Study On High-energy Emission Of High-redshift Blazars PKS 0106+01

High-redshift blazars are one of the most powerful sources in the universe and?-ray flare carries crucial information about their relativistic jets.The multi-band spectral energy distributions(SEDs)of high-redshift blazars can shift to smaller frequencies compared to the general low-redshift blazars,resulting in the major characteristics of these high-redshift blazars is that they have softer?-ray spectra.?-ray photons from high-redshift blazars will interact with low-energy extragalac-tic background light(EBL),and be absorbed by producing electron-positron pairs.And in the source region,the difference of high-energy radiation mechanisms or the absorption in the emission region will affect the shape of the?-ray energy spec-trum.This paper focuses on the analysis of fast variability and energy spectrum of?-ray emission of the high-redshift blazar PKS 0106+01(z=2.099).We consider the Fermi-LAT data for PKS 0106+01 nearly a decade from August 4,2008 to May 15,2018.We perform data processing and analysis for light curve and energy spectrum of this blazar.We find PKS 0106+01 have a powerful flare activity from January 2015 to September 2017,and the highest peak flux detected is Flux_{0.1-300Ge V}=(3.09±0.30)×10^-6ph cm^-2s^-1on 10 July2016(MJD 57579.6553,daily average).Simultaneously,the?-ray luminosity is L_?=8.49×10⁴⁸erg s^-1,indicating that PKS 0106+01 is one of the brightest active galactic nuclei detected at high redshift in?-rays.We obtain the shortest variability timescale is 12.5-hour by fitting its one-day binned light curve,and estimate the minimum Doppler factor and the distance of the?-ray emission region from the central engine was?_min?12.06 and r?0.04pc,respectively.It's very close to the central engine.We find Ge V spectral cutoff in the most of?-ray flare periods of PKS 0106+01.In this paper,we consider absorption effect with the EBL model proposed by Finke in 2010 to analyze its??absorption optical depth.It can be concluded that the?-ray spectral cutoff possibly is not due to EBL absorption.The absorption of Ly-?in the broad line region may cause?-ray spectral cutoff.Since the?-ray emission region and the high-energy radiation mechanism have not been constrained,it is not certain whether the cause of the Ge V spectral cutoff is due to the Klein–Nishina effects or the absorption in the broad line region.