Nucleosynthesis in ONeMg Novae: Models versus Observations to Constrain the Masses of ONeMg White Dwarfs and Their Envelopes

Citations Over TimeTop 10% of 1999 papers

Abstract

Nucleosynthesis in ONeMg novae has been investigated with the wide ranges of three parameters, i.e., the white dwarf mass, the envelope mass at ignition, and the initial composition. A quasi-analytic one-zone approach is used with an up-to-date nuclear reaction network. The nucleosynthesis results show correlation with the peak temperatures or the cooling timescales during outbursts. Among the combinations of white dwarf and envelope masses which give the same peak temperature, the explosion is more violent for a lower white dwarf mass owing to its smaller gravitational potential. Comparison of the nucleosynthesis results with observations implies that at least two-third of the white dwarf masses for the observed ONeMg novae are $\simeq 1.1 M_\odot$, which are significantly lower than estimated by previous hydrodynamic studies but consistent with the observations of V1974 Cyg. Moreover, the envelope masses derived from the comparison are $\gtrsim 10^{-4} M_\odot$, which are in good agreement with the ejecta masses estimated from observations but significantly higher than in previous hydrodynamic studies. With such a low mass white dwarf and a high mass envelope, the nova can produce interesting amounts of $\gamma$-ray emitters $^7$Be, $^{22}$Na, and $^{26}$Al. We suggest that V1974 Cyg has produced $^{22}$Na as high as the upper limit derived from the COMPTEL survey. In addition, a non-negligible part of the Galactic $^{26}$Al may originate from ONeMg novae, if not the major contributors. Both the future INTEGRAL survey for these $\gamma$-ray emitters and abundance estimates derived from ultraviolet, optical, and near infrared spectroscopies will impose a severe constraint on the current nova models.

Related Papers

• → Post-AGB Stars as Tracers of AGB Nucleosynthesis: An Update(2022)8 cited
• → Nucleosynthesis in AGB Stars(2006)1 cited
• → News from Low Mass Star Nucleosynthesis and Mixing(2010)
• → The effect of the recent17O(p,α)14N and18O(p,α)15N fusion cross section measurements in the nucleosynthesis of AGB stars(2015)
• → Neutron-Capture Nucleosynthesis and the Chemical Evolution of Globular Clusters(2015)