The Fraction of Compton-thick AGN

It is $38^{+8}_{-7}\%$

Puerto Varas / Mar 2015

Johannes Buchner

astro-ph:1501.02805

in collaboration with A. Georgakakis, K. Nandra,
M. Brightman, ML. Menzel, L. Hsu, M. Salvato, C. Rangel, J. Aird, A. Merloni

Data

2000 AGN from

  • CDFS 4Ms
  • AEGIS-XD
  • COSMOS
  • XMM-XXL (20 sq deg)

Diff. to previous works

Aird+10 Ueda+14 Buchner+15
sources without counterpart yes yes
photometric redshift uncertainty yes yes yes
+systematic uncertainty yes
absorption model yes yes
soft scattering component (fixed) yes
Compton reflection component yes

Diff. to previous works

Aird+10 Ueda+14 Buchner+15
Handles ambiguous solutions N/A yes
Assumed column density distribution N/A LDDE free
Assumed evolution model LDDE LDDE free

Results

Conclusions: AGN Model

  1. Fraction of obscured AGN: $77^{+4}_{-5}\%$
  2. Fraction of CT AGN: $38^{+8}_{-7}\%$
  3. Luminosity-dependence evolves with z -- mass downsizing?