XMM-Newton observations of ultraluminous X-ray sources in nearby galaxies

被引：55

作者：

Foschini, L

Di Cocco, G

Ho, LC

Bassani, L

Cappi, M

Dadina, M

Gianotti, F

Malaguti, G

Panessa, F

Piconcelli, E

Stephen, JB

Trifoglio, M

机构：

[1] CNR, Ist Astrofis Spaziale & Fis Cosm, Sez Bologna, I-40129 Bologna, Italy

[2] Carnegie Inst Washington Observ, Pasadena, CA 91101 USA

来源：

ASTRONOMY & ASTROPHYSICS | 2002年 / 392卷 / 03期

关键词：

galaxies : active; galaxies : general; X-rays : binaries; X-rays : galaxies;

D O I：

10.1051/0004-6361:20020950

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

An XMM-Newton study of ultraluminous X-ray sources (ULX) has been performed in a sample of 10 nearby Seyfert galaxies. Eighteen ULX have been found with positional uncertainty of about 4". The large collecting area of XMM-Newton makes the statistics sufficient to perform spectral fitting with simple models in 8 cases. The main results of the present minisurvey strengthen the theory that the ULX could be accreting black holes in hard or soft state. In some cases, the contribution of the ULX to the overall X-ray flux appears to be dominant with respect to that of the active nucleus. In addition, 6 ULX present probable counterparts at other wavelengths (optical/infrared, radio). A multiwavelength observing strategy is required to better assess the nature of these sources.

引用

页码：817 / 825

页数：9

共 48 条

[1] Super-Eddington fluxes from thin accretion disks? [J].