SUMMARY OF PROPOSAL 63012
UNIVERSITY OF OXFORD
NUCLEAR PHYICS LABORATORY, KEBLE ROAD
OXFORDSHIRE UK OX1 3RH
Tel: 44-1865 273374 Fax: 44-1865 273390
Medium: CD ROM
Subject: X-RAY BINARIES
GS1826-24: THE FIRST 2HR PERIOD LMXB?
ABSTRACTGS1826-24 was first discovered by Ginga in 1988 and originally suggested to be a soft X-ray transient black-hole candidate. However, bursts have recently been detected in X-rays by SAX and in the optical counterpart by us, thereby confirming a neutron star primary. More importantly, our fast optical photometry reveals a 2hr modulation, plus irregular variability that is reminiscent of X1636-536 and X1735-444. If confirmed as the orbital period, this places GS1826-24 in a unique evolutionary position amongst LMXBs. We propose here to use ASCA to undertake the first detailed X-ray spectral study, in particular (a) to search for soft X-ray spectral features, (b) to undertake a spectral analysis of the bursts, (c) to investigate the structure of the short-term optical variations.
|CO-I NAME ||INSTITUTE ||COUNTRY |
|LEE HOMER||UNIVERSITY OF OXFORD||UK|
| ERIK KUULKERS||UNIVERSITY OF OXFORD||UK|
| DARRAGH O'DONOGHUE||SA ASTR. OBSERVATORY||S AFRICA|
|TARGET NAME||PRI||RA||DEC||TIME||TC||OFF||GIS||SIS CNT||OBS|
|1)GS1826-24|| 1||277.3675||-23.7970|| 20 ks||N||N||P||400.00000||1|
TARGET 1NOTE THAT WE SHALL ENDEAVOUR TO ARRANGE FOR SIMULTNEOUS OPTICAL OBSERVATIONS FROM SAAO ONCE THE ASCA SCHEDULING IS KNOWN.