arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0806.0824astro-ph
收藏

脉冲形状模型对中子星XTE J1814-338性质的约束

Constraints on the Properties of the Neutron Star XTE J1814-338 from Pulse Shape Models

Denis A. Leahy, Sharon M. Morsink, Yi-Ying Chung, Yi Chou

摘要:

对XTE J1814-338的吸积动力(非X射线爆发)脉动进行了模拟,以确定中子星参数及其不确定性。该模型是一个旋转的圆形热点,包括:(1)各向同性的黑体光谱分量;(2)各向异性的康普顿光谱分量;(3)相对论性时间延迟和光弯曲;(4)恒星由于旋转而形成的扁球形。该模型是与数据一致的最简单的可能模型。模型的最佳拟合参数有利于刚性状态方程,这可以从质量半径图中的3-sigma允许区域中看出。我们分析了2003年突出的23天期间的所有数据,并分别分析了突出的2天的数据。这两种情况下允许的质量半径区域只允许比状态方程APR更严格的状态方程(EOS)(Akmal et al. 1998),与脉冲星NGC 6440 B的大质量一致(Freire et al. 2008)。通过该分析推断的刚性EOS与从SAX J1808的类似分析推断的软EOS不兼容。

英文摘要:

The accretion-powered (non-X-ray burst) pulsations of XTE J1814-338 are modeled to determine neutron star parameters and their uncertainties. The model is a rotating circular hot spot and includes: (1) an isotropic blackbody spectral component; (2) an anisotropic Comptonized spectral component; (3) relativistic time-delays and light-bending; and (4) the oblate shape of the star due to rotation. This model is the simplest possible model that is consistent with the data. The resulting best-fit parameters of the model favor stiff equations of state, as can be seen from the 3-sigma allowed regions in the mass-radius diagram. We analyzed all data combined from a 23 day period of the 2003 outburst, and separately analyzed data from 2 days of the outburst. The allowed mass-radius regions for both cases only allow equations of state (EOS) that are stiffer than EOS APR (Akmal et al. 1998), consistent with the large mass that has been inferred for the pulsar NGC 6440B (Freire et al. 2008). The stiff EOS inferred by this analysis is not compatible with the soft EOS inferred from a similar analysis of SAX J1808.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑