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arXiv 2201.01167astro-ph.HE
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用时间分辨光谱和偏振研究探讨GRB 190530 A的发射机制:同步辐射起源?

Probing into emission mechanisms of GRB 190530A using time-resolved spectra and polarization studies: Synchrotron Origin?

Rahul Gupta, S. Gupta, T. Chattopadhyay, V. Lipunov, A. J. Castro-Tirado, D. Bhattacharya, S. B. Pandey, S. R. Oates, Amit Kumar, Y. -D. Hu, A. F. Valeev, P. Yu… 展开作者

Rahul Gupta, S. Gupta, T. Chattopadhyay, V. Lipunov, A. J. Castro-Tirado, D. Bhattacharya, S. B. Pandey, S. R. Oates, Amit Kumar, Y. -D. Hu, A. F. Valeev, P. Yu. Minaev, H. Kumar, J. Vinko, Dimple, V. Sharma, A. Aryan, A. Castellón, A. Gabovich, A. Moskvitin, A. Ordasi, A. Pál, A. Pozanenko, B. -B. Zhang, B. Kumar, D. Svinkin, D. Saraogi, D. Vlasenko, E. Fernández-García, E. Gorbovskoy, G. C. Anupama, K. Misra, K. Sárneczky, L. Kriskovics, M. Á. Castro-Tirado, M. D. Caballero-García, N. Tiurina, P. Balanutsa, R. R. Lopez, R. Sánchez-Ramírez, R. Szakáts, S. Belkin, S. Guziy, S. Iyyani, S. N. Tiwari, Santosh V. Vadawale, T. Sun, V. Bhalerao, V. Kornilov, V. V. Sokolov

摘要:

由\fermi上的GBM和LAT探测到的多脉冲GRB 190530 A是迄今为止探测到的第六个最流畅的GBM爆发。本文介绍了使用\AstroSat和\fermi观测到的瞬发辐射的时序、光谱和偏振分析,以深入了解瞬发辐射机制。时间积分谱显示了由于峰值能量和第二个较低的能量断裂而导致的两个断裂的确凿证据。由\AstroSat上的碲锌镉成像仪(CZTI)进行的时间积分(55.43 $\pm$ 21.30 \%)以及时间分辨偏振测量显示出高度偏振的暗示。高偏振度的暗示和低能量光谱指数($α_{\rm pt}$)的值的存在不超过同步极限的前两个脉冲,支持同步起源在一个有序的磁场。然而,在第三个脉冲,$α_{\rm pt}$超过同步线的死亡在几个箱子,和热签名以及同步组件中的时间分辨光谱观察。此外,我们还报道了利用MASTER(P $<$ 1.3)和10.4 m GTC望远镜获得的约束余辉偏振的最早光学观测结果($z$ = 0.9386)。宽带余辉可以用前向激波模型来描述,该模型适用于具有宽喷流张角的类ISM介质。我们确定环爆密度为7.41,动能为7.24,辐射能量为$E_{\rm K} \sim$ 6.05 $\times 10^{54}$ erg.

英文摘要:

Multi-pulsed GRB 190530A, detected by the GBM and LAT onboard \fermi, is the sixth most fluent GBM burst detected so far. This paper presents the timing, spectral, and polarimetric analysis of the prompt emission observed using \AstroSat and \fermi to provide insight into the prompt emission radiation mechanisms. The time-integrated spectrum shows conclusive proof of two breaks due to peak energy and a second lower energy break. Time-integrated (55.43 $\pm$ 21.30 \%) as well as time-resolved polarization measurements, made by the Cadmium Zinc Telluride Imager (CZTI) onboard \AstroSat, show a hint of high degree of polarization. The presence of a hint of high degree of polarization and the values of low energy spectral index ($α_{\rm pt}$) do not run over the synchrotron limit for the first two pulses, supporting the synchrotron origin in an ordered magnetic field. However, during the third pulse, $α_{\rm pt}$ exceeds the synchrotron line of death in few bins, and a thermal signature along with the synchrotron component in the time-resolved spectra is observed. Furthermore, we also report the earliest optical observations constraining afterglow polarization using the MASTER (P $<$ 1.3 \%) and the redshift measurement ($z$= 0.9386) obtained with the 10.4m GTC telescopes. The broadband afterglow can be described with a forward shock model for an ISM-like medium with a wide jet opening angle. We determine a circumburst density of $n_{0} \sim$ 7.41, kinetic energy $E_{\rm K} \sim$ 7.24 $\times 10^{54}$ erg, and radiated $γ$-ray energy $E_{\rm γ, iso} \sim$ 6.05 $\times 10^{54}$ erg, respectively.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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