Quasars, Feedback, and Galaxy Formation - Tapir
Quasars, Feedback, and Galaxy Formation - Tapir
Quasars, Feedback, and Galaxy Formation - Tapir
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<strong>Quasars</strong>, <strong>Feedback</strong>, <strong>and</strong> <strong>Galaxy</strong><br />
<strong>Formation</strong><br />
Philip Hopkins<br />
01/28/09<br />
Lars Hernquist, T. J. Cox, Eliot Quataert, Gordon Richards,<br />
Volker Springel, Dusan Keres, Brant Robertson, Kevin Bundy,<br />
Paul Martini, Adam Lidz, Tiziana Di Matteo, Yuexing Li, Josh Younger, Sukanya<br />
Chakrabarti, Alison Coil, Adam Myers, <strong>and</strong> many more<br />
Tuesday, December 25, 12
Motivation<br />
WHAT DO AGN MATTER TO THE REST OF COSMOLOGY?<br />
Ø<br />
Every massive galaxy hosts a supermassive black hole<br />
Ø<br />
These BHs accreted most of their mass in bright, short lived quasar<br />
accretion episodes: the “fossil” quasars<br />
Tuesday, December 25, 12
Motivation<br />
WHAT DO AGN MATTER TO THE REST OF COSMOLOGY?<br />
Ø<br />
Black holes are somehow sensitive to their host galaxies:<br />
BH Mass<br />
(~ pc!)<br />
Stellar Velocities (~ kpc)<br />
Ferrarese & Merritt ’00,<br />
Gebhardt+ ’00<br />
Tremaine et al. ‘02<br />
Tuesday, December 25, 12
Scatter in the mass<br />
that “gets down<br />
to” MBH<br />
Scatter in M BH<br />
BHs must<br />
somehow<br />
self-regulate<br />
PFH, Murray, & Thompson 2009<br />
Tuesday, December 25, 12
Simplest Idea:<br />
FEEDBACK ENERGY BALANCE (SILK & REES ‘98)<br />
Ø<br />
Luminous accretion disk near the Eddington limit radiates an energy:<br />
Ø L = er (dMBH/dt) c 2 (er ~ 0.1)<br />
Ø<br />
Total energy radiated:<br />
Ø ~ 0.1 MBH c 2 ~ 10 61 ergs in a typical ~10 8 Msun system<br />
Ø<br />
Compare this to the gravitational binding energy of the galaxy:<br />
Ø<br />
~ Mgal s 2 ~ (10 11 Msun) (200 km/s) 2 ~ 10 59 erg!<br />
Ø<br />
If only a few percent of the luminous energy coupled, it would unbind the<br />
baryons in the galaxy!<br />
Ø<br />
Turn this around: if some fraction h ~ 1-5% of the luminosity can<br />
couple, then accretion must stop (the gas will all be blown out the<br />
galaxy) when<br />
Ø<br />
MBH ~ (a/her) Mgal (s/c) 2 ~ 0.002 Mgal<br />
Tuesday, December 25, 12
Simplest Idea:<br />
FEEDBACK ENERGY BALANCE (SILK & REES ‘98)<br />
Proga et al.<br />
Ø<br />
Needs to come in *bright* stage (where most<br />
BH growth takes place)<br />
z<br />
Ø ~5% of Energy or ~ L/c Momentum<br />
l<br />
l<br />
l<br />
Compton/Ionization heating (Sazonov et al.)<br />
Dusty, momentum driven winds (Murray et al.)<br />
Line-driven winds (Proga et al.)<br />
Ø<br />
See this in observed systems:<br />
l<br />
l<br />
l<br />
BAL winds (Gabel,Arav,et al.)<br />
Warm absorbers? (Krongold,McKernan)<br />
High-z, radio-loud QSOs (Reul<strong>and</strong>,Nesvadba)<br />
z<br />
l<br />
~L/c at ~kpc scales (Tremonti, Hennawi):<br />
l<br />
Tuesday, December 25, 12<br />
Can this impact the galaxy?<br />
R
Motivation<br />
WHAT DO AGN MATTER TO THE REST OF COSMOLOGY?<br />
Ø BH “Downsizing”: Ø Traces SFR Evolution:<br />
BH accretion rate (x1000)<br />
BH mass of<br />
an L* QSO<br />
SFR (points)<br />
Merloni et al. 2007<br />
PFH, Richards, & Hernquist 2007<br />
Tuesday, December 25, 12
Motivation<br />
WHAT DO AGN MATTER TO THE REST OF COSMOLOGY?<br />
Ø<br />
<strong>Quasars</strong> were active/BHs formed when SF shut down...<br />
BH <strong>Formation</strong> Times:<br />
Spheroid <strong>Formation</strong><br />
Times:<br />
Nelan+05; Thomas<br />
+05; Gallazzi+06<br />
PFH, Lidz, Coil, Myers, et al. 2007<br />
Tuesday, December 25, 12
Motivation<br />
MAYBE THIS CAN EXPLAIN OTHER, LONG-STANDING PROBLEMS?<br />
Croton+ 06<br />
Yang+ 03<br />
Why are there no<br />
massive, bulge-dominated<br />
star forming (blue)<br />
galaxies?<br />
Why do massive galaxies<br />
stop growing while their<br />
host halos keep growing?<br />
Tuesday, December 25, 12
Ø<br />
Ø<br />
Ø<br />
Motivation<br />
WHAT DO AGN MATTER TO THE REST OF COSMOLOGY?<br />
Ø<br />
BH <strong>and</strong> <strong>Galaxy</strong> <strong>Formation</strong> is a coupled problem:<br />
Ø<br />
Ø<br />
BH-BH merger rates? Kicks?<br />
Ø<br />
Ø<br />
Need to know galaxy-galaxy mergers<br />
Spin alignment from accretion disks<br />
BH Spins? Jet Physics?<br />
Ø<br />
Triggering mechanisms/feedback/momentum of accreted material<br />
Ø<br />
Ø<br />
Ø<br />
Seed BHs?<br />
Ø<br />
Where do galaxies “take over”? Low-M occupation fraction?<br />
Clusters for cosmology?<br />
Ø<br />
<strong>Feedback</strong> effects on X-ray gas, halo occupation, Mgal-Mhalo<br />
IGM temperature distributions? Metal?, Lya?<br />
Ø<br />
Ø<br />
AGN “preheating” & entropy injection<br />
Comparable metal/mass ejection to stars<br />
Tuesday, December 25, 12
Three Outst<strong>and</strong>ing (Inseparable?) Questions:<br />
Restricts<br />
Triggering<br />
Lightcurves<br />
Initiates/Limits<br />
Determines<br />
Suppresses<br />
Self-<br />
Regulates<br />
Structures<br />
<strong>Feedback</strong><br />
Tuesday, December 25, 12
“Feeding the Monster”<br />
WHY ARE WE INTERESTED IN MERGERS?<br />
PFH et al. 2005<br />
Mergers a long-time c<strong>and</strong>idate<br />
for BH fueling:<br />
• Fast, violent:<br />
Soltan (1982): growth in short-lived QSOs<br />
→ gas dynamics; rapid (~ few 10 7 years)<br />
Angular momentum problem:<br />
perturbed at all radii<br />
• Blend of gas & stellar dynamics:<br />
Lynden-Bell (1967): orbits redistributed<br />
by large, rapid potential fluctuations<br />
→ stellar dynamics; freefall timescale<br />
Tuesday, December 25, 12
“Feeding the Monster”<br />
WHY ARE WE INTERESTED IN MERGERS?<br />
Kravtsov et al.<br />
Ø<br />
Structure grows hierarchically:<br />
must underst<strong>and</strong> mergers<br />
Tuesday, December 25, 12
“Feeding the Monster”<br />
WHY ARE WE INTERESTED IN MERGERS?<br />
Ø<br />
Toomre & Toomre (1972) : the “merger hypothesis”<br />
Ø Spheroids are made by merger of spirals<br />
Tuesday, December 25, 12
“Feeding the Monster”<br />
WHY ARE WE INTERESTED IN MERGERS?<br />
Ø<br />
If BHs trace spheroids, then<br />
*most* growth from mergers<br />
Komossa et al.<br />
Tuesday, December 25, 12
Star <strong>Formation</strong><br />
BH Growth<br />
Tuesday, December 25, 12
“Transition”<br />
vs.<br />
“Maintenance”<br />
Ø<br />
Move mass from Blue to Red<br />
Ø<br />
Keep it Red<br />
Ø<br />
Rapid<br />
Ø<br />
Long-lived (~Hubble time)<br />
Ø<br />
Small scales<br />
Ø<br />
Large (~halo) scales<br />
Ø<br />
“Quasar” mode (high mdot)<br />
Ø<br />
“Radio” mode (low mdot)<br />
Ø<br />
Morphological Transformation<br />
Ø<br />
Subtle morphological change<br />
Ø<br />
Gas-rich/Dissipational Mergers<br />
Ø<br />
Hot Halos & Dry Mergers<br />
Ø<br />
Regulates Black Hole Mass<br />
Ø<br />
Regulates <strong>Galaxy</strong> Mass<br />
Tuesday, December 25, 12
Simplest Experiment:<br />
Ø Rsch ~ few AU ~<br />
10 -6 x our resolution<br />
Ø<br />
BUT, we can get to the BH<br />
radius of influence,<br />
<strong>and</strong> RBondi ~ 10 pc (typical)<br />
l<br />
Accrete from nearby gas<br />
l<br />
~0.1 radiative efficiency<br />
l<br />
~5% couples to local gas<br />
Ø<br />
Let’s see if it works!<br />
Tuesday, December 25, 12
Tuesday, December 25, 12
M-sigma Relation Suggests Self-Regulated BH Growth<br />
PREVENTS RUNAWAY BLACK HOLE GROWTH<br />
Black hole growth:<br />
without feedback<br />
Di Matteo et al. 2005<br />
with feedback<br />
Springel et al. 2004<br />
Tuesday, December 25, 12
Observations & Simulations Suggest this Simple Picture Works<br />
MAKES UNIQUE PREDICTIONS:<br />
Ø<br />
Ø<br />
What is the “fundamental” correlation? Not MBH-s, but MBH-Ebinding (PFH et al.)<br />
Different correlation for “classical” <strong>and</strong> “pseudobulges”<br />
Ø<br />
Both tentatively observed (PFH et al.; Aller; Greene et al.; Hu)<br />
PFH et al. 2007,2008<br />
merger<br />
remnants<br />
secular/<br />
stochastically-fueled<br />
galaxies<br />
Younger, PFH et al. 2008<br />
Tuesday, December 25, 12
Of Course, Not Every AGN Needs a Merger<br />
MORE QUIESCENT GROWTH MODES?<br />
• z~2 QSO: 10 11 Msun in
“Dead” Bulges<br />
(stellar wind/hot<br />
gas halo accretion)<br />
“Seyferts”<br />
(disk-dominated,<br />
secular/minor<br />
mergers)<br />
“Fading” Mergers<br />
(post-starburst<br />
spheroids)<br />
Log(Number Density)<br />
Seyferts<br />
<strong>Quasars</strong><br />
“Blowout”<br />
(Bright<br />
Mergers)<br />
Log(L/L sun<br />
)<br />
Ø<br />
Observed luminosity function: populations at different evolutionary stages<br />
Tuesday, December 25, 12<br />
PFH & Hernquist 2006, 2008
Testing the models:<br />
REMNANT MORPHOLOGY:<br />
~Seyfert-Quasar threshold<br />
at Eddington<br />
• Most mass in “classical” bulges, not “pseudobulges<br />
– But, *are* important below
Columns Evolve<br />
Evolution<br />
Viewing Angle<br />
Bolometric<br />
“Blowout”<br />
phase<br />
B-B<strong>and</strong><br />
Tuesday, December 25, 12
Quasar Lightcurves <strong>and</strong> Lifetimes<br />
Ø<br />
<strong>Feedback</strong> determines the decay of the quasar light curve:<br />
No feedback (“plateau”)<br />
With feedback<br />
(power-law fall)<br />
Ø<br />
Ø<br />
Explosive blowout drives<br />
power-law decay in L<br />
No <strong>Feedback</strong>:<br />
l<br />
l<br />
Runaway growth<br />
(exponential light curve)<br />
“Plateau” as run out of gas<br />
but can’t expel it (extended<br />
step function)<br />
PFH et al. 2006a<br />
Tuesday, December 25, 12
This is Very General:<br />
(EVEN THOUGH NOT ALL AGN ARE MERGER-DRIVEN)<br />
Ø<br />
Almost any (ex. radio) AGN<br />
feedback will share key properties:<br />
l<br />
l<br />
Point-like<br />
Short input (~ tSalpeter)<br />
l<br />
E~Ebinding<br />
Ø<br />
Simple, analytic solutions:<br />
l<br />
l<br />
L ~ (t / tQ) -1.7(ish)<br />
Agrees well with simulations!<br />
Ø<br />
Generalize to “Seyferts”<br />
l<br />
l<br />
Disk-dominated galaxies with<br />
bars<br />
Minor mergers<br />
PFH et al. 2006b,c<br />
Tuesday, December 25, 12
So What Is the “Quasar Lifetime”?<br />
AGN clearly spends<br />
less time here...<br />
... than here<br />
Ø<br />
“Quasar Lifetime”: a conditional, luminosity-dependent distribution<br />
Tuesday, December 25, 12
Directly Apparent in the Observed Eddington Ratio Distribution<br />
Observed<br />
Predicted<br />
L (t/t Q )<br />
(1.5 2.0)<br />
PFH et al. 2009<br />
Tuesday, December 25, 12
Directly Apparent in the Observed Eddington Ratio Distribution<br />
Ø<br />
May be multiple “events,” but<br />
AGN decay/regulation is<br />
self-similar!<br />
Ø<br />
BH, not galaxy,<br />
determines<br />
lightcurve evolution<br />
Tuesday, December 25, 12
Directly Apparent in the Observed Eddington Ratio Distribution<br />
Ruled out by<br />
transverse<br />
proximity effect<br />
t episodic ~ t total<br />
Ø<br />
Complimentary constraints from clustering (Meyers, Croom, Porciani, da Angela)<br />
Ø<br />
BHs grew in
Log(Time at L)<br />
Given the Conditional Quasar Lifetime, De-Convolve the QLF<br />
QUANTIFIED IN THIS MANNER, UNIQUELY DETERMINES THE RATE OF “TRIGGERING”<br />
Same object class & evolutionary<br />
stage, but L ~ Mass<br />
Simple quasar<br />
lifetimes<br />
+ =<br />
Log(L/L sun<br />
)<br />
<strong>Formation</strong> rate/<br />
triggering rate<br />
Observed<br />
luminosity<br />
function<br />
Log(M/M sun<br />
)<br />
Log(L/L sun<br />
)<br />
Ø<br />
If every quasar is at the same fraction of Eddington, the active BHMF<br />
(<strong>and</strong> host MF) is a trivial rescaling of the observed QLF<br />
Tuesday, December 25, 12
Log(Time at L)<br />
+<br />
+ =<br />
Simulated quasar<br />
<strong>Formation</strong> rate/<br />
triggering rate<br />
lifetimes<br />
Log(L/L sun<br />
)<br />
Observed<br />
luminosity<br />
function<br />
Log(M/M sun<br />
)<br />
Log(L/L sun<br />
)<br />
Ø<br />
Ø<br />
Different shapes<br />
Much stronger turnover in formation/merger rate<br />
Ø Large “faint” population of decaying systems: optically dim? (PFH, Hickox, Quataert ‘09)<br />
Tuesday, December 25, 12
+<br />
“Fading”<br />
Mergers<br />
Disks<br />
(young<br />
&<br />
ellipticals)<br />
“Dead”<br />
Ellipticals<br />
Peak<br />
Mergers<br />
Observed<br />
luminosity<br />
function<br />
Ø<br />
Log(L/L sun<br />
)<br />
Return to this picture:<br />
QLF reflects populations at different evolutionary stages<br />
Tuesday, December 25, 12
Testing the models:<br />
NECESSARY CHECKS:<br />
• Predict QLF; clustering; obscuration; scaling laws<br />
PFH08<br />
Di Matteo et al. 08<br />
• There are “enough” mergers: hierarchical growth can account for todays BHs<br />
Tuesday, December 25, 12
Where Does the Energy/Momentum Go?<br />
QUASAR-DRIVEN OUTFLOWS?<br />
(outflow reaches speeds of up to ~1800 km/sec)<br />
T = 0.4 Gyr/h T = 0.5 Gyr/h T = 0.6 Gyr/h<br />
30 kpc / h<br />
T = 0.7 Gyr/h T = 0.9 Gyr/h T = 1.3 Gyr/h<br />
Tuesday, December 25, 12
Outflows are Explosive <strong>and</strong> Clumpy<br />
Ø<br />
Rapid BH growth => point-like<br />
injection<br />
l “Explosion-like”, independent of<br />
coupling<br />
Ø<br />
Clumpy<br />
l ULIRG cold/warm transition (S.<br />
Chakrabarti)<br />
l CO outflows (D. Narayanan)<br />
Ø<br />
Cold shell (through galaxy)<br />
Tuesday, December 25, 12
Quasar Outflows May Be Significant for the ICM & IGM<br />
SHUT DOWN COOLING FOR ~ COUPLE GYR. PRE-HEATING?<br />
Gas Density<br />
Gas Temperature<br />
Tuesday, December 25, 12
Quasar Outflows May Be Significant for the ICM & IGM<br />
SHUT DOWN COOLING FOR ~ COUPLE GYR. PRE-HEATING?<br />
with AGN<br />
feedback<br />
without AGN feedback<br />
simulated vs. observed<br />
profiles<br />
Tuesday, December 25, 12
<strong>Feedback</strong>-Driven Winds<br />
METAL ENRICHMENT & BUILDING THE X-RAY HALO<br />
X-Ray Emission<br />
Cox et al. 2005<br />
Tuesday, December 25, 12
Expulsion of Gas Turns off Star <strong>Formation</strong><br />
ENSURES ELLIPTICALS ARE SUFFICIENTLY “RED & DEAD”?<br />
Springel et al. 2005<br />
No AGN<br />
<strong>Feedback</strong><br />
With AGN<br />
<strong>Feedback</strong><br />
Tuesday, December 25, 12
Expulsion of Gas Turns off Star <strong>Formation</strong><br />
ENSURES ELLIPTICALS ARE SUFFICIENTLY “RED & DEAD”?<br />
PFH, Keres et al. 2008<br />
... but ...<br />
1<br />
No AGN <strong>Feedback</strong><br />
With AGN <strong>Feedback</strong><br />
SFR / SFRPeak<br />
0.1<br />
0.01<br />
0.001<br />
0 1 2 3 0 1 2 3<br />
t - t Peak [Gyr]<br />
... MOST of the gas is still exhausted by star formation/stellar feedback<br />
Tuesday, December 25, 12
AGN or Starburst-Driven Winds?<br />
WHICH ARE MORE IMPORTANT?<br />
PFH, Cox et al. 2007<br />
BHs<br />
Dominate<br />
<strong>Feedback</strong><br />
Stars<br />
Dominate<br />
<strong>Feedback</strong><br />
Halo Mass [M sun ]<br />
Tuesday, December 25, 12
AGN or Starburst-Driven Winds?<br />
WHICH ARE MORE IMPORTANT?<br />
PFH, Cox et al. 2007<br />
Efficient star<br />
formation<br />
Inefficient star<br />
formation<br />
BHs<br />
Dominate<br />
<strong>Feedback</strong><br />
Stars<br />
Dominate<br />
<strong>Feedback</strong><br />
Halo Mass [M sun ]<br />
Tuesday, December 25, 12
Tuesday, December 25, 12
Tuesday, December 25, 12
Maintenance Mode<br />
IS IT ALSO “RADIO”-MODE?<br />
Ø<br />
How important is the “radio” or “maintance” mode?<br />
Scannapieco & Oh ’04:<br />
All “Quasar Mode” <strong>Feedback</strong><br />
Croton et al. ’06:<br />
All “Radio Mode” <strong>Feedback</strong><br />
No FB<br />
With<br />
FB<br />
No FB<br />
With FB<br />
Tuesday, December 25, 12
Maintenance Mode<br />
IS IT ALSO “RADIO”-MODE?<br />
Ø<br />
Know that (non-cooling flow) clusters do look “pre-heated”...<br />
but we also see radio jets doing work:<br />
Ø<br />
What is “typical”?<br />
Fabian (Perseus Cluster)<br />
Allen (X-ray Ellipticals)<br />
Tuesday, December 25, 12
Maintenance Mode<br />
IS IT ALSO “RADIO”-MODE?<br />
Ø<br />
Know that (non-cooling flow) clusters do look “pre-heated”...<br />
but we also see radio jets doing work:<br />
Ho: P(radio) versus Eddington ratio:<br />
Allen: P(jet) versus P(accretion):<br />
Ø<br />
Observational constraints on the power involved are leading the way<br />
Tuesday, December 25, 12
Maintenance Mode<br />
IS IT ALSO “RADIO”-MODE?<br />
Ø<br />
Breakthroughs being made on the<br />
simulation side as well:<br />
Cosmological approximations:<br />
Idealized jets (even MHD ones!):<br />
Sijacki et al.<br />
Tuesday, December 25, 12
Maintenance Mode<br />
IS IT ALSO “RADIO”-MODE?<br />
Ø<br />
Lest we forget, real clusters are messy...<br />
Ø<br />
Gravitational heating, distributed AGN heating, may be important as well<br />
Tuesday, December 25, 12
Summary<br />
Ø<br />
MBH traces spheroid Ebinding<br />
l Suggests self-regulated BH growth<br />
• Which mechanisms dominate BH feedback? When/where?<br />
Ø<br />
If self-regulated, this feedback is potentially radically important:<br />
l Heating gas, ejecting metals, shutting down SF<br />
l Self-regulated decay of QSO luminosity:<br />
• Why are quasar lifetimes generically self-similar?<br />
l Where/what is the transition/maintenance mode role?<br />
• Function of Eddington ratio?<br />
Ø<br />
Most BH growth should come in mergers... but<br />
“are AGN mergers?” is the wrong question: we should ask:<br />
l<br />
“Where (as a function of L, z, d) do mergers vs. secular<br />
processes dominate the AGN population?”<br />
l<br />
l<br />
l<br />
Clustering vs. scale<br />
Host galaxy colors/SFH<br />
Host morphology/kinematics<br />
Tuesday, December 25, 12
Shameless Plug:<br />
Lots of galaxy-side physics that I didn’t get to talk about:<br />
come find me if you want to hear more!<br />
Ø<br />
How Do Disks Survive Mergers?<br />
l (PFH et al. 2008;<br />
PFH, Somerville et al. 2009 [today])<br />
Ø<br />
How Do You Make A (Real) Elliptical?<br />
l (PFH, Rothberg et al. 2008;<br />
PFH, Kormendy, Lauer et al. 2008a-c;<br />
PFH, Cox, & Hernquist et al. 2008)<br />
Ø<br />
How Do You Make A Compact, High-Redshift Elliptical?<br />
(And How Do You Make It Into A Normal Elliptical Today?)<br />
l (PFH, Keres, Cox, Wuyts et al. 2008;<br />
PFH, Quataert et al. 2009;<br />
PFH, Bundy et al. 2009)<br />
Thanks!<br />
Tuesday, December 25, 12