Angular Size of Radio Stars
Angular Size of Radio Stars
复制标题
射电星的角大小
作者：
V. Slish
众所周知，存在着许多角延伸小于1″的射电源。它们中的一些被认为是类似恒星的物体，因此它们被称为射电星。其中包括3C-48、3C-119、3C-147、3C-273、3C-286。它们的非热谱和相当强的线偏振的证据表明射电辐射的同步辐射机制。Twiss 2、Razin 3和Le Roux 4已经表明，相对论电子对同步辐射的自吸收必须发生在频率f <f1，f1处，这取决于相对论电子浓度、磁场的法向分量H、射电辐射的光谱指数α（光谱的形式为S（f）<$f-a）以及射电辐射区域的线性尺寸。在f1以下的频率上，射电源的辐射谱为S（f）= f2.5，无论α是多少，f1都是射电源的最大通量密度出现的频率。
THE existence of a number of radio sources with an angular extension less than 1″ is well known1. Some of them were identified with star-like objects and therefore they are referred to as radio stars. Among these are 3C-48, 3C-119, 3C-147, 3C-273, 3C-286. Their non-thermal spectra and the evidence of a rather strong linear polarization suggest the synchrotron mechanism of radio emission. Twiss2, Razin3, and Le Roux4have shown that a self-absorption of synchrotron radiation by relativistic electrons must occur at frequenciesf<f1,f1depending on relativistic electrons concentration, normal component of magnetic fieldH⊥, spectral index of radio emission α (the spectrum being of the formS(f) ∝f−a), and on linear dimension of radio-emitting region. At frequencies belowf1the spectrum of radio emission isS(f) ∝f2.5whatever α is, thusf1is a frequency where maximum flux density of a radio source occurs.