We present an X-ray surface-brightness distribution and a temperature map of the Ophiuchus cluster of galaxies observed by ASCA. The Ophiuchus cluster is a nearby rich cluster located at z = 0.028 having an angular extent of ∼1°. The observations were made by five pointings that cover the whole cluster. After deconvolution with the ASCA complex response function, we obtained the surface-brightness distribution with an angular resolution of 2′ and a temperature map with 8′ resolution. The X-ray surface-brightness distribution shows a nearly spherically symmetric distribution, except for a 15σ image excess at the position of 10′ to the north of the cluster center. On the other hand, a hot region with a temperature > 13keV is spread over a region of 20′ × 30′ at 20′ to the west of the cluster center. Because these characteristics are similar to those of the Coma cluster, we conclude this cluster has never relaxed dynamically, and is also recently experienced a merger.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science