Comprehensive Study of the Blazars from Fermi-LAT LCR: The Log-Normal Flux Distribution and Linear rms–Flux Relation  

作　　者：Na Wang Ting-Feng Yi Liang Wang Li-Sheng Mao Zhi-Yuan Pu Gong-Ming Ning Wei-Tian Huang He Lu Shun Zhang Yu-Tong Chen Liang Dong 

机构地区：[1]Department of Physics,Yunnan Normal University,Kunming 650500,China [2]Guangxi Key Laboratory for the Relativistic Astrophysics,Nanning 530004,China [3]Yunnan Province China-Malaysia HF-VHF Advanced Radio Astronomy Technology International Joint Laboratory,Kunming 650011,China

出　　处：《Research in Astronomy and Astrophysics》2023年第11期90-98,共9页天文和天体物理学研究（英文版）

基　　金：funded by the National Natural Science Foundation of China (grants 12063007 and 11863007)。

摘　　要：Fermi-LAT LCR provides continuous and regularly sampled gamma-ray light curves, spanning about 14 yr, for a large sample of blazars. The log-normal flux distribution and linear rms–flux relation of the light curves for a few Fermi blazars have been examined in previous studies. However, the probability that blazars exhibit the log-normal flux distribution and linear rms–flux relation in their gamma-ray light curves has not been systematically explored.In this study, we comprehensively research the distribution of γ-ray flux and the statistical characteristics on a large sample of 1414 variable blazars from the Fermi-LAT LCR catalog, including 572 FSRQs, 477 BL Lacs, and 365BCUs, and statistically compare their flux distributions with normal and log-normal distributions. The results indicate that the probability of not rejecting log-normal is 42.05% for the large sample, and there is still a 2.05%probability of not rejecting normality, based on the joint of Kolmogorov–Smirnov, Shapiro–Wilk, and Normality tests. We further find that the probability that BL Lacs conform to the log-normal distribution is higher than that of FSRQs. Besides, after removing sources with less than 200 data points from this large sample, a sample of 549blazars, which is still a large sample compared to the previous studies, was obtained. Based on dividing the light curves into segments every 20 points(or 40 points, or one year), we fitted the linear rms–flux relation of these three different sets and found that the Pearson correlation coefficients are all close to 1 for most blazars. This result indicates a strong linear correlation between the rms and the flux of these 549 blazars. The log-normal distribution and linear rms–flux relation indicate that the variability of the γ-ray flux for most blazars is a non-linear and multiplicative process.

关 键 词：(galaxies:)quasars:general (galaxies:)BL Lacertae objects:general galaxies:jets galaxies:active 

分 类 号：P158[天文地球—天文学]