The BeppoSAX High Energy Large Area Survey - IV. On the soft X-ray properties of the hard X-ray-selected HELLAS sources

被引：16

作者：

Vignali, C

Comastri, A

Fiore, F

La Franca, F

机构：

[1] Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy

[2] Osservatorio Astron Bologna, I-40127 Bologna, Italy

[3] Osservatorio Astron Roma, I-00044 Frascati, Italy

[4] VeppoSAX Sci Data Ctr, I-00131 Rome, Italy

[5] Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy

来源：

ASTRONOMY & ASTROPHYSICS | 2001年 / 370卷 / 03期

关键词：

surveys; galaxies : active; galaxies : nuclei; galaxies : starburst Xrays : galaxies;

D O I：

10.1051/0004-6361:20010286

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present a comprehensive study of the soft X-ray properties of the BeppoSA X High-Energy Large Area Survey (HELLAS) sources. A large fraction (about 2/3) of the hard X ray selected sources is detected by ROSAT. The soft X-ray colors for many of these objects, along with the 0.5-2 keV flux upper limits for those undetected in the ROSAT band, do imply the presence of absorption. The comparison with the ROSAT Deep Survey sources indicates that a larger fraction of absorbed objects among the HELLAS sources is present, in agreement with their hard X-ray selection and the predictions of the X-ray background synthesis: models. Another striking result is the presence, of a soft (additional) X-ray component in a significant fraction of absorbed objects.

引用

页码：900 / 908

页数：9

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