AGN Outflows in a Cosmological
Context: An Empirical Approach
Robyn Levine
with Nick Gnedin
JILA, University of
Colorado
Fermilab
Cosmological Simulation
dark matter distribution
A Description of Outflows
• AGN distribution
- luminosity function
- density bias
- fraction of AGN with outflows
• Spherical Outflow Model
Luminosity Function
(LB ,z)dLB 
* L*
f
b
(LB L* )  (LB L* )
dLB
Schirber & Bullock 2002
2dF

GOODS
LB B-band luminosity
of AGN (in units L,B)
f
faint-end slope
(constant in z1.58)
b bright-end slope
(z-dependent)
Sample Simulation
Box
density
profile + AGN
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Radio-loud
Quasars
• Collimated jets of
relativistic plasma
• Spreads into
overpressured cocoon
BAL AGNs
• Clouds ejected at v ≤ 1% c
• ~10% covering fraction?
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Radio loud jets
10% of AGN
BAL outflows
50% of low-L AGN
Crenshaw et al. 1999
20% of high-L AGN
Hewett & Foltz 2003
AGN Outflows
•
•
•
•
Spherical symmetry
Similar treatment for BAL outflows and RLQ
tAGN << tHubble
2 expansion phases
– Sedov-Taylor phase (energy conserved)
E k  Lk t age
– Pressure Equilibrium phase

P  (1 m )nB kBTIGM .
Sample Simulation
Box
AGN +
outflows
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Lya forest constraints on F(z)
• Outflows create voids in the Lya forest
• Low-z
– Use baryon fraction for forest, WLya (Penton,
Stocke, & Shull 2004) 99.6% free for voids in
simple model
– WLya combined with NH-1+m relation of Davé et
al. (1999) 70-97% free for voids
• High-z
– Studies of gaps in Lya forest predict voids occupy
< 20% for 1.7 < z < 3.8 (Duncan et al. 1989)
Kinetic Fraction ek = Lk / Lbol
Ly-a forest at z=0
Ly-a forest at z=2-3
AGN Bias
• AGN trace high
density regions:
a
 AGN   m
• AGN more
biased at higher
redshift
larger bias  smaller filling fraction
Weak Lensing Arithmetic
Weak Lensing = Gravity
Gravity = Total Matter (x 8pG/c4)
Total Matter = Dark Matter + Baryons
AGN have enough energy to move all the gas
in the universe over cosmological distances…
Can Outflows affect P(k)?
Two Competing Effects…
AGNs move gas from
small to large scales
P(k)
Clustering of AGNs
increases power
P(k)
That’s A Mess!
• If outflows affect > 10% of the volume:
>1% reduction in large-scale power
• AGN are highly clustered:
transfer of small-scale power to large
scales, fBfAGNbAGN2~ 1%
We do not know even the sign of the effect!
Summary
 Even with small mechanical efficiencies,
AGN outflows fill the IGM by z~2
 AGN outflows potentially affect the matter
power spectrum
redistribute baryons (from small to large
scales)  decreases power
bias in AGN distribution  increases power