Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2010-08-19
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
4 pages, 2 figures, accepted by ApJ
Scientific paper
We investigate the effect of a new triple-alpha reaction rate from Ogata et al. (2009) on helium ignition conditions on accreting neutron stars and on the properties of the subsequent type I X-ray burst. We find that the new rate leads to significantly lower ignition column density for accreting neutron stars at low accretion rates. We compare the results of our ignition models for a pure helium accretor to observations of bursts in ultra-compact X-ray binary (UCXBs), which are believed to have nearly pure helium donors. For mdot > 0.001 mdot_Edd, the new triple-alpha reaction rate from Ogata et al. (2009) predicts a maximum helium ignition column of ~ 3 x 10^9 g cm^{-2}, corresponding to a burst energy of ~ 4 x 10^{40} ergs. For mdot ~ 0.01 mdot_Edd at which intermediate long bursts occur, the predicted burst energies are at least a factor of 10 too low to explain the observed energies of such bursts in UCXBs. This finding adds to the doubts cast on the triple-alpha reaction rate of Ogata et al. (2009) by the low-mass stellar evolution results of Dotter & Paxton (2009).
Ott Christian David
Peng Fang
No associations
LandOfFree
Helium Ignition on Accreting Neutron Stars with a New Triple-alpha Reaction Rate 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 Helium Ignition on Accreting Neutron Stars with a New Triple-alpha Reaction Rate, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Helium Ignition on Accreting Neutron Stars with a New Triple-alpha Reaction Rate will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-80241