11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 1 Maxim Barkov MPI-K, Heidelberg, Germany Space Research Institute, Russia, University of Leeds, UK Serguei Komissarov University of Leeds, UK Accretion/Blandford-Znajeck processes and jet formation

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 2 In the last few years we can see significant progress in general relativistic magneto hydrodynamics (GRMHD) simulations of BH accretion systems. It reveals a flow structure that can be decomposed into a disk, corona, disk wind and highly magnetized polar region that contains the jet (De Villiers, Hawley and Krolik 2003; Hawley and Krolik 2006; McKinney and Gammie 2004; McKinney 2005, 2006, 2007; McKinney and Balndford 2009; Shibata, Sekiguchi and Takahashi, 2007, Barkov and Komissarov 2008, 2010, Barkov and Baushev 2011). Blandford-Znajek mechanism

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 3

11/01/2016 Setup (Barkov & Komissarov 2008a,b) (Komissarov & Barkov 2009) black hole M=3M sun a=0.9 Uniform magnetization R=4500km  = 4x x10 28 Gcm -2 outer boundary, R= 2.5x10 4 km free fall accretion (Bethe 1990) 2D axisymmetric GRMHD; Kerr-Schild metric; Realistic EOS; Neutrino cooling; Starts at 1s from collapse onset. Lasts for < 1s Rotation: r c =6.3x10 3 km l 0 = cm 2 s -1 III. Numerical simulations 4 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 Free fall model of collapsing star (Bethe, 1990)‏ radial velocity: mass density: accretion rate: Gravity: gravitational field of Black Hole only (Kerr metric); no self-gravity; Microphysics: neutrino cooling ; realistic equation of state, (HELM, Timmes & Swesty, 2000); dissociation of nuclei (Ardeljan et al., 2005); Ideal Relativistic MHD - no physical resistivity (only numerical); 5 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 magnetic field lines, and velocity vectors unit length=4.5km t=0.24s Model:A C 1 =9; B p =3x10 10 G log 10  (g/cm 3 ) log 10 P/P m log 10 B  /B p 6 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 magnetic field lines, and velocity vectors unit length=4.5km t=0.31s Model:A C 1 =9; B p =3x10 10 G log 10  (g/cm 3 ) 7 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 Model:A C 1 =9; B p =3x10 10 G log 10  (g/cm 3 ) magnetic field lines 8 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 Model:C C 1 =3; B p =10 10 G velocity vectors log 10 P/P m 9 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 Jets are powered mainly by the black hole via the Blandford-Znajek mechanism !! No explosion if a=0; Jets originate from the black hole; ~90% of total magnetic flux is accumulated by the black hole; Energy flux in the ouflow ~ energy flux through the horizon (disk contribution < 10%); Theoretical BZ power: Model: C 10 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 1/50 of case a= Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

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11/01/ Variable Galactic Gamma-Ray Sources, Heidelberg, Germany

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 14 Different magnetic field topologies: Dipole, quadruple 1 and quadruple 2. The initial conditions consist of an equilibrium torus (Fishbone and Moncrief 976; Abramowicz et al. 1978; Komissarov 2006), which is a "torus" of plasma with a black hole at the center. The value of the specific angular momentum of matter and angular momentum of BH ‘a’ determines the total effective potential.

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 15 Magnetic flux Ψ time evolution Time evolution of magnetic flux of model Quadruple 2 on horizon, t= sec -- solid, t= sec -- dashed, t= sec -- doted, t= sec -- three dots dashed. Time evolution of magnetic flux of Dipole model on radius r=4.7 r g left panel and on horizon central panel, t= sec -- solid, t= sec -- dashed, t= sec -- dot dashed, t= sec -- doted, t=0.346 sec -- three dots dashed.

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 16 Dipole Quadruple 1 Quadruple 2 Radial component of magnetic field.

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 17 Quadruple 2. Radial component of magnetic field.

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 18 a=0a=0.9 Flux of matter (MA) - bottom panels and electromagnetic (EM) - up panels per radian depends on θ and time on radius R=180 r g. In our simulations up to ½ of initial electromagnetic flux are transformed to non-relativistic hot wind though numerous shock waves. It can supply hot corona in such objects as SS433.

11/01/2016 Variable Galactic Gamma-Ray Sources, Heidelberg, Germany 19 Lorentz factor Distribution of Lorentz factor and magnetic lines for time sec. Cooling case provides most stable and powerful outflow. The Lorentz factor achieves Γ≤ 4.5 (numerical restriction) Modified coolingNo coolingCooling