Thermal cyclotron radiation by isolated magnetic white dwarfs and constraints on the parameters of their coronas
Thermal cyclotron radiation by isolated magnetic white dwarfs and constraints on the parameters of their coronas
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DOI：
10.1134/1.1648076
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发表时间：
2004-02
影响因子：
1
通讯作者：
V. Zheleznyakov;S. A. Koryagin;A. V. Serber
中科院分区：
文献类型：
--
作者：
V. Zheleznyakov;S. A. Koryagin;A. V. Serber
本文提出了一种探测和估算磁场约为107 G的孤立白色矮星日冕参数的有效方法。这种方法是基于在电子回旋频率的谐波，这是作为一个偏振的红外过量表现出的日冕等离子体的热辐射的检测。本文计算了偶极磁场作用下白色矮星热日冕热回旋辐射的斯托克斯参数。在白色矮星G99-47（WD 0553+053）的日冕中，发现了一个新的电子密度上限1010 cm −3，其温度为106 K。这一限度比早先从ROSAT X射线观测得出的数值低40倍。随后的红外观测孤立的磁白色矮星的建议，旨在检测其日冕或推导出更好的约束其参数。
An efficient method for the detection and estimation of the parameters of the coronas of isolated white dwarfs possessing magnetic fields of about 107G is tested. This method is based on the detection of thermal radiation of the coronal plasma at harmonics of the electron gyrofrequency, which is manifest as a polarized infrared excess. The Stokes parameters for the thermal cyclotron radiation from the hot corona of a white dwarf with a dipolar magnetic field are calculated. A new upper limit for the electron density, 1010cm−3, in a corona with a temperature of ≳106K is found for the white dwarf G99-47 (WD 0553+053). This limit is a factor of 40 lower than the value derived earlier from ROSAT X-ray observations. Recommendations for subsequent infrared observations of isolated magnetic white dwarfs aimed at detecting their coronas or deriving better constraints on their parameters are presented.