Transcript Cosmic evolution of SMBHs

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
Outline
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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…
Why quasar surveys (then)?
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Original 2QZ science aims (circa 1995):
• LSS on scales 1 to 1000h-1Mpc.
• Clustering evolution for Ωm and bias.
• Alcock-Pacynski (1979) test for ΩΛ.
• QSO Luminosity function.
• In the mean time:
• SNe and Dark Energy.
• M-σ relation.
• Reverbration mapping and “virial methods”.
• WMAP and other CMB measurements.
Why quasar surveys (now)?
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Highest impact 2QZ work:
• QSO luminosity function.
• Clustering evolution: implications for
SMBHs and galaxy formation.
• Spectral analysis.
The 2QZ: Vital statistics
2dF QSO Redshift Survey
• UKST photometry
• UV/optical colour
selection: u,bJ,r
• bJ=18.0-20.85
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722 deg2
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2dF spectroscopy
• z~0.3-3.0
• Vol: ~19 Gpc3
• 23660 QSOs
Croom et al. (2001, 2004)
2SLAQ: Vital Statistics
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2dF-SDSS LRG And QSO
Survey
SDSS photometry
ugriz (~UVX) selection
g<21.85
192 deg2
2dF spectroscopy
z~0.3-3.0
Vol: ~5 Gpc3
10,000 faint QSOs
+ 10,000 LRGs (see David
Wake talk)
Richards et al. (2005), Croom et al. (2008)
The 2SLAQ QSO LF
Croom et al. 2008; (SDSS LF: Richards et al. 2006)
The 2SLAQ+SDSS QSO LF
Croom et al. (2008), see also Richards et al. (2005)
Downsizing…
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Brightest QSOs peak
at z~2.5 (or higher).
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Faintest QSOs peak
at z~1 (or lower).
Croom et al. (2008)
Downsizing… (X-ray)
Hasinger et al. (2005)
2QZ clustering evolution
Croom et al. (2005)
see also Myers et al. (2006; 2007), Porciani et al. (2004; 2006)
QSO bias
Croom et al. (2005)
QSO DMH host mass
Croom et al. (2005)
The blue cloud and red sequence
SDSS: Blanton et al. (2006)
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Combo-17:
Borch et al. (2006)
Simulations:
Croton et al. (2006)
MDH(QSO) ~ few x 1012h-1Msun ~ transition mass?
2SLAQ QSO clustering
da Angela et al. (2008)
2SLAQ QSO clustering
Lidz et al. (2006), z=2
da Angela et al. (2008)
BH masses and the virial method
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Broad-line emission
region is assumed to
be virialised and so
the width of a line
gives vBLR.
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The radius-luminosity
relation derived from
reverberation mapping
campaigns gives rBLR.
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rBLR~L0.5
Kaspi et al. (2005)
2SLAQ, 2QZ and SDSS line widths
Fine et al. (2008)
Line width dispersion
Fine et al. (2008)
Comparison with Models
Fine et al. (2008) – comparison to Hopkins, Hernquist et al. merger models.
MBH vs MDH
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Mean zero-point:
log(MBH)=8.40.2 at
log(MDH)=12.5
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Well matched to
Robertson et al.
(2006) simulations.
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Bigger points =
higher redshift.
Fine et al. (2006)
Unanswered questions
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Radio emission – how?
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The build up of SMBHs at z>3.
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Feedback, does it work? If so, how?
Feedback…
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After 1st passage.
Merger of BHs.
Quasar phase.
Quasar has
ended.
(T = time in Gyr)
Hopkins et al. (2005)
Evidence for mergers
ACS: Bennert et al. (2008)
Low-z HST host galaxy imaging (Schade et al. 2000)
Dissecting galaxies
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Single fibres:
• Missed flux.
• No spatial
information.
• Systematic biases.
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Can we combine the
multiplexing of single
fibre surveys and the
power of integral-field
spectroscopy?
Hexabundles
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Fibres that can use existing positioning
technology, but with multiple cores.
Cladding only needs to be ~5-10λ thickness.
1x91 manufactured, 1x397 by 2010.
Expect excellent photometric qualities.
1x19 selective illumination
Bland-Hawthorn et al. (2008)
1x61
Strawman concept
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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.
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Bland-Hawthorn et al. (2008)
Summary
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2SLAQ QSO LF:
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Not pure luminosity evolution.
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Significant downsizing: faint AGN peak at lower z.
QSO Clustering:
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QSOs inhabit similar dark matter halos at z=0.5-2.5.
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No luminosity dependence found so far.
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Implies a range of accretion efficiencies for SMBHs.
BH mass distribution:
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Distribution of BL widths narrows at bright magitudes.
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Appears bounded by Mass fn and L/LEdd.
BH mass vs DMH mass:
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M-M relation not evolving.