The effects of vertical outflows on disk dynamos

被引：23

作者：

Bardou, A ^{[1
]}

von Rekowski, B

Dobler, W

Brandenburg, A

Shukurov, A

机构：

[1] Newcastle Univ, Dept Math, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England

[2] NORDITA, DK-2100 Copenhagen, Denmark

来源：

ASTRONOMY & ASTROPHYSICS | 2001年 / 370卷 / 02期

关键词：

accretion; accretion disks; magnetic fields; galaxies : magnetic fields;

D O I：

10.1051/0004-6361:20010267

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We consider the effect of vertical outflows on the mean-field dynamo in a thin disk. These outflows could be due to winds or magnetic buoyancy. We analyse both two-dimensional finite-difference numerical solutions of the axisymmetric dynamo equations and a free-decay mode expansion using the thin-disk approximation. Contrary to expectations, a vertical velocity can enhance dynamo action! provided the velocity is not too strong. In she nonlinear regime this can lead to super-exponential growth of the magnetic field.

引用

页码：635 / 648

页数：14

共 31 条

[1] Instability, turbulence, and enhanced transport in accretion disks [J].

Balbus, SA ;

Hawley, JF .

REVIEWS OF MODERN PHYSICS, 1998, 70 (01) :1-53

[2] Constraints on the magnitude of α in dynamo theory [J].

Blackman, EG ;

Field, GB .

ASTROPHYSICAL JOURNAL, 2000, 534 (02) :984-988

[3]

BRANDENBURG A, 1993, ASTRON ASTROPHYS, V271, P36

[4] DYNAMO-GENERATED TURBULENCE AND LARGE-SCALE MAGNETIC-FIELDS IN A KEPLERIAN SHEAR-FLOW [J].

BRANDENBURG, A ;

NORDLUND, A ;

STEIN, RF ;

TORKELSSON, U .

ASTROPHYSICAL JOURNAL, 1995, 446 (02) :741-754

[5]

BRANDENBURG A, 2000, UNPUB

[6]

BRANDENBURG A, 2001, IN PRESS A A

[7]

BRANDENBURG A, 2001, IN PRESS APJ

[8]

Brandenburg A., 1998, Theory of Black Hole Accretion Disks, P61

[9] Magnetic field bending in accretion discs with dynamos [J].

Campbell, CG ;

Papaloizou, JCB ;

Agapitou, V .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1998, 300 (01) :315-320

[10] Launching of accretion disc winds along dynamo-generated magnetic fields [J].

Campbell, CG .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1999, 310 (04) :1175-1184

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