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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

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