arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1206.0744astro-ph.HEastro-ph.SRgr-qc
收藏

用质点近似计算白矮星双星的引力波信号

On the point mass approximation to calculate the gravitational wave signal from white dwarf binaries

D. van den Broek, G. Nelemans, M. Dan, S. Rosswog

摘要:

银河系中的双白矮星双星主宰着引力波天空,可以被像LISA这样的仪器探测到。大多数研究都是在假设二元白矮星系统可以用轨道上的两个点质量来代表的情况下计算预期的引力波信号。我们讨论了这种近似对于真实天体物理系统的准确性。对于圆轨道上的非相对论双星,引力波信号可以很容易地计算出来。我们表明,对于这些系统的质点近似是完全合理的,当单个恒星是轴对称的,而不管它们的大小。我们发现,从平滑粒子流体动力学模拟潮汐变形,罗什瓣填充白矮星,包括一种情况下,吸积盘存在时,得到的信号是一致的质点近似。在现实情况下,这种差异通常在1%或更低的水平,从而在二进制的推断参数中产生小的误差。

英文摘要:

Double white dwarf binaries in the Galaxy dominate the gravitational wave sky and would be detectable for an instrument such as LISA. Most studies have calculated the expected gravitational wave signal under the assumption that the binary white dwarf system can be represented by two point masses in orbit. We discuss the accuracy of this approximation for real astrophysical systems. For non-relativistic binaries in circular orbit the gravitational wave signal can easily be calculated. We show that for these systems the point mass approximation is completely justified when the individual stars are axisymmetric irrespective of their size. We find that the signal obtained from Smoothed-Particle Hydrodynamics simulations of tidally deformed, Roche-lobe filling white dwarfs, including one case when an accretion disc is present, is consistent with the point mass approximation. The difference is typically at the level of one per cent or less in realistic cases, yielding small errors in the inferred parameters of the binaries.

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。

↑