ADIOS Revisited Mitch Begelman JILA, University of Colorado
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Revisited ADIOS Revisited Mitch Begelman JILA, University of Colorado Started: 1987 AAS, Pasadena ROGER’S WRONGEST PAPER? Started: 1998 AAS, San Diego HOPEFULLY LESS WRONG The ADIOS model addresses a fundamental problem in accretion theory… HOW DOES ROTATING GAS ACCRETE IF IT CAN’T RADIATE EFFICIENTLY? THE PROBLEM: ACCRETION REQUIRES TORQUE + TORQUE TRANSPORTS ENERGY Angular Momentum Flux: G Torque G ~ M outward Energy Flux: G outward IN A THIN ACCRETION DISK: Local rate of energy release: GM M 2R G Local rate of dissipation: GM 3 M 2R 2/3 of energy dissipated at R transported from <R by viscous torque IN A RADIATIVELY INEFFICIENT ACCRETION FLOW: Energy Transport: G ~ M B G 2 v B h 0 2 Bernoulli Function Energy transport from small R by torque unbinds gas at large R 1 g of gas accreting at r ~ m can liberate 1 kg of gas at r ~ 1000 m • Torque a “conveyor belt” for liberated energy • Flow must find a way to limit energy transported outward from smaller r ADIOS = ADIABATIC INFLOW-OUTFLOW SOLUTION (Blandford & Begelman 99) – Mass loss or circulation – Small fraction of supplied mass reaches BH THE ADIOS MODEL Inflow B 0 n M R Ang.Mom. 0 n 1 Energy R Mass Energy Ang. Mom. Mass Outflow or circulation B0 R1/ 2 1 SELF-SIMILAR DISK WINDS Disk: Viscous flow with B < 0 Entropy increases at diskwind interface Wind: Inviscid outflow with B < 0 Jet: Evacuated cone High shear across wind No internal mixing across streamlines Huge parameter space of solutions Blandford & Begelman 2004 SELF-SIMILAR DISK WINDS Disk: Viscous flow with B < 0 Entropy increases at diskwind interface Wind: Inviscid outflow with B < 0 Blandford & Begelman 2004 SELF-SIMILAR DISK WINDS Disk: Viscous flow with B < 0 Entropy increases at diskwind interface Wind: Inviscid outflow with B < 0 High shear across wind No internal mixing across streamlines Huge parameter space of solutions 0<n<1 Blandford & Begelman 2004 SIMULATIONS SHOW MORE RESTRICTIVE BEHAVIOR... n ~1 Hawley & Balbus 02 M in M R M out M net M in M out Lindner, Milosavljevic, Couch, and Kumar 2009, preprint Lindner, Milosavljevic, Couch, and Kumar 2009, preprint TWO-ZONE ADIOS MODEL Inflow B 0 M R n Ang.Mom. 0 n 1 Energy R Exchange: Mass Energy Ang. Mom. R1/ 2 1 Mass Outflow B0 AVERAGE OVER STREAMLINES CONSERVE ENERGY, ANG. MOM. IN EACH ZONE CONSERVE EXCHANGED ENERGY, ANG. MOM. TWO-ZONE ADIOS MODEL Inflow B 0 M ~ R n 1 Exchange: Mass Energy Ang. Mom. Ang.Mom. Energy R M TOTAL POWER AVAILABLE R FRACTION 1 Mass Outflow B0 NO SOLUTION UNLESS: INCLUDE CENTRAL ENERGY SOURCE R1/ 2 n≈1 DRIVES OUTFLOW, 1 FLOWS THRU DISK BREEZE MODELS Bound, viscous inflow No slow solution possible Unbound, very slow outflow Viscous stress important in outflow Thin disk limit, a=0 Stress vanishes in outflow Marginally bound inflow BREEZE MODELS Bound, viscous inflow Unbound, very slow outflow Viscous stress important in outflow WIND MODELS Bound, viscous inflow Unbound, dynamical outflow Viscous stress unimportant in outflow PREDICTION: 2 Lout ~ Lin 3 ( if ang. mom. transfer local) WIND MODELS OUTFLOW CAN BE SUBSONIC OR SUPERSONIC … BUT REQUIRES HIGH ENERGY INPUT () SUBSONIC CONCLUSIONS • A new type of ADIOS solution – “well-mixed” outflow • Explains Ṁ~R scaling • Inflow and outflow exchange M, L, but little E • Energy to drive outflow comes from center – Total energy supply |Eacc|Ṁacc~Ṁ/R – Fraction to outflow, 1- carried outward by inflowing gas – Details of inner accretion flow determine , • Applications: SS433, Galactic Center … Started: 1987 AAS, Pasadena Gestation period: 4 months Started: 1998 AAS, San Diego Gestation period: 7 months Started: 1998 Texas Symposium, Paris Gestation period: 5 years Started: 1999 KITP BH Meeting, Santa Barbara Gestation period: 8 years Started: 2009 BlandfordFest, Stanford 0.2327v1 [astro-ph.HE] 17 Oct 20?? Gestation period: ??
