Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-05-30
Astrophys.J.666:1140-1151,2007
Astronomy and Astrophysics
Astrophysics
33 pages, 13 figures, accepted by ApJ
Scientific paper
10.1086/520080
The existence of various anomalous stars, such as the first stars in the universe or stars produced by stellar mergers, has been recently proposed. Some of these stars will result in black hole formation. In this study, we investigate iron core collapse and black hole formation systematically for the iron-core mass range of 3 - 30Msun, which has not been studied well so far. Models used here are mostly isentropic iron cores that may be produced in merged stars in the present universe but we also employ a model that is meant for a Population III star and is obtained by evolutionary calculation. We solve numerically the general relativistic hydrodynamics and neutrino transfer equations simultaneously, treating neutrino reactions in detail under spherical symmetry. As a result, we find that massive iron cores with ~10Msun unexpectedly produce a bounce owing to the thermal pressure of nucleons before black hole formation. The features of neutrino signals emitted from such massive iron cores differ in time evolution and spectrum from those of ordinary supernovae. Firstly, the neutronization burst is less remarkable or disappears completely for more massive models because the density is lower at the bounce. Secondly, the spectra of neutrinos, except the electron type, are softer owing to the electron-positron pair creation before the bounce. We also study the effects of the initial density profile, finding that the larger the initial density gradient is, the more steeply the neutronization burst declines. Further more, we suggest a way to probe into the black hole progenitors from the neutrino emission and estimate the event number for the currently operating neutrino detectors.
Nakazato Ken'ichiro
Sumiyoshi Kohsuke
Yamada Shoichi
No associations
LandOfFree
Numerical Study on Stellar Core Collapse and Neutrino Emission: Probe into the Spherically Symmetric Black Hole Progenitors with 3 - 30Msun Iron Cores 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 Numerical Study on Stellar Core Collapse and Neutrino Emission: Probe into the Spherically Symmetric Black Hole Progenitors with 3 - 30Msun Iron Cores, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Numerical Study on Stellar Core Collapse and Neutrino Emission: Probe into the Spherically Symmetric Black Hole Progenitors with 3 - 30Msun Iron Cores will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-357164