Start Presentation: Host Galaxies as Obscurers

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Author: Johannes Buchner

Homepage: http://astrost.at/istics/

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Host Galaxies as Obscurers

Abstract: AGN surveys in the X-ray regime have revealed that the majority of AGN (3/4) are obscured, with 1/3 showing Compton-thick column densities. This indicates that hidden accretion is an important phase in the growth of super-massive black holes. However, it remains unclear how much of this obscuration is already provided by the host galaxy itself; a question which cannot be answered using a central point source alone. Our novel approach employs 600 long gamma-ray bursts to “x-ray” the metal gas in galaxies at. This requires a good understanding of the obscurer and biases introduced. The highly complete SHOALS survey allowed us to discover a relation between stellar masses and X-ray derived column densities NH, pointing to the host galaxy as the dominant obscurer of LGRBs. This obscuration is expected according to local galaxy analogues and current hydrodynamic cosmological simulations. We could then constrain the typical covering factor of the nuclear AGN obscurer (torus) alone by subtracting away the host galaxy contribution, under some caveats related to star-formation rate of AGN hosts. Our findings recast the discussion of the evolution and luminosity-dependence of the AGN obscured fraction.

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Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent Mergers
Disturbed/merger fractions similar LGRB-AGN

Obscuration by merger at high-L should become more prevalent