2013/01/11 by Akihiro Suzuki, Toshikazu Shigeyama · 19 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Circumstellar disk #Circumstellar envelope #Ejecta #Gamma-ray bursts and supernovae #Jet (fluid) #Observable #Pulsars and Gravitational Waves Research #Thermal #Thermal emission #astro-ph.HE
paper · pdf · doi:10.1088/2041-8205/764/1/l12
published in The Astrophysical Journal Letters 764(1), L12 (IOP Publishing) · 6 pages, 5 figures, accepted for publication in ApJL
arxiv created 2013/01/11 · openalex publication_date 2013/01/29 · arxiv updated 2015/06/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We performed a series of hydrodynamical calculations of an ultrarelativistic jet propagating through a massive star and the circumstellar matter (CSM) to investigate the interaction between the ejecta and the CSM. We succeed in distinguishing two qualitatively different cases in which the ejecta are shocked and adiabatically cool. To examine whether the cocoon expanding at subrelativistic speeds emits any observable signal, we calculate the expected photospheric emission from the cocoon. It is found that the emission can explain early thermal X-ray emission recently found in some long gamma-ray bursts (GRBs). The result implies that the difference of the circumstellar environment of long GRBs can be probed by observing their early thermal X-ray emission.