类星体X射线辐射的性质

本文对247个类星体的X射线性质进行了统计分析,这些X射线资料是由爱因斯坦卫星在0.5—4.5keV的能带内观测到的。主要结果是:在各种视亮度和红移(或距离)的已知1619个类星体中,都有百分比相近的部分为X射线源。Ⅰ型Seyferc星系的发射线H_β与OⅢ]的等值宽度比R_EW同X射线光度L_x强相关,这可作为Ⅰ型Seyfert星系的X射线光度的一个新指标。光学辐射以及2.5GHz以上的高频射电辐射都同X射线辐射相关,说明这三种辐射的区域依次相邻而且机制也相似。色指数U-B和B-V都同X射线辐射不相关,但U-B同B-V弱相关。 

THE PROPERTIES OF X-RAY RADIATION OF QUASARS

Statistical analysis of the X-ray prop erties of 247 quasars in the 0.5-4.5 keVband observed from the Einstein Satellite,are carried out in this paper which is one of a series of papers devoting to the study of X-ray quasars and active galactic nuclei.The following main results are found:1.Among all the 1619 known quasars of various apparent magnitudes and red-shifts (or distances),those detected as X-ray sources are of nearly equal percentages.2.There exists a weak correlation between the optical radiation and the X-ray radiation.The correlation coefficients in some cases are shown in Table 1,which shows clearly that the radio emission with frequencies higher than 2.5 GHz correlates strongly with X-ray radiation,implying that the emitting regions in these three bands (optical,high frequency radio anl X-ray bands) are close to one another in order and that their emitting mechanisms are similar.3.There is a strongly correlation between the radio R_EW of equivalent widths of the emission lines H_β and OIII],and the X-ray luminosity L_x (0.5-4.5 keV) for type I Seyfert galaxies (Fig.10),whose properties are similar to those of radio-quiet quasars.We propose this correlation equation (5.2)] as a new X-ray luminosity indicator for type I Seyfert galaxies.4.Neither the color index U-Bnor B Vcorrelates with X-ray radiation,but U-Bcorrelates with B-Vweakly.Acknowledgement: One of the authors (H.S.Yang) thanks Dr.G.Burbidge,Director of Kitt Peak National Observatory (Tucson,Arizona,U.S.A.),for many helpful discussions during his stay at KPNOwhere part of this work was done.Yang thanks also Mr.J.Wagner for help in using computer.