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THE MODERATELY LARGE SCALE
STRUCTURE OF QUASARS
Jari Kotilainen (Tuorla Observatory)
HIGH Z QUASARS AND GALAXY FORMATION
High z quasars: lighthouses of sites of galaxy formation
quasar space density vs BH growth rate vs SFR history
=> mergers trigger both SF and quasar activity?
=> rapid decline of BH activity at low z
Merloni et al. 2005
BHs in all (?) local massive bulges
Milky Way: M ~3 x 106 Msun
=> all massive galaxies host a remnant BH from a quasar phase?
Kormendy 2004
tight MBH – Mbulge – σbulge
correlations (at low z)
masers
gas
stars
nearby quasar hosts: massive
bulge-dominated galaxies
The most distant quasar (z = 6.4):
molecular gas, dust, SF, metals and BH
Barth et al. 2003
How did massive bulges and SMBHs form in < 1
Gyr?
QUASAR HOSTS AT HIGH REDSHIFT (z > 1)
Kotilainen et al. 2007 ApJ 660, 1039
Falomo et al. 2007 ApJ, in press
VLT + ISAAC non-AO imaging =>
30 hosts at 1 < z < 2
VLT+NACO AO imaging =>
two RLQ hosts (z ~2.5 and z ~2.9)
two RQQ hosts (z ~2.1 and z ~2.5)
Evolution of quasar host luminosity
RLQ hosts ~10 x more
luminous (massive)
BH mass? mass accretion rate?
BH mass threshold for radio activity?
RLQ
c.f. clustering properties, SEDs
passive evolution into local
massive spheroids
no decrease in luminosity ?
=> early epoch for the latest merger
decrease in luminosity ?
=> tight quasar - host co-evolution
different for RLQs and RQQs ?
RQQ
c.f. hierarchical structure formation…
… where BHs are fuelled and
galaxies grow by mergers
=> predict decrease in host
luminosity
=> NOT observed up to z = 2
Di Matteo et al.
2005
more recent models: AGN/SN feedback
Granato et al. 2004, Bower et al. 2006
WORK IN PROGRESS...
evolution of MBH – Mbulge relation with z?
spectra of resolved quasars at 1 < z < 3
images => Mbulge
spectra => virial MBH
z = 1.8
z = 2.5
MORE WORK IN PROGRESS...
CDM => massive density peaks in early
Universe are strongly clustered: cores of
rich clusters => clustering of high z quasars
for radio galaxies: threshold DM
halo (BH) mass required to produce
significant radio emission...
Magliocchetti et al. 2005
...but no radio luminosity dependence of
clustering/DM content/BH mass
Magliocchetti et al. 2005
also: lensing, close companions...
Falomo et al. 2005