G. J. Fishman

Marshall Space Flight Center

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W. S. Pačiesas

Universities Space Research Association

C. Meegan

University of Alabama in Huntsville

B. A. Harmon

Louisiana State University

Robert Wilson

Stanford University

R. B. Wilson

Marshall Space Flight Center

C. Kouveliotou

George Washington University

G. N. Pendleton

Dynetics (United States)

M. S. Briggs

University of Alabama in Huntsville

K. Hurley

University of California, Berkeley

C. A. Wilson

Ministry Of Health

Cooperative Institutions

Goddard Space Flight Center

105

Marshall Space Flight Center

Stanford University

Kavli Institute for Particle Astrophysics and Cosmology

California Institute of Technology

SLAC National Accelerator Laboratory

Centre National de la Recherche Scientifique

Universities Space Research Association

University of Alabama in Huntsville

Max Planck Society

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Search for deterministic pulse trends in gamma ray burst temporal profiles

AIP conference proceedings (1991)

J. P. Norris C. Kouveliotou G. J. Fishman C. Meegan R. B. Wilson

Most cosmic gamma‐ray burst temporal profiles appear to be comprised of several individual pulses, many of which overlap. It is advantageous to deconvolve the temporal structures into their constituent pulses, and thereby investigate the shape, intensity and temporal distributions of the pulses as a function of energy. Such fundamental pulse descriptors would provide constraints for theoretical modeling of the burst emission process, such as indications of source size, optical depth and geometry as a function of time. We have developed a deconvolution algorithm which treats sequences of pulse shapes that change deterministically. The algorithm, a generalization of autoregressive techniques, has been applied to a few bright bursts observed by BATSE. Results indicate that, even within short intervals, constituent pulses are not self‐similarly shaped, nor do pulse shapes evolve in a simple manner throughout a burst. Hence, the direction of our future work on pulse deconvolution will focus on analysis methods which allow pulse shape to vary.

10.1063/1.42797

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Evidence for Highly Inhomogeneous mm-Wave Sources During the Impulsive Flare of May 9, 1991

Astronomy and Astrophysics (1997)

R. Herrmann A. Magun P. Kaufmann E. Correia J. E. R. Costa

In this paper multiwavelength observations of an impulsive flare of May 9, 1991 are presented. This event was observed with the 48 GHz multibeam focal array used at the Itapetinga radio telescope, the microwave patrol telescopes at Bem and the BATSE high time resolution hard X-ray spectrometer on board CGRO. While spatially unresolved low sensitivity observations show two major impulsive peaks, the mm-wave observations with the ability of spatially high resolved tracking of the emission centroids suggest a primarily bipolar source configuration. For the first time two mm-wave sources with a spacing below the HPBW could be separated with the multibeam technique. The general features of the observations are explained as emission of partially trapped electrons. Furthermore we present evidence for highly inhomogeneous substructures within one of the two mm-wave sources for which the positional scatter of the emission center, within 2s, is less than 2.

Flare

Solar flare

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X-Ray Nova 1994 in Scorpius

International Astronomical Union Circular (1995)

S. Sazonov R. Sunyaev S. N. Zhang B. A. Harmon W. S. Pačiesas

Nova (rocket)

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The hard X-ray pulse profile of the transient source A0535+26

The Astrophysical Journal (1977)

G. J. Fishman Jr. Watts J. W.

view Abstract Citations (15) References (9) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The hard X-ray pulse profile of the transient source A 0535+26. Fishman, G. J. ; Watts, J. W., Jr. Abstract Measurements of the 104 sec pulse profile of A0535+26 at energies near 50 keV are reported. The data were obtained with a balloon-borne detector system which was launched on May 22, 1975 with the objective to observe transient or periodic emissions from X-ray or gamma-ray sources. The presence of the source was detected by a superposed epoch analysis. The pulse profile of A0535+26 in two energy channels is presented in a graph. Publication: The Astrophysical Journal Pub Date: February 1977 DOI: 10.1086/155037 Bibcode: 1977ApJ...212..211F Keywords: Balloon Sounding; Pulsed Radiation; Radiant Flux Density; X Ray Astronomy; Astronomical Spectroscopy; Balloon-Borne Instruments; Periodic Variations; Radiation Detectors; Scintillation Counters; Spectral Energy Distribution; X Ray Spectra; Astrophysics full text sources ADS | data products SIMBAD (1)

10.1086/155037

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Solar response of the BATSE instrument on the gamma-ray observatory

G. J. Fishman C. A. Meegan T. A. Parnell Robert Wilson W. S. Pačiesas

The Burst and Transient Source Experiment (BATSE) on board the gamma ray observatory (GRO) aims at comprehensive observations of time profiles, spectra, and locations of high-energy transient sources. The mysterious cosmic gamma ray bursts provided the main motivation for the observations, but BATSE will make excellent observations of many classes of sources, and in particular solar flares. The solar response of BATSE, as inferred from its design parameters, is analyzed for two purposes: the optimization of the solar observations themselves, and the characterization of the solar effects on ordinary nonsolar observations.

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Transient (computer programming)

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Search for 511 keV line emission from the galactic center with BATSE.

Bulletin of the American Astronomical Society (1992)

E. G. Chipman M. Leventhal C. A. Gehrels J. Tueller G. J. Fishman

Line (geometry)

Center (category theory)

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Citations (11)

Hard X-Ray Observations With a Large-Area Balloon-Borne Detector Array.

Bulletin of the American Astronomical Society (1977)

C. Meegan G. J. Fishman

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Measuring the Super-Hot Component with the BATSE Spectroscopy Detectors

AAS (1992)

R. A. Schwartz G. J. Fishman C. Meegan Richard B. Wilson W. S. Pačiesas

Component (thermodynamics)

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BATSE observations of GRO J0422+32, an X-ray nova in Perseus.

Bulletin of the American Astronomical Society (1992)

W. S. Pačiesas G. N. Pendleton M. S. Briggs B. A. Harmon G. J. Fishman

Nova (rocket)

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Constraints on galactic gamma-ray bursts models from BATSE angular and intensity distributions

AIP conference proceedings (1993)

Jon Hakkila C. Meegan G. J. Fishman Robert Wilson M. N. Brock

The paradigm that gamma‐ray bursts originate from Galactic populations is studied in detail using the BATSE angular and intensity distributions. Monte Carlo models of gamma‐ray burst spatial distributions and luminosity functions are created, then folded through mathematical models of BATSE selection effects. The BATSE Burst Catalog and the Monte Carlo Burst Catalogs are analyzed using modified statistical homogeneity and isotropy tests. Numerous catalog results are studied so that errors can be established.Analysis of BATSE angular and intensity distributions greatly constrains origins and luminosities of bursts. No single population of Galactic Disk, Halo, or Local Spiral Arm sources satisfactorily explains BATSE observations (and burst luminosity functions are of secondary importance when considering such models). One family of models still satisfying BATSE data is comprised of sources in a spherical Galactic Corona. Coronal models are limited to small ranges of burst luminosity and core radius. Multiple‐population models work only if (1) the primary population accounts for the general isotropy and inhomogeneity seem by BATSE, and (2) secondary populations either have characteristics similar to the primary population or contain small numbers.

10.1063/1.44255

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Citations (1)