INTRA-BINARY SHOCK HEATING OF BLACK WIDOW COMPANIONS
INTRA-BINARY SHOCK HEATING OF BLACK WIDOW COMPANIONS
复制标题
DOI：
10.3847/0004-637x/828/1/7
复制
发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
R. Romani;N. Sanchez
中科院分区：
文献类型：
--
作者：
R. Romani;N. Sanchez
蒸发的双脉冲星的低质量伴星（黑寡妇和类似的）在面对脉冲星的一侧被强烈加热。然而，在高质量的光度和光谱数据中，加热模式与预期的脉冲星直接照明不匹配。在这里，我们探索了一个模型，其中脉冲星功率在加热低质量伴星之前被双星内激波（IBS）拦截。我们开发了一个简单的分析模型，并在流行的“ICARUS”光曲线代码中实现。该模型以风动量比β和伴星风速作为参数化，并假设再处理后的脉冲星风释放出迅速的粒子或辐射来加热伴星表面。我们展示了由这些参数控制的光曲线不对称的有趣范围。该代码还计算了IBS同步加速器发射模式，从而可以模拟黑寡妇x射线光曲线。作为测试，我们将结果应用于PSR J2215+5135高质量的非对称光学光曲线；所得到的拟合在直接加热模型上有了实质性的改进，并产生了与所见一致的x射线光曲线。IBS模型参数表明，在当前损失率下，伴随蒸发具有Myr的特征时间尺度。然而，该模型并不完全令人满意，这表明还有其他未建模的物理效应。
The low-mass companions of evaporating binary pulsars (black widows and similar) are strongly heated on the side facing the pulsar. However, in high-quality photometric and spectroscopic data, the heating pattern does not match that expected for direct pulsar illumination. Here we explore a model where the pulsar power is intercepted by an intra-binary shock (IBS) before heating the low-mass companion. We develop a simple analytic model and implement it in the popular “ICARUS” light curve code. The model is parameterized by the wind momentum ratio β and the companion wind speed , and assumes that the reprocessed pulsar wind emits prompt particles or radiation to heat the companion surface. We illustrate an interesting range of light curve asymmetries controlled by these parameters. The code also computes the IBS synchrotron emission pattern, and thus can model black widow X-ray light curves. As a test, we apply the results to the high-quality asymmetric optical light curves of PSR J2215+5135; the resulting fit gives a substantial improvement upon direct heating models and produces an X-ray light curve consistent with that seen. The IBS model parameters imply that at the present loss rate, the companion evaporation has a characteristic timescale of Myr. Still, the model is not fully satisfactory, indicating that there are additional unmodeled physical effects.