Related papers: Prospects for obtaining an r-process from Gamma Ra…
We study the effects of the outer boundary conditions in neutrino-driven winds on the r-process nucleosynthesis. We perform numerical simulations of hydrodynamics of neutrino-driven winds and nuclear reaction network calculations of the…
Rapid, hyper-Eddington accretion is likely to power the central engines of gamma-ray bursts (GRBs). In the extreme conditions of densities and temperatures the accreting torus is cooled by neutrino emission rather than by radiation. Another…
We consider the long term evolution of debris following the tidal disruption of compact stars in the context of short gamma ray bursts (SGRBs). The initial encounter impulsively creates a hot, dense, neutrino-cooled disk capable of powering…
Several gamma ray bursts have recently been associated with a kilonova emission. We study the mechanisms which could account for this effect, by means of radioactive decay of elements synthesized in accretion disk wind. We model the…
The merger of binary neutron stars, or of a neutron star and a stellar-mass black hole, can result in the formation of a massive rotating torus around a spinning black hole. In addition to providing collimating media for gamma-ray burst…
For accretion rates Mdot~0.1 Msun/s to a few solar mass black hole the inner part of the disk is expected to make a transition from advection dominance to neutrino cooling. This transition is characterized by sharp changes of the disk…
We investigate nuclear reactions and feedback in hyperaccreting neutron star environments, considering accretion rates in the range 0.3 - $3\times10^4$ $M_\odot$ yr$^{-1}$, typical of short-period compact object binaries in common…
We present calculations of r-process nucleosynthesis in neutrino-driven winds from the nascent neutron stars of core-collapse supernovae. A full dynamical reaction network for both the alpha-rich freezeout and the subsequent r-process is…
We examine the prospects for producing Nickel-56 from black hole accretion disks, by examining a range of steady state disk models. We focus on relatively slowly accreting disks in the range of 0.05 - 1 solar masses per second, as are…
We investigate nucleosynthesis inside the gamma-ray burst (GRB) accretion disks formed by the Type II collapsars. In these collapsars, the core collapse of massive stars first leads to the formation of a proto-neutron star and a mild…
The ultrarelativistic jets responsible for prompt and afterglow emission in gamma ray bursts are presumably driven by a central engine that consists of a dense accretion disk around a spinning black hole. We consider such engine, composed…
The neutrino-cooled accretion disk, which was proposed to work as the central engine of gamma-ray bursts, encounters difficulty in interpreting the X-ray flares after the prompt gamma-ray emission. In this paper, the magnetic coupling…
We calculate the structure of accretion disk around a spinning black hole for accretion rates 0.01 - 10 M_sun/s. The model is fully relativistic and treats accurately the disk microphysics including neutrino emissivity, opacity, electron…
The astrophysical origin of elements synthesized through the rapid neutron capture process ($r-$process) is a long standing mystery. The hot and dense environments of core-collapse supernovae have been suggested as potential $r-$process…
The specific mechanism and astrophysical site for the production of half of the elements heavier than iron via rapid neutron capture (r-process) remains to be found. In order to reproduce the abundances of the solar system and of the old…
We discuss various neutrino-nucleus interactions in connection with the supernova r-process nucleosynthesis, which possibly occurs in the neutrino-driven wind of a young neutron star. These interactions include absorptions of electron…
It is often considered that a massive torus with solar mass or so surrounding a stellar-mass black hole may be a central engine of a gamma-ray burst. We study the properties of such massive accretion tori (or disks) based on the $\alpha$…
We consider $r$-process nucleosynthesis in outflows from black hole accretion discs formed in double neutron star and neutron star -- black hole mergers. These outflows, powered by angular momentum transport processes and nuclear…
The r-process constitutes one of the major challenges in nuclear astrophysics. Its astrophysical site has not yet been identified but there is observational evidence suggesting that at least two possible sites should contribute to the solar…
Study of nucleosynthesis in accretion disks around black holes was initiated by Chakrabarti et al. (1987). In the present work we do the similar analysis using the state-of-the-art disk model, namely, Advective Accretion Disks. During the…