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The AGN Content of Hard X-ray Surveys

Published online by Cambridge University Press:  12 April 2016

Andrea Comastri ,
Cristian Vignali  and
Marcella Brusa
Andrea Comastri
Affiliation:
Osservatorio Astronomico di Bologna, via Ranzani 1, I40127 Bologna, Italy
Cristian Vignali
Affiliation:
Dept. of Astronomy and Astrophysics, Penn State University, 525 Davey Lab - University Park, PA 16802, USA
Marcella Brusa
Affiliation:
Dipartimento di Astronomia, Universita’ di Bologna, via Ranzani 1-40127 Bologna, Italy

Abstract

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Multiwavelength observations of the hard X-ray selected sources discovered by BeppoSAX, Chandra and XMM-Newton surveys have significantly improved our knowledge of the AGN population. The increasing number of X-ray obscured AGN so far discovered confirms the prediction of those AGN synthesis models for the X-ray background based on the Unified scheme. However, follow-up optical observations of hard X-ray selected sources indicate that their optical properties are quite varied and the simple relations between optical and X-ray absorption are by no means without exception. Moreover there is evidence of a substantial number of luminous X-ray sources hosted by apparently normal galaxies. In this paper the results obtained from multiwavelength observations of hard X-ray selected sources discovered by BeppoSAX and XMM-Newton are presented and briefly discussed.

Type
Part 3. X-ray Surveys for AGN
Information
International Astronomical Union Colloquium , Volume 184: AGN Surveys , 2002 , pp. 235 - 244
Copyright
Copyright © Astronomical Society of the Pacific 2002

References

Akiyama, M. et al. 2000, ApJ, 532, 700 CrossRefGoogle Scholar
Akiyama, M., Ohta, K., Ueda, Y. 2001, ApJ, in press (astro-ph/0111037)Google Scholar
Baldi, A., Molendi, S, Comastri, A., Fiore, F., Matt, G., Vignali, C. 2001, ApJ, in press (astro-ph/0108514)Google Scholar
Barger, A. et al. 2001, AJ, 122, 2177 CrossRefGoogle Scholar
Brandt, W.N. et al. 2001, AJ, in press (astro-ph/0108404)Google Scholar
Comastri, A., Setti, G., Zamorani, G., Hasinger, G. 1995, A&A, 296, 1 Google Scholar
Comastri, A. 2000, in Proc. Conf. “X-ray Astronomy ‘999: Stellar Endpoints, AGN, and the Diffuse Background (astro-ph/0003437)Google Scholar
Comastri, A. et al. 2001, MNRAS, 327, 781 CrossRefGoogle Scholar
Comastri, A. et al. 2002, ApJL, submitted (see also astro-ph/0109117)Google Scholar
Della Ceca, R. et al. 1999, ApJ, 524, 674 CrossRefGoogle Scholar
Fabbiano, G., Kim, D.W., Trinchieri, G., 1992, ApJS, 80 531 CrossRefGoogle Scholar
Fabian, A.C., Iwasawa, K. 1999, MNRAS, 303 L34 CrossRefGoogle Scholar
Fiore, F. et al. 1999, MNRAS, 306 L55 CrossRefGoogle Scholar
Fiore, F. et al. 2000, New Astronomy, 5, 143 CrossRefGoogle Scholar
Fiore, F. et al. 2001a, MNRAS, 327, 771 CrossRefGoogle Scholar
Fiore, F. et al. 2001b, Proc. of the ESO/ECF/STSCI Workshop on “Deep Fields”, Garching October 2000 (astro-ph/0102041)Google Scholar
Giacconi, R. et al. 2001, ApJ, 551, 624 CrossRefGoogle Scholar
Gilli, R., Salvati, M., Hasinger, G. 2001, A&A, 366 407 Google Scholar
Gioia, I.M. et al. 1990, ApJS, 72, 567 CrossRefGoogle Scholar
Hasinger, G. et al. 1998, A&A, 329, 482 Google Scholar
Hasinger, G., Altieri, B., Arnaud, M. et al. 2001, A&A, 365, L45 Google Scholar
La Franca, F. et al. 2002, ApJ, submittedGoogle Scholar
Lehmann, I. et al. 2000, A&A, 354, 35 Google Scholar
Lehmann, I. et al. 2001a, A&A, 371, 833 Google Scholar
Lehmann, L, Hasinger, G., Murray, S.S., Schmidt, M. 2001b, Proc. of theSymposium “X-rays at Sharp Focus”, in press (astro-ph/01 09172)Google Scholar
Madau, P., Ghisellini, G., Fabian, A.C. 1994, MNRAS, 270, L17 CrossRefGoogle Scholar
Maiolino, R. et al. 2000, A&A, 355, L47 Google Scholar
Maiolino, R. et al. 2001, A&A, 365, 2 Google Scholar
Norman, C, 2001, ApJ, submitted (astro-ph/0103198)Google Scholar
Rosati, P. et al. 2001, ApJ, in press (astro-ph/0110452)Google Scholar
Setti, G., Woltjer, L., 1989, A&A, 224, L21 Google Scholar
Tozzi, P. et al. 2001, ApJ, in press (astro-ph/0103014)Google Scholar
Ueda, Y. et al. 1999, ApJ, 518, 656 CrossRefGoogle Scholar
Vignali, C, Mignoli, M., Comastri, A., Maiolino, R., Fiore, F. 2000, MNRAS, 314, L11 CrossRefGoogle Scholar
Vignali, C, Comastri, A., Fiore, F., La Franca, F. 2001, A&A, 370, 900 Google Scholar