Astronomy and Astrophysics – Astrophysics
Scientific paper
Apr 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002aps..apr.y2001m&link_type=abstract
American Physical Society, April Meeting, Jointly Sponsored with the High Energy Astrophysics Division (HEAD) of the American As
Astronomy and Astrophysics
Astrophysics
Scientific paper
A collapsar is a massive rotating star (M_ms > 25 M_sun) whose core collapses to form a black hole. In a rapidly rotating star, the accretion of the rest of the star into the newly-formed black hole produces an energetic long-duration gamma-ray burst (GRB) accompanied by a Type Ib/c supernova. An accretion disk forms as the outer layers of the star fall into the black hole (3 < M_hole/M_sun < 10) at its center. Rapid accretion of stellar matter into the hole at rates of up to 0.1 M_sun s-1 releases large amounts of energy (approx. 10^51 erg s-1) some of which is deposited in the low density rotation axis of the star. The heated gas at the pole expands in a jet-like fireball which penetrates the surface of the star, escapes to large distances, and makes the observed gamma-ray photons and lower energy afterglow at large distances (> 1000 stellar radii). Since collapsars naturally form jetted explosions beamed to approximately 1% of the sky, the energetic requirement is typically hundreds of times less than the observed ``isotropic equivalent energy.'' Supernova-like energies of 10^51-10^52 ergs, as calculated in models to be presented, are therefore sufficient to explain GRBs with a range of isotropic equivalent energies up to, and exceeding, 10^54 ergs depending on the beaming angle. Outflowing winds blown from the accretion disk can produce stellar explosions independant of any GRB-producing jet which may also occur. These wind-driven explosions may occur in stellar explosions which do not make a GRB and constitute a new class of supernova explosion. A key feature of the collapsar winds is that they are capable of producing radioactive elements (e.g., ^56Ni) necessary to power a long-duration supernova light curve. The observational signatures of collapsars are diverse and depend on the beaming of the explosion, the amount of radioactive ^56Ni produced and mixed into the stellar envelope, the angular momentum of the progenitor star and its radius at core collapse. Recent observational evidence, both the close association of well-localized GRBs with star-forming regions and possible direct links between GRBs and supernovae, supports the collapsar model.
No associations
LandOfFree
Gamma Ray Burst Progenitors: the collapsar model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gamma Ray Burst Progenitors: the collapsar model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gamma Ray Burst Progenitors: the collapsar model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1535087