arXiv subjects

G. N. Pendleton

Publications and source records attributed to G. N. Pendleton.

21 records · Page 2Linked to original sources

arXiv1995

BATSE Gamma-Ray Burst Line Search: III. Line Detectability

We evaluate the ability of the BATSE spectroscopy detectors to detect the absorption lines observed by Ginga in gamma ray burst spectra. We find that BATSE can detect the 20.6 keV line in the S1 segment of GB870303 with a detection probability of ~1/4 in nearly normally incident bursts, with the probability dropping off to nearly 0 at a burst angle of 50 degrees; the lines at 19.4 and 38.8 keV lines in GB880205 have a high detection probability in BATSE up to burst angles of 75 degrees. In addition, we calculate detection probabilities for these two line types as a function of signal-to-noise ratio and burst angle for use in detailed comparisons between BATSE and Ginga. Finally, we consider the probability averaged over the sky of detecting a line feature with the actual array of BATSE detectors on CGRO.

astro-ph↗

arXiv1995

Time Dependent Clustering Analysis of the Second BATSE Gamma-Ray Burst Catalog

A time dependent two-point correlation-function analysis of the BATSE 2B catalog finds no evidence of burst repetition. As part of this analysis, we discuss the effects of sky exposure on the observability of burst repetition and present the equation describing the signature of burst repetition in the data. For a model of all burst repetition from a source occurring in less than five days we derive upper limits on the number of bursts in the catalog from repeaters and model-dependent upper limits on the fraction of burst sources that produce multiple outbursts.

astro-ph↗

arXiv1994

BATSE Observations of Gamma-Ray Burst Spectra. II. Peak Energy Evolution in Bright, Long Bursts -

We investigate spectral evolution in 37 bright, long gamma-ray bursts observed with the BATSE Spectroscopy Detectors. High resolution spectra are characterized by the energy of the peak of \nfn~and the evolution of this quantity is examined relative to the emission intensity. In most cases it is found that this peak energy either rises with or slightly precedes major intensity increases and softens for the remainder of the pulse. Inter-pulse emission is generally harder early in the burst. For bursts with multiple intensity pulses, later spikes tend to be softer than earlier ones indicating that the energy of the peak of \nfn~is bounded by an envelope which decays with time. Evidence is found that bursts in which the bulk of the flux comes well after the event which triggers the instrument tend to show less peak energy variability and are not as hard as several bursts in which the emission occurs promptly after the trigger. Several recently proposed burst models are examined in light of these results and no qualitative conflicts with the observations presented here are found.

astro-ph↗