Previous abstract Next abstract

Session 48 - Gamma Rays & X-ray Instrumentation.
Display session, Thursday, January 08
Exhibit Hall,

[48.01] MeV Measurements of Gamma-Ray Bursts by CGRO-COMPTEL

A. Connors, S. Kappadath, M. McConnell, J. M. Ryan, C. A. Young (Space Science Center, U. New Hampshire), K. Bennett, O. R. Williams, C. Winkler (Astrophysics Division, ESTEC), W. Collmar, V. Schönfelder, M. Varendorff (MPI fur Extraterrestrische Physik), W. Hermsen, L. Kuiper (SRON-Utrecht), R. M. Kippen (C.S.P.A.R., U. Alabama)

Since the launch of the Compton Gamma--Ray Observatory in April 1991, the imaging COMPTEL telescope has accumulated positions and 0.75--30 MeV spectra of thirty-three gamma-ray bursts within its Pi sr field of view. BATSE (and Konus) data have shown some evidence for two classes of burst emission, based on presence (HE) or lack (NHE) of flux >300 keV (Pendleton et al. 1996 and references therein). Piran and Naryan (1996) suggest MeV--bright bursts may be undercounted by BATSE. COMPTEL preferentially measures this potentially interesting subclass. We will present the latest spatial, spectral, and temporal distributions of these events. These include the spectra of GRB 961212 and the soft faint burst GRB 970807. Like most bursts observed by COMPTEL, their spectra appear to be well--represented by power-law models with photon indexes \sim2.1 and \sim3.0, respectively. Also, COMPTEL broadcasts the 1-2 degree localizations within 8-15 minutes of burst onset, via ongoing collaboration with BACODINE/GCN network. The COMPTEL positions of two of the most recent bursts, GRB 961212 and GRB 970807, were relayed to a global network of multiwavelength observers in 15 and 45 minutes, respectively. In the future, we plan to upgrade the system, potentially allowing us to broadcast 1-2 degree localizations within a few minutes of burst onset. Such rapid response raises the possibility of multi-wavelength observations of particularly bright, well-suited, bursts, while the high energy emission is still underway.

If you would like more information about this abstract, please follow the link to This link was provided by the author. When you follow it, you will leave the the Web space for this meeting; to return, you should use the Back button on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract:

Program listing for Thursday