EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE

	EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE
	Yan, DH; Zhang, L; Yuan Q(袁强); Yuan, Q; Fan, ZH; Zeng, HD
刊名	ASTROPHYSICAL JOURNAL
	2013
卷号	765 期号:2 页码:122
关键词	acceleration of particles BL Lacertae objects: individual (Mrk 421) galaxies: active galaxies: jets gamma rays: galaxies radiation mechanisms: non-thermal
英文摘要	We investigate the electron energy distributions (EEDs) and the acceleration processes in the jet of Mrk 421 through fitting the spectral energy distributions (SEDs) in different active states in the frame of a one-zone synchrotron self-Compton model. After assuming two possible EEDs formed in different acceleration models: the shock-accelerated power law with exponential cut-off (PLC) EED and the stochastic-turbulence-accelerated log-parabolic (LP) EED, we fit the observed SEDs of Mrk 421 in both low and giant flare states using the Markov Chain Monte Carlo method which constrains the model parameters in a more efficient way. The results from our calculations indicate that (1) the PLC and LP models give comparably good fits for the SED in the low state, but the variations of model parameters from low state to flaring can be reasonably explained only in the case of the PLC in the low state; and (2) the LP model gives better fits compared to the PLC model for the SED in the flare state, and the intra-day/night variability observed at GeV-TeV bands can be accommodated only in the LP model. The giant flare may be attributed to the stochastic turbulence re-acceleration of the shock-accelerated electrons in the low state. Therefore, we may conclude that shock acceleration is dominant in the low state, while stochastic turbulence acceleration is dominant in the flare state. Moreover, our result shows that the extrapolated TeV spectra from the best-fit SEDs from optical through GeV with the two EEDs are different. It should be considered with caution when such extrapolated TeV spectra are used to constrain extragalactic background light models.
学科主题	Astronomy & Astrophysics
收录类别	SCI
WOS记录号	WOS:000315921500047
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/224425]
专题	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	Yan, DH,Zhang, L,Yuan Q,et al. EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE[J]. ASTROPHYSICAL JOURNAL,2013,765(2):122.
APA	Yan, DH,Zhang, L,袁强,Yuan, Q,Fan, ZH,&Zeng, HD.(2013).EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE.ASTROPHYSICAL JOURNAL,765(2),122.
MLA	Yan, DH,et al."EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE".ASTROPHYSICAL JOURNAL 765.2(2013):122.