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AGNs among ROSAT Blank Field Sources

I. Cagnoni·M. Elvis·D. -W. Kim·J. -S. Huang·A. Celotti·F. Nicastro
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Abstract

We selected a sample of sources with high X-ray over optical flux ratio from the ROSAT PSPC archives. Out of the 16 sources in our sample, one is a (possibly extreme) BL Lac and two are AGNs. Six more sources are tentatively classified as AGNs on the basis of their X-ray properties and of our optical-IR imaging. For one of the AGNs and for the AGN-like blanks we find a discrepancy between the lack of absorption indicated by the X-ray spectra and the presence of red counterparts in their error circles. We discuss various possibilities to reconcile the X-ray and optical information.

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I. Cagnoni, M. Elvis, D. -W. Kim, J. -S. Huang, A. Celotti, F. Nicastro. 2002-12-10. AGNs among ROSAT Blank Field Sources. https://arxiv.org/abs/astro-ph/0212231

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