Where are the type 2 AGNs?

M. Salvati; R. Maiolino

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arXiv · astro-ph/0001332

Where are the type 2 AGNs?

M. Salvati·R. Maiolino

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Abstract

Most of the energy of the X-ray background is contributed by sources with a hard X-ray spectrum, harder than the spectrum observed in nearby type 1 AGNs. The hard background contributors are conventionally identified with type 2 AGNs, obscured by circumnuclear matter both in the optical and in the soft X rays. However, preliminary results of identification programs seem to find systematically few type 2 AGNs in samples selected with obscuration insensitive criteria. We discuss this issue, and assess the various scenarios which are being proposed to solve the discrepancy.

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M. Salvati, R. Maiolino. 2000-01-19. Where are the type 2 AGNs?. https://arxiv.org/abs/astro-ph/0001332

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