SUMMARY OF PROPOSAL 72033
CALIFORNIA INSTITUTE OF TECHNOLOGY
MS 200-47
PASADENA
CA USA 91125
Tel: (626) 395-3038 Fax: (626) 449-8676
Medium: CD ROM
Subject: X-RAY BINARIES
STUDY OF TYPE I X-RAY BURSTING, TRANSIENT NEUTRON STARS IN QUIESCENCE
ABSTRACT
Recent re-analysis of archival ASCA observations of three transiently accreting neutron stars (Cen X-4, Aql X-1, and 4U 1608--52) suggests that some of the quiescent emission is powered by the heated core. Accretion may still contribute to the quiescent luminosity. Variability provides a discriminant between these two sources of thermal surface emission. We propose to re-observe these objects while they are in quiescence. This, combined with the archival ASCA data, will allow us to search for variability, on timescales of weeks to years, in the quiescent luminosities and spectra. The proposed observations will also provide benchmarks for future observations with, e.g., AXAF and XMM.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| L. BILDSTEN | UCB | USA |
| E. BROWN | UCB | USA |
| G. PAVLOV | PSU | USA |
| V. ZAVLIN | MPE | GERMANY |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)CEN X-4 | C | 224.5913 | -31.6687 | 35 ks | Y | Y | P | 0.04400 | 2 |
TARGET 1
SEPARATE OBSERVATIONS BY 30-200 DAYS, PREFERRING SHORTER SEPARATION. OBJECT SHOULD BE NOT DETECTED (<4 C/S) BY RXTE/ASM FOR MORE THAN 2 CONSECUTIVE DAYS FOR 30 DAYS PRIOR TO FIRST OBSEVATION.
MONITORED OBSERVATION:
Min. Interval: 2590.000ksecMax. Interval: 17280.000 ksec