Radio spectral index of BL Lac objects

作     者：YUAN YuHai FAN JunHui LONG XiaoLi 

作者机构：Center for AstrophysicsGuangzhou University 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2013年第56卷第5期

页      面：1035-1040页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.10633010 and 11173009) the Bureau of Education of Guangzhou Municipality (Grant No.11 Sui-Jiao-Ke) Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(GDUPS)(2009) Yangcheng Scholar Funded Scheme(Grant No.10A027S) the Joint Laboratory for Optical Astronomy of Chinese Academy of Sciences supported by the University of Michigan and the National Science Foundation 

主　　题：galaxies BL Lacs spectral variability parameter time delay 

摘      要：In this paper, the preliminary data from University of Michigan Radio Astronomy Observatory database （UMRAO） are used to discuss the radio spectral index properties of 8 BL Lacs. To do so, we calculated the radio spectral index, a （F oc va）, which was obtained by fitting the averaged flux densities in the bands （4.8 GHZ, 8 GHz, and 14.5 GHz） by binning the original for 7 d. We also calculated the time delay between the averaged lightcurves and the spectral variance. Our calculations and analysis give the following results. 1） The averaged logarithmic flux density at 8 GHz （logF） and the corresponding spectral index （or） have strong correlation for all the BL Lacs; 2） the lightcurves and the spectral variability have the similar profile for all the BL Lacs; 3） the lightcurves delay spectral variability for all sources but PKS 0735＋178, with the delay time ranging from 31 d to 125 d.