The Sources of the CDF-N --- Classification Schemes, Absorption Estimates and Broadband SEDs

1
The Sources of the CDF-N --- Classification
Schemes, Absorption Estimates and Broadband SEDs

• Stephan Frank
• Patrick Osmer, Smita Mathur

Extragalactic Surveys A Chandra Science
Workshop November 2006
2
(No Transcript)
3
Interesting Open Questions

• Fraction of obscured to unobscured sources
• Ballantyne et al. (2006) R (1z)0.3
• Gilli et al. (2006) R redshift independent
• Luminosity dependence
• Where is the obscuration happening?
• Mismatch between optically and X-ray derived NH
  (Maiolino et al. 2004)
• NIR/optical/UV not at same place as X-ray
• aOX - LUV relation (Strateva et al. 2005
  Steffen et al. 2006)
• Breaks down for X-ray faint sources
• Absorption as main contributor
• Faint AGN X-ray underluminous ?

4
Estimating X-ray and Optical absorption
NH (X-ray) (from hardness ratio
NH (NIR-optical-UV) (from SED fit)
5
NH (X) NH (optical) correlated ?
X-ray absorbed, Optically red QSOs
X-ray unabsorbed, Optically red QSOs
Unabsorbed, luminous QSOs
X-ray abs., opt. normal QSOs
6
Redshift effects for the NH estimate
7
Fraction of X-ray absorbed QSOs
8
Fraction of X-ray absorbed QSOs
Cf. Gilli et al. (astro-ph/0610939)
9
Lx-LUV breaks down for faint AGN
10
aOX Luv breaks down for faint AGN
11
Summary

• No correlation between X-ray and NIR-optical-UV
  absorption
• Fraction of X-ray absorbed QSOs
• Redshift independent
• Luminosity dependent
• aox LUV relation breaks down for X-ray faint
  QSOs
• X-ray absorption main culprit
• Possibly X-ray underluminous sources ?
• Detailed spectral analyses to disentangle host
  contributions necessary ? multiwavelength picture
• Frank, Osmer, Mathur (2006, in preparation)

12
(No Transcript)