A lower occurrence rate of bright X-ray flares in SN-GRBs than z < 1 GRBs: evidence of energy partitions?. Issue 3 (18th May 2018)

• Record Type: Journal Article
• Authors: Mu, Hui-Jun; Gu, Wei-Min; Mao, Jirong; Liu, Tong; Hou, Shu-Jin; Lin, Da-Bin; Wang, Junfeng; Fang, Taotao; Liang, En-Wei
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 478:Issue 3(2018)
• Page Start: 3605
• Page End: 3613
• Publication Date: 2018-05-18
• Subjects: gamma-ray burst: general -- supernovae: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty1288
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The occurrence rates of bright X-ray flares in z < 1 gamma-ray bursts (GRBs) with or without observed supernovae (SNe) association were compared. Our Sample I: the z < 1 long GRBs (LGRBs) with SNe association (SN-GRBs) and with early Swift /X-Ray Telescope (XRT) observations, consists of 18 GRBs, among which only two GRBs have bright X-ray flares. Our Sample II: for comparison, all the z < 1 LGRBs without observed SNe association and with early Swift /XRT observations, consists of 45 GRBs, among which 16 GRBs present bright X-ray flares. Thus, the study indicates a lower occurrence rate of bright X-ray flares in Sample I (11.1 per cent) than in Sample II (35.6 per cent). In addition, if dim X-ray fluctuations are included as flares, then 16.7 per cent of Sample I and 55.6 per cent of Sample II are found to have flares, again showing the discrepancy between these two samples. We examined the physical origin of these bright X-ray flares and found that most of them are probably related to the central engine reactivity. To understand the discrepancy, we propose that such a lower occurrence rate of flares in the SN-GRB sample may hint at an energy partition among the GRB, SNe, and X-ray flares under a saturated energy budget of massive star explosion.