Doppler Factor Estimation of Blazars Based on the Shortest Variability Timescale
The Doppler factor is of significant importance for studying the intrinsic radiation characteristics of blazars.We collected 15 GHz band photometric data from the Owens Valley Radio Observatory for 988 blazars over a period of four years(20072011),with measurements taken twice a week on average.Three types of the shortest radio variability timescales were defined,and the brightness temperature and Doppler factor for each source were estimated.The KolmogorovSmirnov(KS)test and the Wilcoxon ranksum test were used to compare the distributions of brightness temperature and Doppler factors between the BL Lacertae(BL Lac)object subsample and the flatspectrum radio quasar(FSRQ)subsample.The results indicate that flatspectrum radio quasars,on average,have higher radio brightness temperatures and optical Doppler factors.
万方数据
维普
