BIB-VERSION:: AST-PP-v1.0
ID:: epreps.stsci//prep1205
ENTRY:: March 9, 1998
TITLE:: The Gamma Ray Bursts GRB970228 and GRB970508: What have we learnt?
SUBTITLE::
AUTHOR:: Livio, Mario (1)
AUTHOR:: Sahu, Kailash C. (1)
AUTHOR:: Petro, Larry (1)
AUTHOR:: Fruchter, Andrew (1)
AUTHOR:: Pian, Elena (2)
AUTHOR:: Macchetto, F. Duccio (1)
AUTHOR:: Paradijs, Jan van (3,4)
AUTHOR:: Kouveliotou, Chryssa (5)
AUTHOR:: Groot, Paul J. (3)
AUTHOR:: Galama, Titus J. (3)
AFFIL:: (1) Space Telescope Science Institute 3700 San Martin Drive Baltimore, MD 21218 USA
AFFIL:: (2) Instituto di Technologie e Studio delle Radiazioni Extraterrestri C.N.R., Via Gobetti 101, I-40129 Bologna, Italy
AFFIL:: (3) Astronomical Institute "Anton Pannekoek", University of Amsterdam, & Center for High Energy Astrophysics, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
AFFIL:: (4) Physics Department University of Alabama in Huntsville, Huntsville, AL 35899, USA
AFFIL:: (5) Universities Space Research Association, NASA Marshall Space Flight Center, ES-84, Huntsville, AL 35812, USA
DATE:: December 1997
JOURNAL:: To appear in:
SUBMITTED::
ACCEPTED::
OTHER_ACCESS::
COPYRIGHT:: Copyright 1997 The Association of Universities for Research in Astronomy, Inc. All Rights Reserved.
LANGUAGE:: English
ABSTRACT::
We examine what we regard as key observational results on GRB 970228
and GRB 970508 and show that the accumulated evidence strongly
suggests that 
-ray bursts (GRBs) are cosmological fireballs.
We further show that the observations suggest that GRBs are not
associated with the nuclear activity of active galactic nuclei, and
that late-type galaxies are more prolific producers of GRBs.
We suggest that GRBs can be used to trace the cosmic history of the
star-formation rate. Finally, we show that the GRB locations with
respect to the star-forming regions in their host galaxies and the
total burst energies can be used to distinguish between different
theoretical models for GRBs.
END:: epreps.stsci//prep1205