Prospects for Infrared AGN Surveys

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Prospects for Infrared AGN Surveys

• Scott Croom (AAO)

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Outline

• What are the key scientific questions?
• The current state of the art regarding AGN
  surveys (mostly 2QZ).
• IR selection of AGN.
• Prospects for FMOS.

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Fundamental questions

• QSO (SMBH) formation evolution
• How?
• When?
• Cosmology
• O, ?, H0 - DONE?
• W(z), dark energy, equation of state
• Evolution of the IGM and the formation of
  galaxies.

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AGN Physics

• Basic questions
• How do AGN form?
• What drives their evolution?
• Unification - the obscured population?
• Issues
• Gal mass vs. BH mass vs. BH Luminosity
• Fuelling variable efficiency, time-scales...
• Triggering mergers, starbursts
• Our view orientation, dust, BLR, NLR...

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Cosmology

• Cosmological parameters
• WMAP, 2dFGRS, SN Ia Done?
• New parameters - w(z), the equation of state etc.
• Galaxy formation the IGM
• Chemical history of the Universe
• When was the gas used up?
• When were most of the metals produced?

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The state of the art

• Large homogeneous optically selected samples
  2dF, SDSS
• Smaller deep X-ray surveys Chandra, XMM

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The 2dF QSO Redshift Survey
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Data release
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• Data fully public
• Available via
• www.2dfquasar.org
• 2QZ CD-ROM
• Includes
• Catalogue
• Spectra
• Completeness masks software

Croom et al. 2003, in press
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QSO Optical LF
Croom et al. 2003
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X-ray LF

• Inconsistent with PLE.
• LDDE is a better fit.
• How do we get consistency with optical?

From Ueda et al. 2003
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Clustering evolution
?
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2QZ vs. 2dFGRS
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The QSO power spectrum

• Fitting possible to 500 h-1Mpc.
• ?0.13?0.02

?CDM
Outram et al. 2003
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The QSO power spectrum

• ?b/?m0.18?0.1
• ?mh0.19?0.05
• 2QZ best fit
• x 2dFGRS best fit
• Marginal detection of baryon wiggles (non-zero
  ?b).

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Spectral properties
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2QZ Key results

• Over 23000 QSO redshifts measured.
• Geometric test ? ?m0.29, ??0.71
• P(k) on scales up to 500 h-1Mpc
• ?b/?m0.18?0.1
• ?mh0.19?0.05
• Clustering evolution ? lifetimes 106-107 years
• Optical LF consistent with PLE (still!)
• Host galaxies LgalLQSO0.4
• No evolution in velocity width for a given L.
• And
• a lasting resource for the community.

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SDSS high z QSOs

• The SDSS will provide
• 100000 QSOs
• Including 7 (currently) at zgt5.7
• High quality photometry and spectra

Fan et al. 2003
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SDSS/2dF Faint QSOs

• 10000 faint QSOs, g22 mag (LRGs!)
• Science (testing QSO formation models)
• breaking the L-z degeneracy in clustering.
• The faint end of the QSO LF.
• QSO environments at z0.7.
• BH mass function via QSO line widths.
• plus improved measurements of LSS, z-space
  distortions etc.

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2MASS red AGN

• 2MASS has used J-K colours to select QSOs (e.g.
  Cutri et al)
• At low redshift there is a significant population
  of red AGN
• 2MASS not deep enough to reach high z
• K15.5 flux limit.
• Much of the red colour will come from the host
  galaxy at low z.

Barkhouse Hall 2001
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IR selection of QSOs

• Near IR colours
• E.g. from red J-K colour
• Drop out techniques
• Mid-IR from Spitzer surveys (e.g. SWIRE see
  Sebs talk).

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K-excess

• QSOs are bluer than stars at UV/optical
  wavelengths.
• But they are also REDDER that stars at near IR
  wavelengths.
• This suggests a K-excess (or KX) selection
  analogous to UVX in the UV/optical (Warren et al.
  2000)

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K-excess
Warren et al. 2000
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KX the NDWFS

• Preliminary results from a KX survey with the
  NOAO Deep Wide-field Survey.
• Deep BRIJHK imaging data.
• Spectroscopy from HYDRA WYFFOS.

Reddening
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The time domain

• Largely unexplored regime.
• Potential science areas
• BH masses via reverberation mapping to high
  redshift (how long will it take?).
• Constraints on winds outflow models via
  variations in intrinsic absorption lines.
• Stratification of the broad line region via
  reverberation mapping of multiple lines.
• Simultaneous observations in optical/IR?

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FMOS surveys

• Based on UKIDSS (DXS) Others.
• Combine with optical spectroscopic of
  brighter/bluer sources. E.g. AAOmega.
• Also relatively low AGN surface density means
  that AGN surveys could be merged with other
  surveys (c.f. 2dFGRS/2QZ)
• extra science too.

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FMOS advantages

• Efficient for red/reddened objects
• The un-obscured population.
• Probes the same spectral window as optical at low
  z
• Spectral analysis -gt BH mass estimates, AGN
  physics -gt cause of evolution?
• Large FOV on an 8m
• 1 hr (J22 mag) -gt 50 QSOs per FMOS field.
• LSS/cosmology, QSO environments triggering.

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Summary

• The near-IR is an ideal place to select and
  observe QSOs.
• Only ultra deep surveys (X-rays?) would use 400
  fibres in FMOS.
• Large area QSO surveys should be a component of
  an integrated survey.
• The time domain is still largely unexplored