论文标题
调查2015 - 2019年3C273中伽马射线活动与相对论喷气的联系
Investigating the connection between gamma-ray activity and relativistic jet in 3C273 during 2015-2019
论文作者
论文摘要
由于其在整个电磁频谱及其无线电飞机活动中的强大辐射，Blazar 3C273提供了研究活跃银河系核$γ$ ray射分物理学的机会。自2009年历史上发生强烈的爆发以来，3C273在伽马射线频段中表现出相对较弱的发射。但是，最近的费米大型区域望远镜观测表明，2015 - 2019年期间的活动升高。我们旨在将伽马射线爆发的起源限制在3C273上，并研究它们与Parsec尺度喷气机的联系。我们生成具有多个嵌入间隔的费米 - 拉特伽马射线光曲线，并研究伽马射线发射的光谱特性。使用3毫米ALMA光曲线，我们研究无线电和伽马射线发射之间的相关性。研究了3C273的PARSEC大规模喷射中的相关活动，并通过7毫米VLBA观测值在近距离观察到著名的伽马射线爆发。我们在2016年发现了两次著名的伽马射线爆发（MJD 57382）和2017年（MJD 57883），并伴有MM波长耀斑的活动。伽马射线光子指数时间序列序列显示了伽玛射线爆发周围的驼峰状功能较弱。每月的伽马射线通量折线图指示从柔和的汉堡到较硬的汉堡，价格为$ 1.03 \ times10^{ - 7} \ rm \，ph \，ph \，cm^，cm^{ - 2} { - 2} \，s^{ - 1} $。发现伽马射线和MM波长发射之间存在显着相关性，无线电滞后约105-112天。 43-GHz喷射图像揭示了射流上游区域中已知的固定特征（即核心，S1和S2）。我们发现指示了在两个伽马射线爆发时代周围固定成分之间的繁殖干扰和两极分化的结。
Due to its powerful radiation over the entire electromagnetic spectrum and its radio jet activity, the blazar 3C273 offers the opportunity to study the physics of $γ$-ray emission from active galactic nuclei. Since a historically strong outburst in 2009, 3C273 showed relatively weak emission in the gamma-ray band over multiple years. However, recent Fermi-Large Area Telescope observations indicate elevated activity during 2015-2019. We aim at constraining the origin of the gamma-ray outbursts towards 3C273 and investigate their connection to the parsec-scale jet. We generate Fermi-LAT gamma-ray light curves with multiple binning intervals and study the spectral properties of the gamma-ray emission. Using a 3-mm ALMA light curve, we study the correlation between radio and gamma-ray emission. Relevant activity in the parsec-scale jet of 3C273 is investigated with 7-mm VLBA observations obtained close in time to notable gamma-ray outbursts. We find two prominent gamma-ray outbursts in 2016 (MJD 57382) and 2017 (MJD 57883) accompanied by mm-wavelength flaring activity. The gamma-ray photon index time series show a weak hump-like feature around the gamma-ray outbursts. The monthly gamma-ray flux-index plot indicates a transition from softer-when-brighter to harder-when-brighter at $1.03\times10^{-7}\rm\,ph\,cm^{-2}\,s^{-1}$. A significant correlation between the gamma-ray and mm-wavelength emission is found, with the radio lagging the gamma-rays by about 105-112 days. The 43-GHz jet images reveal the known stationary features (i.e., the core, S1, and S2) in a region upstream of the jet. We find indication for a propagating disturbance and a polarized knot between the stationary components around the times of both gamma-ray outbursts.
