Xmm-newton observatıons of lumınous sources ın nearby galaxıes ngc 4395, ngc 4736, and ngc 4258
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Dosyalar
Tarih
2013
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
IOP PUBLISHING LTD
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
We present the results of a study of non-nuclear discrete sources in a sample of three nearby spiral galaxies (NGC 4395, NGC 4736, and NGC 4258) based on XMM-Newton archival data supplemented with Chandra data for spectral and timing analyses. A total of 75 X-ray sources have been detected within the D-25 regions of the target galaxies. The large collecting area of XMM-Newton makes the statistics sufficient to obtain spectral fitting for 16 (about 20%) of these sources. Compiling the extensive archival exposures available, we were able to obtain the detailed spectral shapes of diverse classes of point sources. We have also studied temporal properties of these luminous sources. Eleven of them are found to show short-term (less than 80 ks) variation while eight of them show long-term variation within factors of similar to 2-5 during a time interval of similar to 2-12 years. Timing analysis provides strong evidence that most of these sources are accreting X-ray binary systems. One source that has properties different from others was suspected to be a supernova remnant, and our follow-up optical observation confirmed this. Our results indicate that sources within the three nearby galaxies are showing a variety of source populations, including several ultraluminous X-ray sources, X-ray binaries, transients together with a super soft source, and a background active galactic nucleus candidate.
Açıklama
WOS: 000314944100015
Anahtar Kelimeler
galaxies: individual (NGC 4736, NGC 4395, NGC 4258), X-Rays: Binaries, X-Rays: Galaxies
Kaynak
Astronomical Journal
WoS Q Değeri
Q2
Scopus Q Değeri
Cilt
145
Sayı
3
