SUMMARY OF PROPOSAL 52043
PRESIDENT AND FELLOWS OF HARVARD COLLEGE
440 HOLLYOKE CENTER, 1350 MASS AVE.
CAMBRIDGE
MA USA 02138
Tel: (617)495-5501 Fax: (617)495-2900
Medium: 2GB8MM
Subject: X-RAY BINARIES
WHY DO SOME X-RAY BURSTERS HAVE HARD X-RAY TAILS ?
ABSTRACT
We propose to investigate the X-ray spectral properties of four bursters detected above 30 keV with SIGMA: GX354-0, SLX1732-304, KS1731-260 and A1742-294. All four sources have been poorly studied in the 1-10 keV band. We propose to obtain ASCA observations to constrain the origin of the hard X-ray emission, as required in particular for on-going theoretical investigations. Taking advantage of the high spectral resolution and extended energy coverage of ASCA, we will study the coupling between the cool blackbody-like radiation emitted at the neutron star surface and the Comptonizing corona (i.e. Compton cooling). This is required to understand the residual differences observed between black hole and neutron star systems, with respect to hard X-ray emission.
CO-INVESTIGATORS
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)GX354-0 | 2 | 262.9875 | -33.8344 | 10 ks | N | N | P | 31.40000 | 1 |
| 2)KS1731-260 | 2 | 263.5542 | -26.0833 | 10 ks | N | N | P | 30.00000 | 1 |