# Presentation: 153652

## Quasar Heating in Structure Formation

- Evan Scannapieco
- Kavli Institute for Theoretical Physics
- UC Santa Barbara

## Peng Oh

**Peng Oh**
**UC Santa Barbara**

**Rob Thacker**
**Queen’s University**

**Hugh Couchman**
**McMaster University**

**Marc Davis**
**UC Berkeley**

## What Determines L*?

- Moore etal (1999)

- RDCS1252 (z=1.23), Rosati etal (2004)

**Notes:**
So they way we got into this work is thinking about
What sets L* The characteristic scale of galaxies.

## A Classic Argument

- Rees & Ostriker (1977)

**nkT**
******n****2**

**> t****hubble**

-      

- Problem #1
- Overcooling
- (25%-40% condensed)

- (Suginohara & Ostriker 1998; Lewis et    al 2000; Thacker et al 2000; Davé et al 2001)

- Dekel & Silk (1986)

**For virial density today,**
**Gives few times 10****12**

**Notes:**
Not enough to collect up some matter gravatationally...
Cooling...

## Prob # 2: Antihierarchical Evolution

**Notes:**
A deeper problem
Avishai also showed the evolution of the bugle fraction

## AGN in the X-ray

- Ueda etal 2004

**Notes:**
You could say, well when you’re completely lost you invoke
Feedback to come and fix things.   Actually that’s not true,
When you’re completely lost you change the IMF.
Also is you look at clusters there are strong signs of extra enegy input.

## B-band Quasar Luminosity Function

- Every 3:1 merger lights a quasar.
- Each shines at its Eddington  luminosity for a time proportional to the dynamical time of the galaxy.

- Wyithe & Loeb (2003)... see also Kauffmann & Haehnelt

- Mbh  vc,3005

- Ferrarese (2002)

**Notes:**
Downsizing below redshift 2.
Rate of formation of bulges.

## Clusters: X-ray Emission

** ****L****X**** ~ M ********gas**** T****1/2**
** ****T  ~ M****2/3**** ********DM****1/3**** **
**L****X**** ~** ******gas**** ********DM****-1/2 ****T****2**
- Virialized Gas:
-      Lx ~ 

- Preheated Gas:
- gas ii
-      Lx ~ 

- Mushotzky and Scharf 1997

**Clusters: X-ray Emission**

- 1 keV~ 100 keV cm2

**Kaiser (1991)**

## AGN Heating

**AGN Heating**

- Radio jets

- 3C47, Leahy (1996)

- ~10%

-  BAL Winds

- ~All

- Murray, Chiang, Grossman, & Voit 1995

## ES & Oh (2004) model

- Some small fraction of an AGNs luminosity is converted to mechanical input associated with jets or winds.
- Energy deposited into a thin shell (Sedov-Taylor blast)
- Post-shock entropy of the IGM directly impacts growth of further generations, if it heat things to the point that cooing can not occur within a Hubble time, then you stop forming stars.

## ES & Oh (2004) model

**ES & Oh (2004) model**

## Predictions

**Predictions**

**Dotted lines stradle**
**outflow efficiencies**
**of 2.5% and 10%, **
**central blue line is 5%**
**Big galaxies host large quasars, and can recover from feedback at only at high redshift.**

**Notes:**
Reproduces the same trend seen in galaxies as and does well for clusters... but I don’t wan’t to go into it here,
Beacause I’d rather spend my time telling you about our new results, which are the first large-scale cosmological simulation
To include quasar winds.

## Simulation Modeling

**Simulation Modeling**

- Modification of work done on SN outflows

- Thacker, ES & Couchman 2006, in prep

- (ES, Thacker, & Davis 2001,  Thacker, ES, & Davis 2002)

- Outflows are modeled as thin spherical shells
- Host galaxy remains intact.

- Again quasars are associated with 3:1 mergers,
- But now with a BH mass calculated from gas mass
- 5% of energy in light is put into outflow

**Notes:**
This higher-redshift work has some interesting implications for the discussion yesterday
About preheating... I don’t have time to go into it here, but if you ask me about
It at the end I can show you that.

## Code Details

**Code Details**

- 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 SPH simulation ever carried out at that time
- 147 h-1 Mpc box, mass resolution
- 2.2x108 baryons, 1.2x109 DM

**Locally adaptive Fourier-mesh scheme**

- 140,000 cpu hours, down to
- 	z=1.2
- Run on 256 processor WestGrid, 	Alberta CA
- Total disk output ~ 5 TB 	 (1/5th size of Millennium Run)

**Notes:**
We wanted to capture the behavior over a wide-dynamical range of 
Quasars, galaxies, and clusters... so we carried out a very large simulation

## Galaxy Clusters

**Temperature/ keV**

**L****X**

**10****40**

**10****42**

**10****44**

**10****46**

**L****X********T****3.2**

## Quasar Luminosity Function

**Quasar Luminosity Function**

**Notes:**
Lesson is that semianalytics don’t always capture everything.

## Fundamental differences between the semi-analytic & simulation models

- 1.) In the simulation we don’t eject the gas from the quasar host galaxy itself.  This gas isn’t counted in the semianalytic model.
- 2.) In simulation shock the surrounding material that has substructure.  Effect of shock impacting uniform cloud versus cloud with substructure are very different.  **OVERCOOLING!**
- IF #1 we need to do more than stop accretion
- IF #2 we need either need more feedback, or....

**Notes:**
If it turns out that 2 is the key issue, then we might need (a) more efficient feedback

## Naab, Ostriker et al (2006)

**Naab, Ostriker et al (2006**)

## Quasar-Galaxy cross correlation function

**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?

- Seen in SDSS (Serber etal 2006)

**Notes:**
Upturn very difficult to measure accurately (too
	few quasars) M_B < -22

## Dynamical Friction

**Dynamical Friction**

## Dynamical Friction

**Dynamical Friction**

## Three-body interactions

**Three-body interactions**

**Notes:**
Predicts that the “extra” galaxy should have more
Energy that you would otherwise expect...
May prove to be a way to quantify if quasars-merger connection

## Conclusions

**Semianalytical models:**** show that quasars outflows**
** ****	****are a promising explanation for the ****antihierarchical behavior**** of galaxy and quasars, and the properties of clusters. **
**Simulations: **
**Merger model ****reproduces correlation function**** of quasars very well.**
**Cross-correlation function shows enhancement**** at small separations, probably due to 3 body interactions, may be a diagnostic of merger-nature**
**Lx-T is well reproduced**
**Luminosity function less well reproduced****:****	****	****	****In-shock cooling? ISM physics?  (probably both are true)**

## Slide 25

## Entropy – final state

**Entropy – final state**

*Thanks to Jon Johansson, *
*CNS, U. of Alberta *

## Galaxies and Stars

**Galaxies and Stars**

**Notes:**
Wherever the cooling time was longer than the Hubble time

## Why don’t we use Gadget2?

**Why don’t we use Gadget2?**

- Simulation time

- Total wallclock

**Final epoch**
**for this project**

*Multiple time-step*
*capability in G2 is*
*very efficient*

*G2 is rather*
*inefficient at high z*

- (Hydra)

## Entropy evolution (slice from simulation)

**Entropy evolution (slice from simulation)**

- Rendered on 13403
- grid.
- Simulation used
- 0.5x109 particles
- (half hydro,
- half dark matter).
- Dynamic range
- ~6000

## Critical Entropy

**Critical Entropy**

- Oh & Benson (2003)

## Heating Sources

- Supernovae: M*/300 1051 
-                         =   31060 ergs  M12(*)

- AGN:  Mbh c2 1.81054  1.6108 vc,3005

- 1 keV/Baryon ~ 21058 ergs/M12(gas)

-    1063 ergs  M12(gas)5/3

## Correlation function of Quasars

**Correlation function of Quasars**

- 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)

- 2dF results (Croom et al 2001)

- Blue=sim

**Notes:**
Above a fixed magnitude limit of B<20.9