34 research outputs found
Development of the Burst and Transient Source Experiment (BATSE)
The Burst and Transient Source Experiment (BATSE), one of four instruments on the Gamma Ray Observatory, consists of eight identical detector modules mounted on the corners of the spacecraft. Developed at MSFC, BATSE is the most sensitive gamma ray burst detector flown to date. Details of the assembly and test phase of the flight hardware development are presented. Results and descriptions of calibrations performed at MSFC, TRW, and KSC are documented extensively. With the presentation of each calibration results, the reader is provided with the means to access raw calibration data for further review or analysis
The Effects of Pure Density Evolution on the Brightness Distribution of Cosmological Gammy-Ray Bursts
In this work, we explore the effects of burst rate denisty evolution on the observed brightness distribution of cosmological gamma-ray bursts. Although the brightness distribution of gamma-ray bursts observed by the BATSE experiment has been shown to be consisitent with a nonevoloving soruce population observed to redshifts of order unity, evolution of some form is likely to be present in the gamma-ray bursts. Additionally nonevolving models place significant constraints on the range of observed burst luminosities, which are relaxed if evolution of the burst population is present. In this paper, three analytic forms of density evolution are examined. In general, forms of evolution with densities that increase montonically with redshift require that the BATSE data correspond to burst at larger redshifts, or to incorporate a wider range of burst luminosities, or both. Independent estimates of the maximum observed redshift in the BATSE data and/or the range of luminosity from which are large fraction of the observed burts are drawn therefore allow for constraints to be placed on the amount of evolution that may be present in the burst population. Specifically, if recent measurements obtained from analysis of the BATSES duration distribution of the actiona limiting redshift in the BATSE data at Zlim = 2 are correst, the BATSE N(P) distribution is a A=0 universe is inconsistent at a level of ~3 σ with the nonevolving gamma-ray bursts and some for of evolution in the population is required. The sense of this required source evolution is to provide a higher desnisty, larger luminosities, or both with increasing redshift
The effects of pure density evolution on the brightness distribution of cosmological gamma-ray bursts
In this work, we explore the effects of burst rate density evolution on the observed brightness distribution of cosmological gamma-ray bursts. Although the brightness distribution of gamma-ray bursts observed by the BATSE experiment has been shown to be consistent with a nonevolving source population observed to redshifts of order unity, evolution of some form is likely to be present in the gamma-ray bursts. Additionally, nonevolving models place significant constraints on the range of observed burst luminosities, which are relaxed if evolution of the burst population is present. In this paper, three analytic forms of density evolution are examined. In general, forms of evolution with densities that increase monotonically with redshift require that the BATSE data correspond to bursts at larger redshifts, or to incorporate a wider range of burst luminosities, or both. Independent estimates of the maximum observed redshift in the BATSE data and/or the range of luminosity from which a large fraction of the observed bursts are drawn therefore allow for constraints to be placed on the amount of evolution that may be present in the burst population. Specifically, if recent measurements obtained from analysis of the BATSE duration distribution of the actual limiting redshift in the BATSE data at z(sub lim) = 2 are correct, the BATSE N(P) distribution in a Lambda = 0 universe is inconsistent at a level of approximately 3 alpha with nonevolving gamma-ray bursts and some form of evolution in the population is required. The sense of this required source evolution is to provide a higher density, larger luminosities, or both with increasing redshift
On the association of terrestrial gamma-ray bursts with lightning and implications for sprites
Includes bibliographical references (page [1020]).Measurements of ELF/VLF radio atmospherics (sferics) at Palmer Station, Antarctica, provide evidence of active thunderstorms near the inferred source regions of two different gamma-ray bursts of terrestrial origin [Fishman et al., 1994]. In one case, a relatively intense sferic occurring within ±1.5 ms of the time of the gamma-ray burst provides the first indication of a direct association of this burst with a lightning discharge. This sferic and many others launched by positive cloud-to-ground (CG) discharges and observed at Palmer during the periods studied exhibit 'slow tail' waveforms, indicative of continuing currents in the causative lightning discharges. The slow tails of these sferics are similar to those of sferics originating in positive CG discharges that are associated with sprites
Null Result in Gamma-Ray Burst Lensed Echo Search
We have searched for gravitational-lens induced echoes between gamma-ray
bursts (GRBs) in NASA's orbiting {\it Compton} Gamma Ray Observatory's Burst
and Transient Source Experiment (BATSE) data. The search was conducted in two
phases. In the first phase we compared all GRBs in a brightness complete sample
of the first 260 GRBs with recorded angular positions having at least 5 \%
chance of being coincident from their combined positional error. In the second
phase, we compared all GRB light curves of the first 611 GRBs with recorded
angular positions having at least 55 \% chance of being coincident from their
combined positional error. No unambiguous gravitational lens candidate pairs
were found in either phase, although a ``library of close calls" was
accumulated for future reference. This result neither excludes nor
significantly constrains a cosmological origin for GRBs.Comment: in press: ApJ, Plain TeX, 14 pages, 17 figures (available by FAX
The detector response matrices of the burst and transient source experiment (BATSE) on the Compton Gamma Ray Observatory
The detector response matrices for the Burst And Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory (CGRO) are described, including their creation and operation in data analysis. These response matrices are a detailed abstract representation of the gamma-ray detectors' operating characteristics that are needed for data analysis. They are constructed from an extensive set of calibration data coupled with a complex geometry electromagnetic cascade Monte Carlo simulation code. The calibration tests and simulation algorithm optimization are described. The characteristics of the BATSE detectors in the spacecraft environment are also described
Preliminary calibration results for the BATSE instrument on CGRO
Preliminary results pertaining to spectral reconstruction using Burst and Transient Source (BATSE) Large Area Detector measurements of solar flares are presented. The solar flare measurements are currently being used to fine tune the calibration of our data analysis software. The current status of the stability of spectral analysis, given the systematic errors present in burst location, are given. A brief description is given of enhancements to the input data for the atmospheric scattering algorithm that will be implemented in the data analysis software
Testing the Dipole and Quadrupole Moments of Galactic Models
If gamma-ray bursts originate in the Galaxy, at some level there should be a
galactic pattern in their distribution on the sky. We test published galactic
models by comparing their dipole and quadrupole moments with the moments of the
BATSE 3B catalog. While many models have moments that are too large, several
models are in acceptable or good agreement with the data.Comment: 5 pages, LaTex using Revtex macro aipbook.sty and psfig. To appear in
the Proceedings of the 3rd Huntsville Symposium on Gamma-Ray Bursts, AIP,
eds. C. Kouveliotou, M. S. Briggs, G. J. Fishma
The Locations of Gamma-Ray Bursts Measured by COMPTEL
The COMPTEL instrument on the Compton Gamma Ray Observatory is used to
measure the locations of gamma-ray bursts through direct imaging of MeV
photons. In a comprehensive search, we have detected and localized 29 bursts
observed between 1991 April 19 and 1995 May 31. The average location accuracy
of these events is 1.25\arcdeg (1), including a systematic error of
\sim0.5\arcdeg, which is verified through comparison with Interplanetary
Network (IPN) timing annuli. The combination of COMPTEL and IPN measurements
results in locations for 26 of the bursts with an average ``error box'' area of
only 0.3 deg (1). We find that the angular distribution of
COMPTEL burst locations is consistent with large-scale isotropy and that there
is no statistically significant evidence of small-angle auto-correlations. We
conclude that there is no compelling evidence for burst repetition since no
more than two of the events (or 7% of the 29 bursts) could possibly have
come from the same source. We also find that there is no significant
correlation between the burst locations and either Abell clusters of galaxies
or radio-quiet quasars. Agreement between individual COMPTEL locations and IPN
annuli places a lower limit of 100~AU (95% confidence) on the distance to
the stronger bursts.Comment: Accepted for publication in the Astrophysical Journal, 1998 Jan. 1,
Vol. 492. 33 pages, 9 figures, 5 table