标题： 脉冲星和磁星中吉赫兹峰谱的热吸收原因 显示英文标题

标题： Thermal absorption as the cause of gigahertz-peaked spectra in pulsars and magnetars

摘要： 我们提出了一种模型，用于解释一些脉冲星和磁星的能谱与大多数脉冲星群体所呈现的幂律能谱之间的偏差。 我们的模型基于如下假设：脉冲星能谱的多样性可以通过脉冲星周围环境中的热自由-自由吸收自然地加以解释。 在此背景下，脉冲星能谱的多样性可以根据吸收介质的形状、密度和温度以及视线方向上的光程来解释。 我们特别关注了射电磁星 SGR J1745-2900（也称为人马座 A* 磁星）的情况，将 2013 年 4 月爆发后脉冲星能谱的快速变化建模为由于磁星爆发期间喷出的电子物质对射电辐射的自由-自由吸收所致。 喷出物随着时间扩展，因此吸收率下降且能谱形状发生变化，导致峰值频率向较低的射电频率偏移。 在吸收介质的假设下，我们还讨论了双星脉冲星 B1259-63 的能谱行为与孤立脉冲星的能谱特征之间的相似性。 显示英文摘要

摘要： We present a model that explains the observed deviation of the spectra of some pulsars and magnetars from the power-law spectra which are seen in the bulk of the pulsar population. Our model is based on the assumption that the observed variety of pulsar spectra can be naturally explained by the thermal free-free absorption that takes place in the surroundings of the pulsars. In this context, the variety of the pulsar spectra can be explained according to the shape, density and temperature of the absorbing media and the optical path of the line-of-sight across that. We have put specific emphasis on the case of the radio magnetar SGR J1745-2900 (also known as Sgr A* magnetar), modeling the rapid variations of the pulsar spectrum after the outburst of Apr 2013 as due to the free-free absorption of the radio emission in the electron material ejected during the magnetar outburst. The ejecta expands with time and consequently the absorption rate decreases and the shape of the spectrum changes in such a way that the peak frequency shifts towards the lower radio frequencies. In the hypothesis of an absorbing medium, we also discuss the similarity between the spectral behaviour of the binary pulsar B1259-63 and the spectral peculiarities of isolated pulsars.