SUMMARY OF PROPOSAL 51267

JUN KATAOKA
KATAOKA@astro.isas.jaxa.jp

INSTITUTE OF SPACE AND ASTRONAUTICAL SCIENCE
KANAGAWA JAPAN 229
SAGAMIHARA
YOSHINODAI3-1-1
Tel: 0427-51-3911(2612) Fax: 0427-59-4253
Medium: 2.5GB8MM
Subject: COSMIC X-RAY BACKGROUND AND DEEP SURVEYS AND OTHER

CROSS IDENTIFICATION OF THE 'NEW HARD SOURCE' DETECTED IN LSS - ONE OF THE MOST PROBABLE CANDIDATES FOR CXB -


ABSTRACT

In the ASCA Large Sky Survey(LSS),we detected about 70 sources, some of which have extremely hard spectrum. This result indicates a possibility to solve the 'spectral paradox',which has puzzuled astrophysicists for more than 30 years. We propose to observe LSS1983+310 , one of the hardest sources detected in LSS(GIS photon index 0.9). Preliminary optical identification shows that spectrum of the candidate seems to have peculiar line profiles, indicating this could be a 'rare' kind of object. We will also observe it with ROSAT HRI this year. The deep observation of this source with ASCA gives us a new sight to understand the origin of the Cosmic Xray Background.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
YOSHIHIRO UEDAISASJAPAN
TADAYUKI TAKAHASHIISASJAPAN
TAKESHI TSURUKYOTO UNIV.JAPAN
HAJIME INOUEISASJAPAN
MASAAKI SAKANOKYOTO.UNIV.JAPAN
MASAYUKI AKIYAMAKYOTO.UNIV.JAPAN
KOUJI OHTAKYOTO.UNIVJAPAN
TORU YAMADATOUHOKU.UNIVJAPAN
YASUSHI OGASAKANASA/GSFCJAPAN
YOSHITAKA ISHISAKITOKYOMET.UNIVJAPAN

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)LSS1983+310
2
198.3413 31.0097 80 ksN
Y
P
0.00200
2

TARGET 1

50KSEC*2(TOTAL 100KSEC) OBSEVATIONS ARE REQUIRED. TIME INTERVAL IS NOT LIMITED STRICTLY, BUT ABOUT A HALF YEAR IS RECOMMENDED.