PAIR PRODUCTION IN LOW-LUMINOSITY GALACTIC NUCLEI

被引:83
作者
Moscibrodzka, M. [1 ]
Gammie, C. F. [1 ,2 ]
Dolence, J. C. [2 ]
Shiokawa, H. [2 ]
机构
[1] Univ Illinois, Dept Phys, Urbana, IL 61801 USA
[2] Univ Illinois, Dept Astron, Urbana, IL 61801 USA
基金
美国国家科学基金会;
关键词
accretion; accretion disks; black hole physics; Galaxy: center; magnetohydrodynamics (MHD); radiative transfer; SUPERMASSIVE BLACK-HOLE; ELECTRON-POSITRON PAIRS; ACCRETION FLOWS; X-RAY; DOMINATED ACCRETION; A-ASTERISK; M87; SIMULATIONS; EMISSION; PLASMAS;
D O I
10.1088/0004-637X/735/1/9
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Electron-positron pairs may be produced near accreting black holes by a variety of physical processes, and the resulting pair plasma may be accelerated and collimated into a relativistic jet. Here, we use a self-consistent dynamical and radiative model to investigate pair production by gamma gamma collisions in weakly radiative accretion flows around a black hole of mass M and accretion rate (M) over dot. Our flow model is drawn from general relativistic magnetohydrodynamic simulations, and our radiation field is computed by a Monte Carlo transport scheme assuming the electron distribution function is thermal. We argue that the pair production rate scales as r(-6) M-1 (M) over dot(6). We confirm this numerically and calibrate the scaling relation. This relation is self-consistent in a wedge in M, (M) over dot parameter space. If (M) over dot is too low the implied pair density over the poles of the black hole is below the Goldreich-Julian density and gamma gamma pair production is relatively unimportant; if (M) over dot is too high the models are radiatively efficient. We also argue that for a power-law spectrum the pair production rate should scale with the observables LX = X-ray luminosity and M as L-X(2) M-4. We confirm this numerically and argue that this relation likely holds even for radiatively efficient flows. The pair production rates are sensitive to black hole spin and to the ion-electron temperature ratio which are fixed in this exploratory calculation. We finish with a brief discussion of the implications for Sgr A* and M87.
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页数:14
相关论文
共 54 条
[1]   Fast variability of tera-electron volt γ rays from the radio galaxy M87 [J].
Aharonian, F. ;
Akhperjanian, A. G. ;
Bazer-Bachi, A. R. ;
Beilicke, M. ;
Benbow, W. ;
Berge, D. ;
Bernloehr, K. ;
Boisson, C. ;
Bolz, O. ;
Borrel, V. ;
Braun, I. ;
Brown, A. M. ;
Buehler, R. ;
Buesching, I. ;
Carrigan, S. ;
Chadwick, P. M. ;
Chounet, L. -M. ;
Coignet, G. ;
Cornils, R. ;
Costamante, L. ;
Degrange, B. ;
Dickinson, H. J. ;
Djannati-Atai, A. ;
Drury, L. O'C. ;
Dubus, G. ;
Egberts, K. ;
Emmanoulopoulos, D. ;
Espigat, P. ;
Feinstein, F. ;
Ferrero, E. ;
Fiasson, A. ;
Fontaine, G. ;
Funk, Seb. ;
Funk, S. ;
Fuessling, M. ;
Gallant, Y. A. ;
Giebels, B. ;
Glicenstein, J. F. ;
Goret, P. ;
Hadjichristidis, C. ;
Hauser, D. ;
Hauser, M. ;
Heinzelmann, G. ;
Henri, G. ;
Hermann, G. ;
Hinton, J. A. ;
Hoffmann, A. ;
Hofmann, W. ;
Holleran, M. ;
Hoppe, S. .
SCIENCE, 2006, 314 (5804) :1424-1427
[2]   PHOTON BREMSSTRAHLUNG FROM AN EXTREME-RELATIVISTIC ELECTRON GAS [J].
ALEXANIAN, M .
PHYSICAL REVIEW, 1968, 165 (01) :253-+
[3]  
[Anonymous], 1976, The Theory of Photons and Electrons. The Relativistic Quantum Field Theory of Charged Particles with Spin One-half
[4]  
[Anonymous], 1995, BAAS
[5]  
[Anonymous], 1999, Active Galactic Nuclei: From the Central Black Hole to the Galactic Environment
[6]   The influence of magnetic field geometry on the evolution of black hole accretion flows: Similar disks, drastically different jets [J].
Beckwith, Kris ;
Hawley, John F. ;
Krolik, Julian H. .
ASTROPHYSICAL JOURNAL, 2008, 678 (02) :1180-1199
[7]  
BESKIN VS, 1992, ASTRON ZH+, V69, P1258
[8]  
BESKIN VS, 2011, ARXIV11033375
[9]   Understanding the kiloparsec-scale structure of M87 [J].
Bicknell, GV ;
Begelman, MC .
ASTROPHYSICAL JOURNAL, 1996, 467 (02) :597-621
[10]   ELECTROMAGNETIC EXTRACTION OF ENERGY FROM KERR BLACK-HOLES [J].
BLANDFORD, RD ;
ZNAJEK, RL .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1977, 179 (02) :433-456