Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-06-16
Astronomy and Astrophysics
Astrophysics
14 pages and 3 Postscript figures, Accepted for publication on ApJ Letters
Scientific paper
10.1086/312166
Hydrogen-rich matter has been added to a CO white dwarf of initial mass 0.516 \msun at the rates $10^{-8}$ and $2\times 10^{-8}$ \msun \yrm1, and results are compared with those for a white dwarf of the same initial mass which accretes pure helium at the same rates. For the chosen accretion rates, hydrogen burns in a series of recurrent mild flashes and the ashes of hydrogen burning build up a helium layer at the base of which a He flash eventually occurs. In previous studies involving accretion at higher rates and including initially more massive WDs, the diffusion of energy inward from the H shell-flashing region contributes to the increase in the temperature at the base of the helium layer, and the mass of the helium layer when the He flash begins is significantly smaller than in a comparison model accreting pure helium; the He shell flash is not strong enough to develop into a supernova explosion. In contrast, for the conditions adopted here, the temperature at the base of the He layer becomes gradually independent of the deposition of energy by H shell flashes, and the mass of the He layer when the He flash occurs is a function only of the accretion rate, independent of the hydrogen content of the accreted matter. When the He flash takes place, due to the high degeneracy at the base of the He layer, temperatures in the flashing zone will rise without a corresponding increase in pressure, nuclear burning will continue until nuclear statistical equilibrium is achieved; the model will become a supernova, but not of the classical type Ia variety.
Icko Iben Jr.
Cassisi Santi
Piersanti Luciano
Tornambe' Amedeo
No associations
LandOfFree
On the very long term evolutionary behavior of hydrogen-accreting Low-Mass CO white dwarfs 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 On the very long term evolutionary behavior of hydrogen-accreting Low-Mass CO white dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the very long term evolutionary behavior of hydrogen-accreting Low-Mass CO white dwarfs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-108987