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On the nature of X-ray Bright Optically Normal galaxies

A. Comastri·M. Brusa·P. Ciliegi·M. Mignoli·F. Fiore·R. Maiolino·P. Severgnini·A. Baldi·S. Molendi·C. Vignali·F. La Franca·G. Matt·G. C. Perola
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Abstract

Multiwavelength observations of the hard X-ray selected sources by Chandra and XMM-Newton surveys have significantly improved our knowledge of the objects responsible of the hard X-ray background. A surprising finding is the discovery of a population of optically dull, X-ray bright galaxies emerging at 2-10 keV fluxes of the order of 10^{-14} erg cm^{-2} s^{-1}. We present preliminary results of multiwavelength observations of a few objects serendipitously discovered in the field of XMM-Newton and Chandra observations and intensively studied at longer wavelengths.

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A. Comastri, M. Brusa, P. Ciliegi, M. Mignoli, F. Fiore, R. Maiolino, P. Severgnini, A. Baldi, S. Molendi, C. Vignali, F. La Franca, G. Matt, G. C. Perola. 2002-03-03. On the nature of X-ray Bright Optically Normal galaxies. https://arxiv.org/abs/astro-ph/0203019

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