Peculiar Prompt Emission and Afterglow in the HESS-detected GRB 190829A

被引：37

作者：

Chand, Vikas ^{[1
,2
]}

Banerjee, Ankush

Gupta, Rahul ^{[3
,4
]}

Dimple ^{[3
,4
]}

Pal, Partha Sarathi ^{[5
]}

Joshi, Jagdish C. ^{[1
,2
]}

Zhang, Bin-Bin ^{[1
,2
,6
]}

Basak, R. ^{[7
,8
]}

Tam, P. H. T. ^{[5
]}

Sharma, Vidushi ^{[9
]}

Pandey, S. B. ^{[3
]}

Kumar, Amit ^{[3
,10
]}

Yang, Yi-Si ^{[1
,2
]}

机构：

[1] Nanjing Univ, Sch Astron & Space Sci, Nanjing 210093, Peoples R China

[2] Nanjing Univ, Minist Educ, Key Lab Modern Astron & Astrophys, Nanjing, Peoples R China

[3] Aryabhatta Res Inst Observat Sci ARIES, Naini Tal 263002, India

[4] Deen Dayal Upadhyaya Gorakhpur Univ, Dept Phys, Gorakhpur 273009, Uttar Pradesh, India

[5] Sun Yat Sen Univ, Sch Phys & Astron, Guangzhou 510275, Peoples R China

[6] Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA

[7] INAF OAS Bologna, Via P Gobetti 101, I-41129 Bologna, Italy

[8] Univ Ferrara, Dept Phys & Earth Sci, Block C,Via Saragat 1, I-41122 Ferrara, Italy

[9] Inter Univ Ctr Astron & Astrophys, Pune, Maharashtra, India

[10] Pandit Ravishankar Shukla Univ, Sch Studies Phys & Astrophys, Chattisgarh 492010, India

来源：

ASTROPHYSICAL JOURNAL | 2020年 / 898卷 / 01期

基金：

欧盟地平线“2020”; 中国国家自然科学基金;

关键词：

Gamma-ray bursts; Burst astrophysics; High energy astrophysics; GAMMA-RAY BURSTS; COMPLETE SAMPLE; LONG; FLARES; ENGINE; ENERGETICS; COMPONENT; DURATION; ORIGIN; JET;

D O I：

10.3847/1538-4357/ab9606

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the results of a detailed investigation of the prompt and afterglow emission in the High Energy Stereoscopic System (H.E.S.S.)-detected GRB 190829A. Swift and Fermi observations of the prompt phase of this gamma-ray burst (GRB) reveal two isolated subbursts or episodes, separated by a quiescent phase. The energetic and the spectral properties of the first episode are in stark contrast to the second. The first episode, which has a higher spectral peak similar to 120 keV and a low isotropic energy similar to 10(50)erg is an outlier to the Amati correlation and marginally satisfies the Yonetoku correlation. However, the energetically dominant second episode has lower peak energy and is consistent with the above correlations. We compared this GRB to other low-luminosity GRBs (LLGRBs). Prompt emission of LLGRBs also indicates a relativistic shock breakout origin of the radiation. For GRB 190829A, some of the properties of a shock breakout origin are satisfied. However, the absence of an accompanying thermal component and energy above the shock breakout critical limit precludes a shock breakout origin. In the afterglow, an unusual long-lasting late-time flare of duration similar to 10(4)s is observed. We also analyzed the late-time Fermi Large Area Telescope (LAT) emission that encapsulates the H.E.S.S. detection. Some of the LAT photons are likely to be associated with the source. All of the above observational facts suggest GRB 190829A is a peculiar low-luminosity GRB that is not powered by a shock breakout, and has an unusual rebrightening due to patchy emission or a refreshed shock during the afterglow. Furthermore, our results show that teraelectronvolt-energy photons seem common in both high-luminosity GRBs and LLGRBs.

引用

页数：13