Abstract
We report on the results of new calculations of thermonuclear runaways on 1.25 M⊙ oxygen, neon, and magnesium white dwarfs, using our one-dimensional, fully implicit, hydrodynamic stellar evolution code that includes a large nuclear reaction network. We have updated the nuclear reaction network by including both new and improved experimental and theoretical determinations of the nuclear reaction rates. We have also incorporated the carbon-rich OPAL opacity tables. Our results show that the changes in the reaction rates and opacities that we have introduced produce important changes with respect to our previous studies. For example, a smaller amount of 26Al is produced, while the abundances of 31P and 32S increase by factors of more than 2. This change is attributed to the increased proton-capture reaction rates for some of the intermediate-mass nuclei near 26Al and beyond, such that nuclear fusion to higher mass nuclei is enhanced. We also find that our predicted values for the amount of mass ejected in the outburst are at least a factor of 10 less than observed. The low values for the amount of ejected mass is a consequence of the fact that the OPAL opacities are larger than those we previously used, which results in more heat being trapped in the nuclear-burning regions and, therefore, less mass being accreted onto the white dwarf.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 485-495 |
| Number of pages | 11 |
| Journal | Astrophysical Journal, Supplement Series |
| Volume | 127 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 2000 |
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Keywords
- Hydrodynamics
- Novae, cataclysmic variables
- Nuclear reactions, nucleosynthesis, abundances
- White dwarf
ASJC Scopus subject areas
- Space and Planetary Science
Cite this
The effects of new nuclear reaction rates and opacities on hydrodynamic simulations of the nova outburst. / Starrfield, Sumner; Sparks, W. M.; Truran, J. W.; Wiescher, M. C.
In: Astrophysical Journal, Supplement Series, Vol. 127, No. 2, 04.2000, p. 485-495.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The effects of new nuclear reaction rates and opacities on hydrodynamic simulations of the nova outburst
AU - Starrfield, Sumner
AU - Sparks, W. M.
AU - Truran, J. W.
AU - Wiescher, M. C.
PY - 2000/4
Y1 - 2000/4
N2 - We report on the results of new calculations of thermonuclear runaways on 1.25 M⊙ oxygen, neon, and magnesium white dwarfs, using our one-dimensional, fully implicit, hydrodynamic stellar evolution code that includes a large nuclear reaction network. We have updated the nuclear reaction network by including both new and improved experimental and theoretical determinations of the nuclear reaction rates. We have also incorporated the carbon-rich OPAL opacity tables. Our results show that the changes in the reaction rates and opacities that we have introduced produce important changes with respect to our previous studies. For example, a smaller amount of 26Al is produced, while the abundances of 31P and 32S increase by factors of more than 2. This change is attributed to the increased proton-capture reaction rates for some of the intermediate-mass nuclei near 26Al and beyond, such that nuclear fusion to higher mass nuclei is enhanced. We also find that our predicted values for the amount of mass ejected in the outburst are at least a factor of 10 less than observed. The low values for the amount of ejected mass is a consequence of the fact that the OPAL opacities are larger than those we previously used, which results in more heat being trapped in the nuclear-burning regions and, therefore, less mass being accreted onto the white dwarf.
AB - We report on the results of new calculations of thermonuclear runaways on 1.25 M⊙ oxygen, neon, and magnesium white dwarfs, using our one-dimensional, fully implicit, hydrodynamic stellar evolution code that includes a large nuclear reaction network. We have updated the nuclear reaction network by including both new and improved experimental and theoretical determinations of the nuclear reaction rates. We have also incorporated the carbon-rich OPAL opacity tables. Our results show that the changes in the reaction rates and opacities that we have introduced produce important changes with respect to our previous studies. For example, a smaller amount of 26Al is produced, while the abundances of 31P and 32S increase by factors of more than 2. This change is attributed to the increased proton-capture reaction rates for some of the intermediate-mass nuclei near 26Al and beyond, such that nuclear fusion to higher mass nuclei is enhanced. We also find that our predicted values for the amount of mass ejected in the outburst are at least a factor of 10 less than observed. The low values for the amount of ejected mass is a consequence of the fact that the OPAL opacities are larger than those we previously used, which results in more heat being trapped in the nuclear-burning regions and, therefore, less mass being accreted onto the white dwarf.
KW - Hydrodynamics
KW - Novae, cataclysmic variables
KW - Nuclear reactions, nucleosynthesis, abundances
KW - White dwarf
UR - http://www.scopus.com/inward/record.url?scp=0001056027&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0001056027&partnerID=8YFLogxK
U2 - 10.1086/313336
DO - 10.1086/313336
M3 - Article
AN - SCOPUS:0001056027
VL - 127
SP - 485
EP - 495
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
SN - 0067-0049
IS - 2
ER -