Bucciantini 2007 伽玛暴的磁星模型

主要内容:
认为磁星在诞生的时候可以产生长伽玛暴的喷流。

精彩摘抄:


文章信息:

arXiv:0707.2100 [ps, pdf, other]

Title: Relativistic Jets and Long-Duration Gamma-ray Bursts from the Birth of Magnetars

Authors: N. Bucciantini (1), E. Quataert (1), J. Arons (1), B.D. Metzger (1), Todd A. Thompson (2) ((1)Astronomy Department, UC Berkeley, (2)Department of Astrophysical Sciences, Princeton)

Comments: 5 pages, 3 figures, submitted to MNRAS letter, presented at the conference "Astrophysics of Compact Objects", 1-7 July, Huangshan, China

Subjects: Astrophysics (astro-ph)

We present time-dependent axisymmetric magnetohydrodynamic simulations of the interaction of a relativistic magnetized wind produced by a proto-magnetar with a surrounding stellar envelope, in the first ~10 seconds after core collapse. We inject a super-magnetosonic wind with \dot E = 10^{51} ergs/s into a cavity created by an outgoing supernova shock. A strong toroidal magnetic field builds up in the bubble of plasma and magnetic field that is at first inertially confined by the progenitor star. This drives a jet out along thepolar axis of the star, even though the star and the magnetar wind are each spherically symmetric. The jet has the properties needed to produce a long-duration gamma-ray burst (GRB). At ~5 s after core bounce, the jet has escaped the host star and the Lorentz factor of the material in the jet at large radii ~10^{11} cm is similar to that in the magnetar wind near the source. Most of the spindown power of the central magnetar escapes via the relativistic jet. There are fluctuations in the Lorentz factor and energy flux in the jet on ~ 0.01-0.1 second timescale. These may contribute to variability in GRB emission (e.g., via internal shocks).