datasets from both instruments for GRB090817 were fit with 3 separate spectral models-a Power Law (PL), Cut-Off Power Law (COPL) and a Band model. The best fit joint spectral model is shown for the time averaged and time resolved joint spectral fits. As a measure of relative flux between the two instruments, a normalisation constant was calculated from the joint spectral fitting. [ABSTRACT FROM AUTHOR]

It has been demonstrated that the colors of optical afterglows (OAs) of GRBs are unique and almost identical for most of these events detected and analyzed in detail so far. This enables conclusions toward physics of the source and physics of the source environment. In addition, OAs can be identified on CCD images taken at one time but in various filters. In this study, we compare the color behaviour of OAs of GRBs with those of other extragalactic objects. We will show that not only the physical processes involved as well as environment of the objects can be studied this way but also a classification of objects of various types is possible with color photometric data provided e.g. by deep CCD searches and experiments. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We analyze GRB 030501 using combined available data from INTEGRAL and RHESSI. We try to decompose the lightcurve into elementary peaks and show the correlation between lightcurve and spectral behavior of the burst within the framework of the fireball model. First we try to generate synthetic lightcurves and spectra and compare it with real bursts. We suggest non-constant secondary induced magnetic field. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

We report on the search for positional and temporal correlations between gamma-ray bursts (GRBs) in the CGRO BATSE catalog and the supernovae (SNe) detected during the BATSE era (1991–2000). By making use of innovative procedures we have carried out a statistical analysis of the results. We have checked if the possibly correlated objects differ in physical properties from the rest of the GRB/SN sample. Although at least two GRB-SN coincidences are known, our preliminary results do not indicate significant correlations between GRBs and supernovae which are presently detected by SN searches, but provide new insights into correlations based on physical properties of GRB and SN samples. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

BART is a small remote controlled robotic CCD telescope, devoted to rapid observation of prompt gamma ray burst transients. During its operation since early 2001, it had three prompt observations with world-competitive response time. The constraints to object magnitude were estimated and published in GCN circulars. Telescope is located in Astronomical Institute of the Czech Academy of Sciences in Ondrˇejov. This poster describes its new control system, named RTS2, which has been in service since February 2003. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

GRB 080723B was a long and intense gamma-ray burst detected and localized by the INTEGRAL satellite featuring combined observations from both main instruments on-board, IBIS and SPI. The burst was composed of several well separated peaks, allowing the time-resolved spectral evolution to be studied. IBIS and SPI spectra and light curves for the prompt emission are presented. [ABSTRACT FROM AUTHOR]