Feedback from Momentum-Driven Winds Eliot Quataert (UC Berkeley) w/ Norm Murray & Todd Thompson NGC 3079 w/ HST

Outline Context: Thermally-Driven Galactic Winds (supernovae) Momentum-Driven Galactic Winds (radiation pressure) –Three Eddington Limits –Cosmological Speculation: Self-regulated Starbursts and BH Growth

The Standard Lore: Supernovae Driven Galactic Winds Strickland & Stevens (2000) Hot gas blown out by collective effects of SN efficiency uncertain because most of SN energy deposited in ISM may be radiated away simulations suggest that little mass is blown away because SN vent their energy by ‘blowing out’ of the galactic plane

Interaction of Cold Gas & Hot Wind Poludnenko et al Cold Clouds destroyed by hot wind Results probably underestimate destruction of cold gas (e.g., no evaporation) unclear how to account for outflowing cold gas seen in absorption in LBGs, ULIRGs, local starbursts, etc.

Radiation Pressure Driven Winds Dust absorbs the radiation produced by starbursts or AGN Dust collisionally coupled to the gas: mfp ~ 10 a 0.1 n 1 pc Momentum-driven wind: Efficient mechanism for blowing cold dusty gas out of a galaxy (i.e, couples to the phase of the ISM with most of the mass)

The Eddington Limit(s) To blow gas out of galaxy, luminosity must exceed L EDD Optically Thick Clouds of Gas: Mass M c Area A c F rad classic optically thin L EDD M c /A c ~  c R c ~ m p N H 2  2 = GM(r)/r ~ const

Absorption-line Probes of Outflowing Cold Gas in Local Starbursts Data from Heckman et al. (2000) Eddington Limit

Terminal Velocity of Outflowing Cold Gas Data from Martin (2004) V term ~ 2.5  ~ V esc ULIRGs LIRGs Dwarfs Hot gas inferred to have V hot ~ 500 km/s independent of  Ram pressure in hot wind V term ~ V hot ~ 500 km/s L ~ L EDD  V term ~ 

Terminal Velocity of Outflowing Cold Gas Data from Martin (2004) V term ~ 2.5  ~ V esc ULIRGs LIRGs Dwarfs interesting implications for enriching IGM, Ly-  forest, etc. small galaxies may preferentially lose more of their mass

The Optically Thick ‘Shell’ Limit (Galaxy Opaque Along Most Lines of Sight) M(r) = 2  2 r/G M g = fM For L > L M momentum injection is sufficient to blow away all of the gas in a galaxy Conjecture: L M is an upper limit to the luminosity of a starburst or AGN: systems that reach L M self-regulate & L does not increase further

The Maximum Luminosity of Starbursts

Decay of Starbursts Based on Models of Bruzual & Charlot (2003)

The Origin of the Faber-Jackson Relation? L  L M   4 in high z starbursts such as LBGs, Scuba sources, … (probably in mergers) L  L FJ as starburst fades

Black Holes Efficient angular momentum transport in mergers can trigger BH growth and AGN activity Dust present outside R sub ~ 1 L 46 pc If L  L M, AGN can blow dusty gas out of its vicinity, controlling its own fuel supply 1/2 Josh Barnes

The Maximum Luminosity of Quasars  from width of OIII line in NLR

The Origin of the M-  Relation? Inside R sub ~ 1 L 46 pc, dust destroyed ‘Normal’ optically thin Eddington limit applies With sufficient fuel supply, L ~ L EDD  M BH As BH grows, L  L M   4 1/2

Summary Radiation Pressure can drive powerful galactic winds and is an important feedback mechanism in the growth of galaxies & BHs Can account for properties of cold outflowing gas seen in starbursts V term ~  may modify picture of metal enrichment and impact of galactic winds on Ly-  forest (winds less destructive …) L M ~ 3x10 46  200 ergs/s: maximum luminosity of Galaxies & BHs? –may regulate mass of *s in early type galaxies (FJ) & mass of their central BHs (M BH -  ) 4