论文标题

3C 279在2017-2018耀斑期间的宽带可变性和相关研究

Broadband variability and correlation study of 3C 279 during flare of 2017-2018

论文作者

Prince, Raj

论文摘要

这项工作在2017年11月 - 2017年11月在2017年11月的3C 279耀斑进行了多小波的时间和光谱分析。在X射线和光学/紫外线以及长时间的静态状态下同时观察到三个明亮的伽马射线耀斑。在燃烧时期,在伽马射线和X射线射线中都观察到“较难的当时”趋势。所有耀斑的伽马射线光曲线都在一日的时间内进行了箱,并观察到日标度变化。可变性时间将排放区域的大小和位置限制为2.1 $ \ times $ 10 $^{16} $ cm和4.4 $ \ times $ 10 $^{17} $ cm。分数可变性表明,伽马射线中的源超过100 \%变量,并且降低了较低的能量。使用\ textit {dcf}方法对来自不同波段发射的互相关研究进行了,该方法显示它们之间的相关性很强,没有任何时间滞后。不同波段之间的零时间滞后表明它们的共同空间起源。这是3C 279首次显示伽玛射线与X射线发射与零时间滞后之间存在很强的相关性。采用单个区域排放模型通过使用公开可用的代码gamera对多波长SED进行建模。该研究表明,需要较高的电子射流功率来解释在耀斑状态下的伽马射线通量,这是静态状态所需的十倍。然而,与耀斑状态相比,在静态状态下已经观察到磁场中的喷射功率更多。

A multiwavelength temporal and spectral analysis of flares of 3C 279 during November 2017--July 2018 are presented in this work. Three bright gamma-ray flares were observed simultaneously in X-ray and Optical/UV along with a prolonged quiescent state. A "harder-when-brighter" trend is observed in both gamma-rays and X-rays during the flaring period. The gamma-ray light curve for all the flares are binned in one-day time bins and a day scale variability is observed. Variability time constrains the size and location of the emission region to 2.1$\times$10$^{16}$ cm and 4.4$\times$10$^{17}$ cm, respectively. The fractional variability reveals that the source is more than 100\% variable in gamma-rays and it decreases towards the lower energy. A cross-correlation study of the emission from different wavebands is done using the \textit{DCF} method, which shows a strong correlation between them without any time lags. The zero time lag between different wavebands suggest their co-spatial origin. This is the first time 3C 279 has shown a strong correlation between gamma-rays and X-rays emission with zero time lag. A single zone emission model was adopted to model the multiwavelength SEDs by using the publicly available code GAMERA. The study reveals that a higher jet power in electrons is required to explain the gamma-ray flux during the flaring state, as much as, ten times of that required for the quiescent state. However, more jet power in magnetic field has been observed during the quiescent state compared to the flaring state.

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