Radiation-MHD Simulations of Black Hole Accretion Flows & Outflows

Transcription

1 Radiation-MHD Simulations of Black Hole Accretion Flows & Outflows clumpy outflow jet accretion disk Ken OHSUGA (NAOJ)

2 WHY RADIATION-MHD? Disk viscosity is magnetic origin. Dissipation of the magnetic energy heats up the gas. Difference of the radiative cooling rate leads to the difference of the disk structure (thick or thin, hot or cold). Radiation- and/or magnetic pressusure drive jets and disk outflows. Clumpy, time-dependent outflow is produced by thermal instability (that is, radiative cooling). Performing radiation-mhd simulations, we investigate the inflow-outflow structure.

3 BASIC EQUATIONS OF RADIATION-MHD ρ + (ρv) =0 t (ρv) + ρvv BB t 4π e t E 0 t = p + B 2 8π + (ev) = p v + 4π c 2 ηj2 4πκB + cκe 0 + χ c F 0 ρ ψ + (E 0 v)= F 0 v : P 0 +4πκB cκe 0 B t = v B 4πc ηj J = 4π c B RHD terms MHD terms

4 NUMERICAL METHOD Cylindrical coordinate (r, ϕ, z); r=2-100rs, z=0-100rs Axisymmetry & Mid-plane Symmetry Initial Conditions & density parameter ρ0[g/cm3]=1.0 BH Torus Magnetic Fields No disk initially! -Rotating torus (plasma-beta=100, closed poloidal magnetic fields; Bϕ=0) -We set the density parameter, ρ0 (density at the center of the torus). Super- Eddington Flow Standard disk RIAF

5 SUPER-EDDINGTON FLOWS ρ/ρ0, [ρ0=1.0 g cm -3 ] Radiation-pressure supported disk + radiatively-driven jet -Mdot~60Ledd/c 2 -Lbol Ledd -Ltrap Ledd MBH=10Msun Ohsuga et al. 2009, PASJ, 61, L7; Ohsuga, Mineshige 2011, ApJ, 726, 2

6 SUPER-EDDINGTON FLOWS ρ/ρ0, [ρ0=1.0 g cm -3 ] Radiation-pressure supported disk + radiatively-driven jet -Mdot~60Ledd/c 2 -Lbol Ledd -Ltrap Ledd MBH=10Msun Ohsuga et al. 2009, PASJ, 61, L7; Ohsuga, Mineshige 2011, ApJ, 726, 2

7 STANDARD DISK & RIAF ρ/ρ0, [ρ0=10-4 g cm -3 ] ρ/ρ0, [ρ0=10-8 g cm -3 ] Lbol~10-4 Ledd, Mdot~10-3 Ledd/c 2 Cold, thin disk L~10-12 Ledd, Mdot~10-5 Ledd/c 2 Hot, thick disk & magnetic jet MBH=10Msun

8 STANDARD DISK & RIAF ρ/ρ0, [ρ0=10-4 g cm -3 ] ρ/ρ0, [ρ0=10-8 g cm -3 ] Lbol~10-4 Ledd, Mdot~10-3 Ledd/c 2 Cold, thin disk L~10-12 Ledd, Mdot~10-5 Ledd/c 2 Hot, thick disk & magnetic jet MBH=10Msun

9 STANDARD DISK & RIAF ρ/ρ0, [ρ0=10-4 g cm -3 ] ρ/ρ0, [ρ0=10-8 g cm -3 ] Lbol~10-4 Ledd, Mdot~10-3 Ledd/c 2 Cold, thin disk L~10-12 Ledd, Mdot~10-5 Ledd/c 2 Hot, thick disk & magnetic jet MBH=10Msun

10 Super-Eddington (Slim) type Standard type RIAF type Radiation Energy & Magnetic Fields Normalized Densiy Our RMHD simulations succeeded in reproducing three types of flows (Super-Eddington, standard, RIAF)

11 OBSERVED LUMINOSITY L>20Ledd % $ " Lbol Ledd L Ledd Radiative Flux is mildly collimated, 20 Luminosity is estimated as L>20Ledd for a face-on observer. In contrast, the objects might be observed to be L Ledd, if observer s viewing angle is much larger than 20. " Radiation energy (E0, color) Radiation flux, (F0, vector)

12 RADIATION-MHD JETS Takeuchi, Ohsuga, Mineshige. 2010, PASJ, 62, L43 Our RMHD simulations reveal a new type of jet; Radiatively-accelerated and magnetically collimated jet

13 RADIATION-MHD JETS f z at r = 10 r s [dyn/g] gravity gas radiation Lorentz Radiation force Gravity z/r s Takeuchi, Ohsuga, Mineshige. 2010, PASJ, 62, L43 Our RMHD simulations reveal a new type of jet; Radiatively-accelerated and magnetically collimated jet

14 RADIATION-MHD JETS f r at z = 40 r s [dyn/g] Centrifugal Lorentz gravity centrifugal gas radiation Lorentz r/r s f z at r = 10 r s [dyn/g] gravity gas radiation Lorentz Radiation force Gravity z/r s Takeuchi, Ohsuga, Mineshige. 2010, PASJ, 62, L43 Our RMHD simulations reveal a new type of jet; Radiatively-accelerated and magnetically collimated jet

15 Ohsuga in prep. TIME-DEPENDENT CLUMPY OUTFLOW MBH=10Msun We found time-dependent, clumpy outflows, 20-50, from the super-eddington disks

16 Ohsuga in prep. TIME-DEPENDENT CLUMPY OUTFLOW MBH=10Msun We found time-dependent, clumpy outflows, 20-50, from the super-eddington disks

17 THERMAL INSTABILITY Slightly Dense Region Radiatively Driven Wind Slightly Less-Dense Region Radiative Cooling >> Joule Heating Low Temperature Compress via Gas Pressure Radiative Cooling < Joule Heating High Temperature Low Temperature, High Temperature, High Density Clouds Low Density Region (Tgas~ K, ρ~ g/cm 3 ) (Tgas~10 9 K, ρ<10-15 g/cm 3 )

18 Super-Eddington objects Lbol 10Ledd, Vjet~ c Time-dependent absorbing feature. Lbol Ledd Vout~0.03c-0.1c Log(NH)~23-25 SMBH (10 8 Msun) Luminous Disk (Lbol~Ledd)

19 Super-Eddington objects Lbol 10Ledd, Vjet~ c Time-dependent absorbing feature. Lbol Ledd Vout~0.03c-0.1c Log(NH)~23-25 SMBH (10 8 Msun) Luminous Disk (Lbol~Ledd) Schematic picture for ULXs (Middleton et al. 2011)

20 LIMIT-CYCLE OSCILLATION Ohsuga 2006, ApJ, 640, 923 Lbol~0.2Ledd Lbol~2Ledd Thermal viscous instability induces limit-cycle behavior.

21 LIMIT-CYCLE OSCILLATION Ohsuga 2006, ApJ, 640, 923 Lbol~0.2Ledd Lbol~2Ledd Thermal viscous instability induces limit-cycle behavior.

22 LIMIT-CYCLE OSCILLATION Mdot Our simulations nicely fit the observations of microquasar, GRS Luminosity 1. Luminosity variation 2Ledd 0.2Ledd 2. Timescale~several 10 sec. 3. Intermittent outflow.

23 AGN FEEDBACK Mass supply rate; from host galaxy to galactic center. We find that mass outflowrate can exceed Ledd/c 2, and momentum ejection-rate can exceed Ledd/c. Feedback from the super- Eddington flow would affect the evolution of the host galaxy and might contribute to establish M-σ relation (King 2003).