Galactic Evolution of D and 3He Including Stellar Production of 3He

Dearborn, David S. P.; Steigman, Gary; Tosi, M.

doi:10.1086/177472

Cited by 76 publications

(60 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…density of 8 M pc À2 (Matteucci & François 1989), X ¼ 0:4 corresponds to an excess infall rate of 0:0006 M kpc À2 yr À1 . This value is below and thus compatible with the previously calculated total infall rates of 0:002 0:004 M kpc À2 yr À1 (see Dearborn et al 1996).…”

Section: Resultssupporting

confidence: 92%

“…The change with time for 3 He is more complex. In the early part of galactic evolution, destruction of 3 He in massive stars will be counteracted by production from D burning, resulting in a relatively flat 3 He evolution curve (Dearborn, Steigman, & Tosi 1996). It is only after several gigayears in the life of a galaxy that 3 He production from incomplete hydrogen burning could become significant when the lowmass stars start to die.…”

Section: Observations and Measurement Resultsmentioning

confidence: 99%

“…This hypothesis, however, does not explain the relatively small difference between the D abundances of the PSC and the LIC. Infall of modestly processed material into the Galactic disk is needed, as has been shown by modeling of the Galactic evolution of D and 3 He (Dearborn et al 1996;Tosi 1998;Prantzos et al 1996).…”

Section: Infall Of External Materials Into the Galactic Diskmentioning

confidence: 99%

See 2 more Smart Citations

Chemical Evolution in Our Galaxy during the Last 5 Gyr

Geiss

Gloeckler

Charbonnel

2002

ApJ

View full text Add to dashboard Cite

A significant fraction of the gas in the Galactic disk comes from quasi-continuous infall of external material that is moderately processed by stellar nucleosynthesis. Based on a comparison of the abundances in the protosolar cloud (PSC) and the Local Interstellar Cloud (LIC), we propose that the infalling matter carries the nucleosynthetic signature of dwarf galaxies. The dwarfs have low metallicity, and secondary products of stellar nucleosynthesis are scarce as compared to primary products. Using a simple model, we show that the differences found in the LIC and PSC compositions can be explained by adding material processed in dwarf galaxies to the material processed in the Galactic disk. Moreover, some previously unexplained composition observations in the Galaxy, such as the apparently anomalously high metallicity of the Sun, or the '' 18 O puzzle '' could be resolved in this way.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Observations and Measurement Resultsmentioning

confidence: 99%

Section: Infall Of External Materials Into the Galactic Diskmentioning

confidence: 99%

See 1 more Smart Citation

Chemical Evolution in Our Galaxy during the Last 5 Gyr

Geiss

Gloeckler

Charbonnel

2002

ApJ

View full text Add to dashboard Cite

show abstract

“…Standard stellar theory for low-mass stars (see, e.g., Iben & Truran 1978) predicts a significant amount of production in these stars. When incorporated into simple models of Galactic chemical evolution, one would expect 3 He abundances in great excess from those observed (Vangioni-Flam, Olive, & Prantzos 1994;Olive et al 1995;Galli et al 1995;Scully et al 1996Scully et al , 1997Dearborn, Steigman, & Tosi 1996). While it is quite possible that additional 3 He destruction mechanisms (Charbonnel 1994(Charbonnel , 1995(Charbonnel , 1996Hogan 1995;Wasserburg, Boothroyd, & Sackmann 1995) can lead to a consistent picture for the evolution of 3 He Galli et al 1997), one must argue that the new process is not operative in all stars in order to avoid a contradiction between a few planetary nebulae showing high 3 He abundances (from 2 to 10 Â 10 À4 : Balser et al 1997; and H ii regions with small 3 He content (about 2 Â 10 À5 ; .…”

Section: Introductionmentioning

confidence: 99%

On the Baryometric Status of³He

Vangioni‐Flam

Olive

Fields

et al. 2003

ApJ

View full text Add to dashboard Cite

Recent observations by Bania et al. measure 3 He versus oxygen in Galactic H ii regions, finding that 3 He/H is within a factor of 2 of the solar abundance for ½O=H e À 0:6. These results are consistent with a flat behavior in this metallicity range, tempting one to deduce from these observations a primordial value for the 3 He abundance, which could join D and 7 Li as an indicator of the cosmic baryon density. However, using the same data, we show that it is not possible to obtain a strong constraint on the baryon density range. This is due to (1) the intrinsically weak sensitivity of the primordial 3 He abundance to the baryon density, (2) the limited range in metallicity of the sample, (3) the intrinsic scatter in the data, and (4) our limited understanding of the chemical and stellar evolution of this isotope. Consequently, the 3 He observations correspond to an extended range of baryon-to-photon ratio, ¼ ð2:2 6:5Þ Â 10 À10 , which diminishes the role of 3 He as a precision baryometer. On the other hand, once the baryon-to-photon ratio is determined by the cosmic microwave background, D/H, or 7 Li/H, the primordial value of 3 He/H can be inferred. Henceforth, new observations of Galactic 3 He can in principle greatly improve our understanding of stellar and/or chemical evolution and reconcile the observations of the H ii regions and those of the planetary nebulae.

show abstract

“…According to standard stellar models, 3 He is most efficiently produced on the main sequence (MS) of 1-2 M stars through the action of the p-p chains. In order not to overproduce 3 He in the course of Galactic evolution, it has become customary to assume that some unknown 3 He-destruction mechanism is at work in more than 90% of low-mass stars (Dearborn et al 1996, Galli et al 1997, Chiappini et al 2002, Romano et al 2003. Hogan (1995) and Charbonnel (1995) have suggested 'extra mixing' during the red giant branch (RGB) phase of low-mass stars as a possible solution (see also Charbonnel & Do Nascimento 1998, Sackmann & Boothroyd 1999.…”

Section: Introductionmentioning

confidence: 99%

Galactic evolution of D, ³He and ⁴He

Romano

2009

Proc. IAU

View full text Add to dashboard Cite

Abstract. The uncertainties which still plague our understanding of the evolution of the light nuclides D, 3 He and 4 He in the Galaxy are described. Measurements of the local abundance of deuterium range over a factor of 3. The observed dispersion can be reconciled with the predictions on deuterium evolution from standard Galactic chemical evolution models, if the true local abundance of deuterium proves to be high, but not too high, and lower observed values are due to depletion onto dust grains. The nearly constancy of the 3 He abundance with both time and position within the Galaxy implies a negligible production of this element in stars, at variance with predictions from standard stellar models which, however, do agree with the (few) measurements of 3 He in planetary nebulae. Thermohaline mixing, inhibited by magnetic fields in a small fraction of low-mass stars, could in principle explain the complexity of the overall scenario. However, complete grids of stellar yields taking this mechanism into account are not available for use in chemical evolution models yet. Much effort has been devoted to unravel the origin of the extreme helium-rich stars which seem to inhabit the most massive Galactic globular clusters. Yet, the issue of 4 He evolution is far from being fully settled even in the disc of the Milky Way.

show abstract

Galactic Evolution of D and 3He Including Stellar Production of 3He

Cited by 76 publications

References 33 publications

Chemical Evolution in Our Galaxy during the Last 5 Gyr

Chemical Evolution in Our Galaxy during the Last 5 Gyr

On the Baryometric Status of³He

Galactic evolution of D, ³He and ⁴He

Contact Info

Product

Resources

About

Galactic Evolution of D and 3He Including Stellar Production of 3He

Cited by 76 publications

References 33 publications

Chemical Evolution in Our Galaxy during the Last 5 Gyr

Chemical Evolution in Our Galaxy during the Last 5 Gyr

On the Baryometric Status of3He

Galactic evolution of D, 3He and 4He

Contact Info

Product

Resources

About

On the Baryometric Status of³He

Galactic evolution of D, ³He and ⁴He