论文标题
偏心高质量X射线二进制的演变。 GX 301-2的案例
Evolution of eccentric high-mass X-ray binaries. The case of GX 301-2
论文作者
论文摘要
中子星的形成与强大的天体物理瞬变（例如超新星）有关。在许多情况下，超新星爆炸中的不对称性被认为是中子星的较大速度的原因。我们的目标是研究一个特定的偏心高质量X射线二进制的完整进化历史，该二进制含有中子恒星GX 301-2，并在中子恒星形成时表征了出生踢。我们使用公开可用的恒星进化代码台面从初始阶段发展到核心崩溃场景。我们基于观察结果进行了出生的踢分配，以继续在X射线二进制阶段继续演变，并寻找与GX 301-2的当前观测值相匹配的候选者。我们发现，根据初始质量比的不同，初始质量的范围被限制在$ 30 $ m $ _ \ odot $少于$ 30 $ _ \ odot $左右，因为较高的初始质量很可能最终会产生黑洞。在所研究的完全保守的质量转移情况下，只有当供体仍在其核心燃烧氢时，恒星之间的相互作用是所谓的传质a，能够为GX 301-2产生祖细胞。 Natal Kick研究有利于可变强度的踢球，从而增加了轨道角动量和中子星的自旋之间的倾斜角度。我们得出的结论是，只有狭窄的初始祖细胞参数空间才能产生二进制（例如GX 301-2）。此外，出生踢的强度可以跨越广泛的值，但是在考虑有关二进制系统速度的新数据时，它可能会受到限制。最后，我们得出了预期的二进制数量的比例，例如银河系中的GX 301-2为$ \ sim 6 \ times 10^{ - 5} $，这意味着找到类似于GX 301-2的二进制机会的机会很低。
The formation of neutron stars is associated with powerful astrophysical transients such as supernovae. In many cases, asymmetries in the supernova explosions are thought to be responsible for the large observed velocities of neutron stars. We aim to study the complete evolutionary history of one particular eccentric high-mass X-ray binary containing a neutron star, GX 301-2, and characterize the natal kick at the time of neutron star formation. We used the publicly available stellar-evolution code MESA to evolve binaries from their initial stages until the core-collapse scenario. We incorporated a natal kick distribution based on observations to continue the evolution during the X-ray binary phase and search for candidates matching current observations of GX 301-2. We find that the range of initial masses is constrained to be less than around $30$ M$_\odot$ depending on the initial mass ratio, as higher initial masses will most likely end up producing a black hole. In the completely conservative mass-transfer scenario under study, only is an interaction between the stars when the donor is still burning Hydrogen in its core, the so-called Case A of mass transfer, able to produce progenitors for GX 301-2. The natal kick study favours kicks of variable strength, which in turn increases the tilt angle between the orbital angular momentum and the spin of the neutron star. We conclude that only a narrow initial progenitor parameter space is able to produce a binary such as GX 301-2. Additionally, the strength of the natal kick can span a wide range of values, but it can be constrained when considering new data concerning the systemic velocity of the binary. Finally, we derive the fraction of the expected number of binaries such as GX 301-2 in the Galaxy to be $\sim 6 \times 10^{-5}$, implying a really low chance of finding a binary similar to GX 301-2.
