Nature of X-ray Sources in the Outskirts of Clusters of Galaxies
The X-ray Universe 2008, Granada, Spain, 27 - 30 May 2008, pp.1-4, (Full Text)
- Publication Type: Conference Paper / Full Text
- City: Granada
- Country: Spain
- Page Numbers: pp.1-4
- Akdeniz University Affiliated: Yes
Abstract
Three nearby (z<0.08) clusters of galaxies (A194, A1060, A2255) have been analyzed for the X-ray point source
properties with XMM-Newton data. More than 100 sources are detected from cluster fields by a multi-band
detection technique. The source properties are studied by individual spectral fitting and constructing a cumulative
log(N)&log(S) for a flux limit of Fx > 1 × 10−14ergcm−2
s
−1
. The results are compared with the properties of
field galaxies from Lockman-Hole. About 3 σ excess of X-ray sources was found from the cluster regions. The
optical follow-up sources from A2255 field are further observed by TUG 1.5 m telescope of RTT-150. Considering
the luminosity range of the sources in our study (LX > 1040 erg/s) the X-ray emission from accretion processes
are taken into account rather than thermal processes of hot halo. Since cluster regions are highly populated with
galaxies which are surrounded by high density ICM, clusters are the places with very high probability of galaxy
collisions and close encounters. These physical conditions may disturb the equilibrium of individual galaxies with
the surrounding gas of fuel and may trigger accretion onto LMXBs, fuel AGNs and awake black-holes. Regarding
also the distribution of sources within the clusters, we notice that the brighter sources are likely to reside in the
cluster outskirts. Based on our study results, infall induced AGN activities and quenching of point-like emissions
by high dense cluster core are discussed