ASCA observation of the compact group of galaxies SCGG 223

作者：Jin, GX^*; Xu, HG; Chen, L; Liu, DB; Ling, JJ

来源：Chinese Astronomy and Astrophysics, 2001, 25(1): 48-52.

DOI：10.1016/S0275-1062(01)00042-X

• X-rays
• galaxies compact groups of galaxies

Optical observations of the compact group of galaxies SCGG 223 show that the velocity dispersion in it is as high as 1106 km S-1, While the group itself seems to be relaxed. Numerical simulations also suggest that SCGG 223 is virialized. Therefore, it is inferred that the gravitational mass in SCGG 223 may be comparable with that in a typical galaxy cluster, and the intra-group gas may be extremely hot. In order to explore these! unusual implications, we observed SCGG 223 in X-rays with the ASCA satellite in February, 1999. The gas temperature and the 0.5 similar to 10 keV luminosity are found to be kT = 1.4(-0.4)( 0.6) keV and 9.85(-2.04)( 6.11) x 10(43)J S-1, respectively, which show that SCGG 223 belongs to usual galaxy groups. Due to the lack of enough photon counts, we are not able to perform the X-ray spectroscopic imaging to deduce the radial distribution of the gravitating mass in SCGG 223, by the use of which crucial comparison would have been made with the optical virial mass. Thus, for a complete understanding of SCGG 223, further X-ray observations with satellites such as XMM is desirable.

• 出版日期2001-3
• 单位上海交通大学