2016/03/04 by H. Z. Li, Y. G. Jiang, D. F. Guo +2 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Crystallography and Radiation Phenomena #Flux (metallurgy) #Radio signal #Radio spectrum #Radio wave #Radioactive Decay and Measurement Techniques #Scattering #Synchrotron #Synchrotron radiation #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1088/1538-3873/128/965/074101
22 pages, 7 figures, accepted for publication in Publications of the Astronomical Society of the Pacific
arxiv created 2016/03/04 · openalex publication_date 2016/06/13 · arxiv updated 2016/06/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have assembled the historical variability data of Mrk 421 at radio 15 GHz, X-ray, and γ -ray bands, spanning about 6.3, 10.3, and 7.5 yr, respectively. We analyzed the variability by using three methods. The results indicated that there is a period of 287.6 ± 4.4 days for 15 GHz, 309.5 ± 5.8 days for X-ray and 283.4 ± 4.7 days for γ -ray, respectively. This period can be reasonably explained by the nonballistic helical motion of the emitting material. The correlation analysis suggested that the variabilities of radio 15 GHz, X-ray, and γ -ray are remarkably correlated, and the emission of radio 15 GHz lags behind that of X-ray, and the X-ray flux lags behind the γ -ray. This suggests that the γ -ray is derived from inverse-Compton (IC) scattering of the synchrotron photons, supporting the synchrotron self-Compton (SSC) model. Moreover, the time delay between different wavebands could be explained by the shock-in-jet models, in which a moving emission region produces the radio to γ -ray activity, implying that the emission region of γ -ray is closer to the center than ones of X-ray and radio emission.