Thin accretion disc with a corona in a central magnetic field

被引:1
作者
Khajenabi, Fazeleh [2 ]
Shadmehri, Mohsen [1 ,3 ]
Dib, Sami [4 ,5 ]
机构
[1] Dublin City Univ, Sch Math Sci, Dublin 9, Ireland
[2] Univ Coll Dublin, Sch Math Sci, Dublin 4, Ireland
[3] Ferdowsi Univ Mashhad, Sch Sci, Dept Phys, Mashhad, Iran
[4] Lebanese Univ, Fac Sci, Dept Phys, Beirut, Lebanon
[5] CEA Saclay, Serv Astrophys, DSM, DAPNI,SAp, F-91191 Gif Sur Yvette, France
关键词
accretion discs; stars : magnetic field; stars : neutron;
D O I
10.1007/s10509-008-9766-y
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We study the steady-state structure of an accretion disc with a corona surrounding a central, rotating, magnetized star. We assume that the magneto-rotational instability is the dominant mechanism of angular momentum transport inside the disc and is responsible for producing magnetic tubes above the disc. In our model, a fraction of the dissipated energy inside the disc is transported to the corona via these magnetic tubes. This energy exchange from the disc to the corona which depends on the disc physical properties is modified because of the magnetic interaction between the stellar magnetic field and the accretion disc. According to our fully analytical solutions for such a system, the existence of a corona not only increases the surface density but reduces the temperature of the accretion disc. Also, the presence of a corona enhances the ratio of gas pressure to the total pressure. Our solutions show that when the strength of the magnetic field of the central neutron star is large or the star is rotating fast enough, profiles of the physical variables of the disc significantly modify due to the existence of a corona.
引用
收藏
页码:251 / 260
页数:10
相关论文
共 41 条
[1]  
ALY JJ, 1980, ASTRON ASTROPHYS, V86, P192
[2]  
ALY JJ, 1990, ASTRON ASTROPHYS, V227, P473
[3]   Accretion disc evolution in single and binary T Tauri stars [J].
Armitage, PJ ;
Clarke, CJ ;
Tout, CA .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1999, 304 (02) :425-433
[4]   A POWERFUL LOCAL SHEAR INSTABILITY IN WEAKLY MAGNETIZED DISKS .1. LINEAR-ANALYSIS [J].
BALBUS, SA ;
HAWLEY, JF .
ASTROPHYSICAL JOURNAL, 1991, 376 (01) :214-222
[5]   COMPTON HEATED WINDS AND CORONAE ABOVE ACCRETION DISKS .2. RADIATIVE-TRANSFER AND OBSERVABLE CONSEQUENCES [J].
BEGELMAN, MC ;
MCKEE, CF .
ASTROPHYSICAL JOURNAL, 1983, 271 (01) :89-112
[6]  
BURM H, 1986, ASTRON ASTROPHYS, V165, P120
[7]  
BURM H, 1988, ASTRON ASTROPHYS, V192, P165
[8]   Disc structure around strongly magnetic accretors: a full disc solution with buoyancy diffusivity [J].
Campbell, CG ;
Heptinstall, PM .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1998, 301 (02) :558-568
[9]   Measurements of accretion disc corona size in LMXB: consequences for comptonization and LMXB models [J].
Church, MJ ;
Balucinska-Church, A .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2004, 348 (03) :955-963
[10]  
CHURCH MJ, 1995, ASTRON ASTROPHYS, V300, P441