2003/01/31 by Susumu Inoue, Nobuyuki Iwamoto, Manabu Orito +1
Physics and Astronomy · #Astro and Planetary Science #Baryon #Big Bang nucleosynthesis #Gamma-ray burst #Gamma-ray bursts and supernovae #Neutron #Neutron star #Nuclear physics research studies #Nuclear reaction #Nucleosynthesis #Observable #astro-ph #r-process
paper · pdf · doi:10.1086/377298
published as Astrophys.J.595:294-303,2003 · ApJ, in press; 11 pages, 3 figures
arxiv created 2003/06/04 · openalex publication_date 2003/09/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Robust generation of gamma-ray bursts (GRBs) implies the formation of outflows with very low baryon loads and highly relativistic velocities, but more baryon-rich, slower outflows are also likely to occur in most GRB central engine scenarios, either as "circumjet winds" or as "failed GRBs." Here we study the possibility of nucleosynthesis within such baryon-rich outflows by conducting detailed reaction network calculations in the framework of the basic fireball model. It is shown that high baryon load fireballs attaining mildly relativistic velocities can synthesize appreciable quantities of heavy neutron capture elements with masses up to the platinum peak and beyond. Small but interesting amounts of light elements such as deuterium and boron can also be produced. Depending on the neutron excess and baryon load, the combination of high entropy, rapid initial expansion, and gradual expansion at later times can cause the reaction flow to reach the fission regime, and its path can be intermediate between those of the r - and s -processes (" n -process"). The nucleosynthetic signature of these outflows may be observable in the companion stars of black hole binary systems and in the most metal-poor stars, potentially offering an important probe of the inner conditions of the GRB source. Contribution to the solar abundances for some heavy elements may also be possible. The prospects for further developments in various directions are discussed.