Transcript LSS in the 2dF QSO Survey

Prospects for Infrared AGN
Surveys
Scott Croom (AAO)
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.
Fundamental questions:
• QSO (SMBH) formation & evolution:
– How?
– When?
• Cosmology:
– Ω, Λ, H0 - DONE?
– W(z), “dark energy”, equation of state…
– Evolution of the IGM and the formation of
galaxies.
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...
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?
The “state of the art”
• Large homogeneous optically selected
samples: 2dF, SDSS
• Smaller deep X-ray surveys: Chandra,
XMM
The 2dF QSO Redshift
Survey
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Data release
• 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
X-ray LF
• Inconsistent
with PLE.
• LDDE is a
better fit.
• How do we get
consistency
with optical?
From Ueda et al. 2003
Clustering evolution
?
2QZ vs. 2dFGRS
The QSO power spectrum
•Fitting possible to
~500 h-1Mpc.
•=0.130.02
CDM
Outram et al. 2003
The QSO power spectrum
•b/m=0.180.1
•mh=0.190.05
•+ 2QZ best fit
•x 2dFGRS best fit
•Marginal detection
of baryon wiggles
(non-zero b).
Spectral properties
2QZ Key results
• Over 23000 QSO redshifts measured.
• Geometric test  m=0.29, =0.71
• P(k) on scales up to ~500 h-1Mpc:
•
•
•
•
•
– b/m=0.180.1
– mh=0.190.05
Clustering evolution  lifetimes ~ 106-107 years
Optical LF consistent with PLE (still…!)
Host galaxies: Lgal~LQSO0.4
No evolution in velocity width for a given L.
And…
– a lasting resource for the community.
SDSS & high z QSOs
• The SDSS will provide:
– ~100000 QSOs
– Including 7 (currently) at z>5.7…
– High quality photometry and spectra
Fan et al. 2003
SDSS/2dF Faint QSOs
• ~10000 faint QSOs, g’~22 mag (+LRGs!)
• Science (testing QSO formation models):
– breaking the L-z degeneracy in clustering.
– The faint end of the QSO LF.
– QSO environments at z~0.7.
– BH mass function via QSO line widths.
• plus improved measurements of LSS, zspace distortions etc.
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:
– K~15.5 flux limit.
• Much of the red colour will come from the
host galaxy at low z.
Barkhouse & Hall 2001
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 Seb’s talk).
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)
K-excess
Warren et al. 2000
KX & the NDWFS
• Preliminary results from a KX survey with
the NOAO Deep Wide-field Survey.
• Deep BRIJHK imaging data.
• Spectroscopy from HYDRAReddening
& WYFFOS.
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?
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.
FMOS advantages
• Efficient for red/reddened objects:
– The un-obscured population.
• Probes the same spectral window as
optical at low z:
– Spectral analysis -> BH mass estimates, AGN
physics -> cause of evolution?
• Large FOV on an 8m:
– 1 hr (J~22 mag) -> ~50 QSOs per FMOS field.
– LSS/cosmology, QSO environments &
triggering.
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…