Arman Khalatyan AIP 2006 GROUP meeting at AIP

Outline What is AGN? –Scales The model –Multiphase ISM in SPH SFR –BH model Self regulated accretion ?! Galaxy mergers –Setup, resolution, numeric's … Results Prospects

The Scales. A false color composite image of the central parsec of the GC taken by the Very Large Telescope. Old, intermediate mass cool red giants and young massive hot blue stars. Genzel et al. 2003

Scales

Galaxy Model DM Halo-NFW profile Disk – exponential –stellar –gaseous Bulge – Hernquist profile Springel et al. 2005

Model-MULTIPHASE ISM, SFR McKee & Ostriker (1977)

Model-MULTIPHASE ISM, SFR First implementation of two phase ISM was by G.Yepes et al (1997) for Eulerian code. Modified and extended ISM model were implemented using SPH formalism by Springel et al –radiative heating and cooling –cold clouds embedded in an ambient hot medium –star formation –feedback from SN( thermal feedback and cloud evaporation) –Galactic winds and outflows –Metal enrichment

SFR in MULTIPHASE ISM Rates at which the masses of the hot and cold phases evolve can be written: Effective EOS: Density dependence of the SN evaporation SFR: Springel et al 2005 Note:we use q=0.05

“GOLDEN RULE FOR SFR ? ” Kennicut law for sfr: SFR parameters: –t 0 * 2.1 Gyr –A 0 1.0e4 K –T SN 1.0e8 K Springel et al 2005

Cooling function Katz et al. 1996

Cooling function including metals Dopita & Sutherland 2003 x95

Modeling AGN by Bondi(1952) A fraction  of the power generated by the accretion of matter onto the black hole heats the surrounding gas at a rate: The Cooling rate per unit mass of heated gas is: Cattaneo 2006 SPH implementation by Springel et al 2005 Energetic efficiency of black hole accretion 0.1 Hydrogen baryon fraction

The BH model The heating rate per unit mass of the gas depends on three parameters: –the accretion efficiency with respect to the Bondi rate :  –the fraction of the accretion power converted into heat:  –the mass M gas on which the heat is distributed Cattaneo 2006, Springel et al. 2005

Local M  – T equilibrium Black hole – IGM coupling factor: Cattaneo 2006

Parameter tests Simulations was done by GAGDET-2 TreeSPH code. Set of simulations was performed ( ~70 different mergers)

Magorrian relation: M BH - M bulge William C. Keel

Parameter space study Model parameters: –physical: , ,  gas –numerical: M BH0, , NGB, q Toomre

Final BH mass vs  and 

Mbh vs Mgas

Suppression of SFR

COOLING and BH-growth

Gas temperature surrounding BH

MOVIE

Thank You for Your Attention. To be continued…

Next Step: Cosmology Elliptical galaxy N198, Zoomed simulation in box 50Mpc/h with special resolution 1024^3 particles M gas =5.9 1e5 M ⊙ 200 kpc/h Z = 3.7