Loeb Abraham
Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540, USA.
Phys Rev Lett. 2003 Aug 15;91(7):071103. doi: 10.1103/PhysRevLett.91.071103.
Gravitationally redshifted absorption lines of Fe XXVI, Fe XXV, and O VIII were inferred recently in the x-ray spectrum of the bursting neutron star EXO 0748-676. We place an upper limit on the stellar magnetic field based on the iron lines. The oxygen absorption feature shows a multiple component profile that is consistent with Zeeman splitting in a magnetic field of approximately (1-2) x 10(9) G and for which the corresponding Zeeman components of the iron lines are expected to be blended together. In other systems, a field strength > or approximately 5 x 10(10) G could induce a blueshift of the line centroids that would counteract gravitational redshift and complicate the derivation of constraints on the equation of state of the neutron star.
最近在爆发中的中子星EXO 0748 - 676的X射线光谱中推断出了铁XXVI、铁XXV和氧VIII的引力红移吸收线。我们基于铁线对恒星磁场设定了一个上限。氧吸收特征显示出一个多成分轮廓，这与在大约(1 - 2)×10⁹ G的磁场中的塞曼分裂一致，并且预计铁线的相应塞曼成分会混合在一起。在其他系统中，场强≥或约为5×10¹⁰ G可能会导致谱线质心的蓝移，这将抵消引力红移，并使推导中子星状态方程的约束条件变得复杂。
