Sunday, February 17, 2013

Nucleosynthesis in the gamma-ray burst accretion disks and associated outflows. (arXiv:1302.3067v1 [astro-ph.HE])

Nucleosynthesis in the gamma-ray burst accretion disks and associated outflows. (arXiv:1302.3067v1 [astro-ph.HE]):
We investigate nucleosynthesis inside the gamma-ray burst (GRB) accretion
disks formed by the Type II collapsars and outflows launched from these disks.
We deal with accretion disks having relatively low accretion rates: 0.001 M_sun
s^{-1} <~ Mdot <~ 0.01 M_sun s^{-1} and hence they are predominantly advection
dominated. We report the synthesis of several unusual nuclei like 31P, 39K,
43Sc, 35Cl and various isotopes of titanium, vanadium, chromium, manganese and
copper in the disk. We also confirm that isotopes of iron, cobalt, nickel,
argon, calcium, sulphur and silicon get synthesized in the disk, as shown by
previous authors. Much of these heavy elements thus synthesized are ejected
from the disk and survive in the outflows. Indeed, emission lines of many of
these heavy elements have been observed in the X-ray afterglows of several
GRBs.

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