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RHESSIGRB - RHESSI Gamma-Ray Burst Catalog

 HEASARC
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Overview

The authors have studied statistically with respect to duration and hardness ratio a sample of 427 gamma-ray bursts (GRBs) measured by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) satellite, a NASA Small Explorer satellite designed to study hard X-rays and gamma-rays from solar flares (Lin et al., 2002, Sol. Phys., 210, 3). Standard statistical tests were used, such as chi2, F-test, and the maximum likelihood ratio test, to compare the number of GRB groups in the RHESSI database with that of the BATSE database.

The authors used the RHESSI GRB Catalog (Wigger et al., 2008, http://grb.web.psi.ch/) and the Cosmic Burst List (Hurley, 2008, http://www.ssl.berkeley.edu/ipn3/masterli.html) to detect 487 GRBs in the RHESSI data over the time period between 2002 February 14 and 2008 April 25. For a deeper analysis, they chose a subset of 427 GRBs with data with a signal-to-noise ratio higher than 6. This table contains this subset.

Catalog Bibcode

2009A&A...498..399R

References

Search for gamma-ray burst classes with the RHESSI satellite.
    Ripa J., Meszaros A., Wigger C., Huja D., Hudec R., Hajdas W.
   <Astron. Astrophys., 498, 399-406 (2009)>
   =2009A&A...498..399R

Provenance

This HEASARC table was created in March 2010 based on CDS catalog J/A+A/498/399 file table7.dat.

Parameters

Name
The gamma-ray burst designation. The GRB name is formed by prexix 'GRB' followed by the date of the detection, in the form YYDDMM. e.g., 'GRB 960802'. In case of more than one burst in a day, a letter A, B, C is added to distinguish the specific bursts. These letters after the GRB names are internal and do not have to be in accordance with e.g. GCN GRB names.

Time
The GRB peak time (UTC). This was given to a precision of 0.001 seconds in the original table.

T90
The T_90 duration of the GRB, in seconds. T_90 is defined as the time interval during which the cumulative counts in the GRB increase from 5% to 95% above the background.

T90_Error
The RMS uncertainty in T90, in seconds.

Time_Resolution
The time resolution of the derived GRB light curve, in seconds.

Hardness_Ratio
The hardness ratio HR of the GRB, defined as the ratio of the two fluences F in two different energy bands and integrated over the time interval T90. For the RHESSI data set, the authors used the energy bands 25 - 120 keV and 120 - 1500 keV, i.e., HR = F(120-1500 keV)/F(25-120 keV). The published table caption indicates this parameter as being "log H" but, as the CDS notes, the hardness ratios being in the range from -1 to +1, they cannot be expressed in a log scale.

Hardness_Ratio_Error
The RMS uncertainty in the hardness ratio HR.

Contact Person

Questions regarding the RHESSIGRB database table can be addressed to the HEASARC User Hotline.

A service of the Astrophysics Science Division at NASA/GSFC and the High Energy Astrophysics Division of the Smithsonian Astrophysics Observatory (SAO)

Page Author: Browse Software Development Team
Last Modified: 19-Mar-2010