SUMMARY OF PROPOSAL 61040

DR. TADAYASU DOTANI
DOTANI@astro.isas.jaxa.jp

ISAS
KANAGAWA JAPAN 229
SAGAMIHARA
3-1-1 YOSHINO-DAI
Tel: 0427-51-3911 Fax: 0427-59-4258
Medium: 4GBDAT
Subject: X-RAY BINARIES

ORIGIN OF THE ENIGMATIC BEHAVIORS OF CIR X-1


ABSTRACT

We propose observations of the violent and enigmatic X-ray binary system Cir X-1 over the whole orbital period. Cir X-1 contains a neutron star with weak magnetic field, like other low-mass X-ray binaries, whereas it exhibits large vriety of enigmatic behaviour, whose origin is not known yet. We hope to obtain important information on the super-Eddignton accretion, jet formation, partial covering absorption, line/edge formation, spectral state variability, and Z/atoll source unification scheme through comprehensive asca observations. Compariosn with the previous short ASCA observation at phase zero is also useful to identify the origin of the long-term variation observed by the RXTE.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
KAZUMI ASAIISASJAPAN
YOUICHI ARUGAISASJAPAN

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)CIR X-1
2
230.1708-57.1667 70 ksY
Y
P
500.00000
7

TARGET 1

OBSERVATION EPOCHS ARE: OBS1=0.05+-0.03, OBS2=0.15+-0.03, OBS3=0.3+-0.05, OBS4=0.5+-0.05, OBS5=0.7+-0.05, OBS6=0.85+-0.03, OBS7=0.95+-0.03. ALL THE OBSERVATIONS SHOULD FIT WITHIN ONE ORBIT.
Epoch: 50083.3925 Period: 16.52590000 Min: 0.0000Max: 1.0000