Answers and questions from quasar surveys

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Answers (and questions) from quasar surveys
Scott Croom (IoA, University of Sydney)
With contributions from Stephen Fine (Sydney),
Jose da Angela, Tom Shanks (Durham)Gordon
Richards (Drexel), Lance Miller, Ana Babic
(Oxford), Joss Bland-Hawthorn, Simon Ellis
(Sydney) the 2QZ, 2SLAQ and AUS teams
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Outline

• Why quasar surveys (reasons, then and now)?
• 2QZ and 2SLAQ.
• Evolution the quasar luminosity function.
• Clustering, bias and host mass.
• BH masses from quasar spectra.
• Unanswered questions

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Why quasar surveys (then)?

• Original 2QZ science aims (circa 1995)
• LSS on scales 1 to 1000h-1Mpc.
• Clustering evolution for Om and bias.
• Alcock-Pacynski (1979) test for O?.
• QSO Luminosity function.
• In the mean time
• SNe and Dark Energy.
• M-s relation.
• Reverbration mapping and virial methods.
• WMAP and other CMB measurements.

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Why quasar surveys (now)?

• Highest impact 2QZ work
• QSO luminosity function.
• Clustering evolution implications for SMBHs and
  galaxy formation.
• Spectral analysis.

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The 2QZ Vital statistics

• 2dF QSO Redshift Survey
• UKST photometry
• UV/optical colour selection u,bJ,r
• bJ18.0-20.85
• 722 deg2
• 2dF spectroscopy
• z0.3-3.0
• Vol 19 Gpc3
• 23660 QSOs

Croom et al. (2001, 2004)
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2SLAQ Vital Statistics

• 2dF-SDSS LRG And QSO Survey
• SDSS photometry
• ugriz (UVX) selection
• glt21.85
• 192 deg2
• 2dF spectroscopy
• z0.3-3.0
• Vol 5 Gpc3
• 10,000 faint QSOs
• 10,000 LRGs (see David Wake talk)

Richards et al. (2005), Croom et al. (2008)
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The 2SLAQ QSO LF
Croom et al. 2008 (SDSS LF Richards et al. 2006)
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The 2SLAQSDSS QSO LF
Croom et al. (2008), see also Richards et al.
(2005)
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Downsizing

• Brightest QSOs peak at z2.5 (or higher).
• Faintest QSOs peak at z1 (or lower).

Croom et al. (2008)
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Downsizing (X-ray)
Hasinger et al. (2005)
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2QZ clustering evolution
Croom et al. (2005)
see also
Myers et al. (2006 2007), Porciani et al. (2004
2006)
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QSO bias
Croom et al. (2005)
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QSO DMH host mass
Croom et al. (2005)
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The blue cloud and red sequence
Combo-17 Borch et al. (2006)
Simulations Croton et al. (2006)
SDSS Blanton et al. (2006)

• MDH(QSO) few x 1012h-1Msun transition mass?

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2SLAQ QSO clustering

• da Angela et al. (2008)

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2SLAQ QSO clustering
Lidz et al. (2006), z2

• da Angela et al. (2008)

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BH masses and the virial method

• Broad-line emission region is assumed to be
  virialised and so the width of a line gives vBLR.
• The radius-luminosity relation derived from
  reverberation mapping campaigns gives rBLR.
• rBLRL0.5

Kaspi et al. (2005)
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2SLAQ, 2QZ and SDSS line widths
Fine et al. (2008)
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Line width dispersion
Fine et al. (2008)
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Comparison with Models
Fine et al. (2008) comparison to Hopkins,
Hernquist et al. merger models.
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MBH vs MDH

• Mean zero-point log(MBH)8.4?0.2 at
  log(MDH)12.5
• Well matched to Robertson et al. (2006)
  simulations.
• Bigger points higher redshift.

Fine et al. (2006)
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Unanswered questions

• Radio emission how?
• The build up of SMBHs at zgt3.
• Feedback, does it work? If so, how?

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Feedback

• After 1st passage.
• Merger of BHs.
• Quasar phase.
• Quasar has ended.
• (T time in Gyr)

Hopkins et al. (2005)
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Evidence for mergers
ACS Bennert et al. (2008)
Low-z HST host galaxy imaging (Schade et al. 2000)
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Dissecting galaxies

• Single fibres
• Missed flux.
• No spatial information.
• Systematic biases.
• Can we combine the multiplexing of single fibre
  surveys and the power of integral-field
  spectroscopy?

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Hexabundles

• Fibres that can use existing positioning
  technology, but with multiple cores.
• Cladding only needs to be 5-10? thickness.
• 1x91 manufactured, 1x397 by 2010.
• Expect excellent photometric qualities.

1x19 selective illumination
1x61
Bland-Hawthorn et al. (2008)
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Strawman concept

• FLAMES on VLT 24 arcmin f-o-v
• Existing robot positioner (AAO built OzPoz).
• 40 1x397 hexabundles (7 arcsec diameter).
• Feeding 4 MUSE (Laurent et al. 2006) style
  spectrographs.
• Science
• Galaxy dynamics, merging.
• Stellar populations.
• AGN hosts.

Bland-Hawthorn et al. (2008)
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Summary

• 2SLAQ QSO LF
• Not pure luminosity evolution.
• Significant downsizing faint AGN peak at lower
  z.
• QSO Clustering
• QSOs inhabit similar dark matter halos at
  z0.5-2.5.
• No luminosity dependence found so far.
• Implies a range of accretion efficiencies for
  SMBHs.
• BH mass distribution
• Distribution of BL widths narrows at bright
  magitudes.
• Appears bounded by Mass fn and L/LEdd.
• BH mass vs DMH mass
• M-M relation not evolving.