3He in Planetary Nebulae: A Challenge to Stellar Evolution Models

Abstract

The discrepancy between the observed abundances of 3He in the ISM and those predicted by stellar and galactic chemical evolution remains largely unexplained. In this paper, we attempt to shed some light on this unsolved problem by presenting a quantitative comparison of the 3He abundances recently measured in six planetary nebulae (PNe) with the corresponding predictions of stellar evolution theory. The determination of the mass of the PNe progenitors allows us to dismiss, to a good degree of confidence, the hypothesis that the abundance of 3He in the envelope of all low-mass stars is strongly reduced with respect to the standard theoretical values by some mixing mechanism acting in the latest phases of stellar evolution. The abundance versus mass correlation, allowance made for the limitation of the sample, is in fact found to be fully consistent with the classical prediction of stellar evolution. We examine the implications of this result on the galactic evolution of 3He with the help of a series of models with standard and non-standard nucleosynthesis prescriptions. The results are found to be consistent with the observed galactic abundances only if the vast majority of low-mass stars follows non-standard prescriptions. This implies that either the sample of PNe nebulae under exam is highly biased, or the solution to the 3He problem lies elsewhere.

13 pages, LaTeX, 4 Figures. To be published in The Astrophysical Journal

References in corpus (2)

• Galactic Evolution Of D And 3He Including Stellar Production Of 3He
• On the Evoution of the Light Elements I. D, He-3, and He-4

Cited by in corpus (26)

• Big Bang Nucleosynthesis: 2015
• Primordial Nucleosynthesis: Theory and Observations
• Nova nucleosynthesis and Galactic evolution of the CNO isotopes
• Light element evolution resulting from WMAP data
• Evolution of Deuterium, 3He and 4He in the Galaxy
• On the baryometric status of He3
• Inhibition of thermohaline mixing by a magnetic field in Ap star descendants: Implications for the Galactic evolution of 3He
• Thermohaline instability and rotation-induced mixing II- Yields of 3He for low- and intermediate-mass stars
• Inhomogeneous Big-Bang Nucleosynthesis in Light of Recent Observations
• CO Isotopes in Planetary Nebulae
• Effects of thermohaline instability and rotation-induced mixing on the evolution of light elements in the Galaxy : D, 3He and 4He
• A Stochastic Approach to Chemical Evolution
• Search for 7Be in the outburst of four recent novae
• Spatially resolved physical and chemical properties of the planetary nebula NGC 3242
• Green Bank Telescope Observations of 3He+: HII Regions
• Origin and evolution of the light nuclides
• The 12C/13C ratio in the Planetary Nebula NGC3242 from Hubble Space Telescope STIS observations
• First Detection of ${}^3$He${}^{+}$ in the Planetary Nebula IC418
• Green Bank Telescope Observations of ${}^3\mathbf{H}{\mathbf{e}}^{+}$: Planetary Nebulae
• Big Bang Nucleosynthesis
• Do All Low-Mass Stars Undergo Extra Mixing Processes?
• Big Bang Nucleosynthesis
• 3He: Does the problem persists?
• Measurements of the 12C/13C ratio in Planetary Nebulae and implications for stellar evolution
• Galactic evolution of D, 3He and 4He
• ${}^3$He Abundances in Planetary Nebulae