Constraining the Nature and
Impact of AGN
Evan Scannapieco
School of Earth and Space Exploration
Arizona State University
Downsizing & Preheating
Cavaliere, Menci, &Tozzi (1999)
Ueda etal 2004
Simulating Quasars
Thacker, ES & Couchman 2006, ApJ, 653, 86
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OpenMP version of the ‘Hydra’ SPH code (Pearce &
Couchman 1997, Thacker et al 2003, Thacker & Couchman, 2006)
2x 6403 mass elements (half gas, half dark matter)
 Largest cosmological SPH simulation ever carried out at
that time
 147 h-1 Mpc box, mass resolution
2.2x108 baryons, 1.2x109 DM
140,000 cpu hours, down to
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z=1.2
Total
disk output ~ 5 TB
(1/5th size of Millennium Run)
Locally adaptive Fourier-mesh scheme
Simulating Quasars
Thacker, ES & Couchman 2006, ApJ, 653, 86
Quasar are associated with 3:1 mergers,
“LIGHTBULB”-- L-Edd as in Wyithe & Loeb
BH mass calculated from baryonic velocity dispersion
5% of energy in light is put into outflow
Modification of work done on
SN outflows
(ES, Thacker, & Davis 2001,
Thacker, ES, & Davis 2002)
Outflows are modeled as
thin spherical shells.
Host galaxy remains intact.
Quasar tracking
1 2 3 4 5 6
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Merger model requires that we
find groups and identify
mergers while the simulation
is running
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Need fast group finder
Previous work used group
finder to identify the mass of
objects and determine star
formation events
Simple to adapt this to include
a group index
9
7 8
10
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12
Time
QuickTime™ and a
Video decompressor
are needed to see this picture.
Galaxy Clusters
1046
LX
44
10
42
10
1040
This
Works!
3.2
LXT
Temperature/ keV
Thacker, ES,
& Couchman
(2006)
Quasar Luminosity Function
Thacker, ES,
& Couchman (2006)
Correlation function of Quasars
Blue=sim
2dF results (Croom et al 2001)
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Our simulation
agrees with the
observed turn-up
in the small scale
clustering of
quasars
CF is explained by
the “halo model”
of clustering
No need for
“special physics”
Sloan binary quasar data
(Hennawi et al 2005)
Quasar-Galaxy cross correlation function
Blue=gg
Red=qg
Hash=DEEP2
(from Coil etal 06)
blue line = 2x1012
DM halos
Could this be
3-body interactions?
Thacker, ES, & Couchman (2006)
Dynamical Friction
Dynamical Friction
Three-body interactions
|V12|
| V12  ^r12 |
V12 • ^
r12
Sunyaev Zel’dovich Effect
Comparison Simulation
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2x 3203 mass elements (half gas, half dark matter)
67.5 h-1 Mpc box, mass resolution
2.2x108 baryons, 1.2x109 DM
Mergers are exactly as the
were in the feedback run, but no
outflows are included.
Outputs every 50 Myrs!
QuickTime™ and a
MPEG-4 Video decompressor
are needed to see this picture.
Cross-Correlations
6 arcmin
6 arcmin
Cross-Correlations - Ellipticals
Measuring AGN Feedback
Measuring AGN Feedback
Thanks!

Clustering:
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Enhanced clustering at small separations appears
to be a robust feature of mergers.
This appears to be driven by statistics and not
dynamics. Needs to be quantified better…
SZ Observations:
 Provide a direct way of measuring AGN feedback
 Coadding Bulges - Radio Loud = ETot(MBulge)
South Pole Telescope
Sensitivity: 10 K
Beam: 1 arcmin
Status: Initial
Engineering Obs.
Atacama Cosmology
Telescope
Sensitivity: 2 K
Beam: 2 arcmin
Status: Initial
Engineering Obs.
Cross-Correlations - QSOs