SUMMARY OF PROPOSAL 61195

DR. NOBUYUKI KAWAI
NKAWAI@POSTMAN.RIKEN.GO.JP

RIKEN
SAITAMA JAPAN 351-01
WAKO
2-1 HIROSAWA
Tel: 048-467-9336 Fax: 048-462-4640
Medium: 4GBDAT
Subject: CLUSTERS OF GALAXIES AND SUPERCLUSTERS

IS THE POWERFUL RADIO GALAXY HERCULES A IN A CLUSTER OR NOT?


ABSTRACT

We propose to observe Hercules A with ASCA for 40 ksec. In the soft X-ray image, it has X-ray emission clearly extended on a Mpc scale, but there is no strong evindence in optical band for the presence of cluster of galaxies in its environment. With ASCA, we can determine accurately the properties of the high energy X-ray spectrum of this peculiar object. If Hercules A is indeed dominated by thermal emission, this would strongly argue for a cluster environment and thus would resolve a long-standing debate. Alternatively Her A may be proven to have AGN component in it X-ray emission, if the temperature is too low or if a power-law component is contained.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
WOLFGANG BRINKMANNMPEGERMANY
JOACHIM SIEBERTMPEGERMANY

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)HERCULES A
2
252.7850 4.9795 40 ksN
Y
P
0.21000
1