Overdensity of X-Ray Sources in the Field of Two Nearby Clusters of Galaxies: XMM-Newton View of A 194 and A 1060

Publications of the Astronomical Society of Japan

Haba, Yoshito¹  Hudaverdi, Murat¹  Ercan, E. Nihal³  Furuzawa, Akihiro²  Tawara, Yuzuru²  Kunieda, Hideyo¹  Tanaka, Takeshi¹ 

[1]Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602

[2]EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602

[3]Bogaziçi University, Physics Department, 80815 Bebek, Istanbul, Turkey

关键词: "galaxies: clusters: individual (Abell 194;    Abell 1060)";   

DOI  :  10.1093/pasj/58.6.931

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Twonearbyclustersofgalaxies,A194($$z=0.018$$)andA1060($$z=0.0114$$),havebeenanalyzedfortheirX-raypoint-sourcepropertieswithXMM-NewtonEPIC-PNdata.Amulti-bandsourcedetectiontechniquewasappliedtobothoftheclusters,resultingin46sourcesfromtheA194fieldand32sourcesfromtheA1060field,respectively.Thecumulative$$log(N)hbox{--}log(S)$$forafluxlimitof$$F_{mathrm{X}}geq1imes10^{-14},mathrm{erg},mathrm{cm}^{-2},mathrm{s}^{-1}$$wascalculatedandcomparedwiththatoftheLockmanHole.A$$sim3,sigma$$excessofX-raysourceswasfoundfortheclusterregions.Consideringthehigherfractionobservedinopticalstudiesfromtheclusters,weestimatethattheclustersourcedensityis6-timeshigherthantheblank-fieldsourcedensity,and15-timeshigherthanthelocalgroup.OurX-rayselectedsourceshaveluminosityvaluesof$$10^{39.6}leqL_{mathrm{X}}leq10^{41.4},mathrm{erg},mathrm{s}^{-1}$$,inwhichX-rayemissionfromLMXBs,hothalosandstarburstgalaxiesbecomesnoticeable.Thesignificanceofthesource-densityexcessgraduallyvanishesforsourceswith$$L_{mathrm{X}}geq10^{40.5},mathrm{erg},mathrm{s}^{-1}$$,atwhichpointthesourcedensitybecomescomparabletothatoftheblank-fieldlevel.Consideringthisconfinedlow-luminosityrangeandtheX-raytoopticalluminosityratios($$L_{mathrm{X}}/L_{mathrm{B}}$$),theobservedoverdensityisascribedtoAGNfuelingbyitsinfallintoclusterenvironmentfor$$L_{mathrm{X}}leq10^{40.5},mathrm{erg},mathrm{s}^{-1}$$intheX-rayluminosityfunction.However,thequenchingofAGNactivitybythedeepclusterpotentialexplainswhytheexcessofthesourcedensityvanishesforbrightersources.

【 授权许可】

Unknown