SUMMARY OF PROPOSAL 51272

DR. KATSUJI KOYAMA
KOYAMA@CR.SCPHYS.KYOTO-U.AC.JP

KYOTO UNIVERSITY
KYOTO JAPAN 606-01
KYOTO
KITASHIRAKAWA-OIWAKE-CHO SAKYO-KU
Tel: 075-753-3833 Fax: 075-701-5377
Medium: 2.5GB8MM
Subject: COSMIC X-RAY BACKGROUND AND DEEP SURVEYS AND OTHER

WHAT IS VARIABLE AT THE GALACTIC CENTER?


ABSTRACT

Observational results suggesting the existence of a massive black hole at the Galactic center has been accumulating (e.g. Genzel et al. 1996). ASCA also suggested the presence of the past AGN activity, from the hot plasma and 6.4 keV line at the molecular cloud (Koyama et al. 1996). Time variability of the center, if any would be more direct evidence of the black hole. However, previous results of the time variability now became controversial, because Maeda et al (1996) discovered variable binary source (eclipsing buster) in the vicinity of the galactic center. ASCA can only detect the galactic center X-rays at present. Thus we propose to monitor the Galactic center after September 1994.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
YOSHITOMO MAEDAKYOTO UNIVERSITYJAPAN
YASUO TANAKAMPEGERMANY
TOSHIAKI TAKESHIMAGSFCUSA
SHIGEO YAMAUCHIIWATE UNIVERSITYJAPAN
MASAAKI SAKANOKYOTO UNIVERSITYJAPAN
MAMIKO NISHIUCHIKYOTO UNIVERSITYJAPAN

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)SGRA*
1
266.4167-29.0078 80 ksN
Y
P
1.00000
1

TARGET 1

WE HOPE THAT OUR OBSERVATION WILL BE PERFORMED DURING THE SPRING 1997 OBSEVATION WINDOW..