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Answers (and questions) from quasar surveys

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),

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Answers (and questions) from quasar surveys

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  1. 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

  2. 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…

  3. Why quasar surveys (then)? • 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.

  4. Why quasar surveys (now)? • Highest impact 2QZ work: • QSO luminosity function. • Clustering evolution: implications for SMBHs and galaxy formation. • Spectral analysis.

  5. The 2QZ: Vital statistics 2dF QSO Redshift Survey • UKST photometry • UV/optical colour selection: u,bJ,r • bJ=18.0-20.85 • 722 deg2 • 2dF spectroscopy • z~0.3-3.0 • Vol: ~19 Gpc3 • 23660 QSOs Croom et al. (2001, 2004)

  6. 2SLAQ: Vital Statistics 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)

  7. The 2SLAQ QSO LF Croom et al. 2008; (SDSS LF: Richards et al. 2006)

  8. The 2SLAQ+SDSS QSO LF Croom et al. (2008), see also Richards et al. (2005)

  9. Downsizing… • Brightest QSOs peak at z~2.5 (or higher). • Faintest QSOs peak at z~1 (or lower). Croom et al. (2008)

  10. Downsizing… (X-ray) Hasinger et al. (2005)

  11. 2QZ clustering evolution Croom et al. (2005) see also Myers et al. (2006; 2007), Porciani et al. (2004; 2006)

  12. QSO bias Croom et al. (2005)

  13. QSO DMH host mass Croom et al. (2005)

  14. The blue cloud and red sequence • MDH(QSO)~ few x 1012h-1Msun ~ transition mass? Combo-17: Borch et al. (2006) Simulations: Croton et al. (2006) SDSS: Blanton et al. (2006)

  15. 2SLAQ QSO clustering da Angela et al. (2008)

  16. 2SLAQ QSO clustering da Angela et al. (2008) Lidz et al. (2006), z=2

  17. 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. • rBLR~L0.5 Kaspi et al. (2005)

  18. 2SLAQ, 2QZ and SDSS line widths Fine et al. (2008)

  19. Line width dispersion Fine et al. (2008)

  20. Comparison with Models Fine et al. (2008) – comparison to Hopkins, Hernquist et al. merger models.

  21. 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)

  22. Unanswered questions • Radio emission – how? • The build up of SMBHs at z>3. • Feedback, does it work? If so, how?

  23. Feedback… • After 1st passage. • Merger of BHs. • Quasar phase. • Quasar has ended. (T = time in Gyr) Hopkins et al. (2005)

  24. Evidence for mergers ACS: Bennert et al. (2008) Low-z HST host galaxy imaging (Schade et al. 2000)

  25. 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?

  26. Hexabundles • 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 1x61 Bland-Hawthorn et al. (2008)

  27. 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)

  28. 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 z=0.5-2.5. • 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.

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