SUMMARY OF PROPOSAL 71193
ISAS
3-1-1 YOSHINODAI
SAGAMIHARA
KANAGAWA JAPAN 229-8510
Tel: 0427-59-8150 Fax: 0427-59-8455
Medium: 4GBDAT
Subject: COSMIC X-RAY BACKGROUND DEEP SURVEYS AND OTHER
ASCA OBSERVATION OF FAINT HARD X-RAY SOURCES
ABSTRACT
The origin of the Cosmic X-ray background (CXB) has been one of the key issues of X-ray astronomy. We propose follow up observations of 8 selected hard X-ray sources discovered by the serendipitous source survey project with ASCA. AXAF observations of these sources to determine positions were already approved. These sources have 2-10 keV fluxes below 5 x 10**(-13) erg/cm2/s. ASCA 0.7-2/2-10 keV counting rates that require them to either have power law photon indecies flatter than 1.0, or if they have intrinsic slopes of 1.7, have column density greater than Nh = 2 x 10**22/cm2.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| TADAYUKI TAKAHASHI | ISAS | JAPAN |
| YOSHIHIRO UEDA | ISAS | JAPAN |
| YOSHITAKA ISHISAKI | TOKYO METRO U. | JAPAN |
| KOUJI OHTA | KYOTO U. | JAPAN |
| MASAYUKI AKIYAMA | KYOTO U. | JAPAN |
| TORU YAMADA | TOHOKU U. | JAPAN |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)AXJ1025+4714 | A | 156.4921 | 47.2397 | 50 ks | N | Y | P | 0.00500 | 1 |
| 2)AXJ0431-0526 | A | 67.9287 | -5.4405 | 70 ks | N | Y | P | 0.00300 | 1 |
| 3)AXJ1510+0742 | A | 227.5975 | 7.7006 | 70 ks | N | Y | P | 0.00300 | 1 |
| 4)AXJ1951+5609 | A | 297.7650 | 56.1658 | 90 ks | N | Y | P | 0.00200 | 1 |