SIMBAD references

1998PASP..110....3G - Publ. Astron. Soc. Pac., 110, 3-26 (1998/January-0)

Nucleosynthesis in classical novae and its contribution to the interstellar medium.


Abstract (from CDS):

Classical novae, explosions that result from thermonuclear runaways (TNRs) on the surfaces of white dwarfs (WDs) accreting hydrogen-rich matter in close binary systems, are sporadically injecting material processed by explosive hydrogen burning nucleosynthesis into the interstellar medium (ISM). Although novae probably have processed less than ∼0.3% of the interstellar matter in the Galaxy, both theoretical and observational evidence suggests that they may be important sources of the nuclides ^7Li, ^{15}N, and ^{17}O, as well as the radioactive isotopes ^{22}Na and ^{26}Al. The latter nuclides are astrophysically important in that they may have been involved in the production of the ^{22}Ne (Ne-E) and ^{26}Mg enrichments identified in meteoritic inclusions whose composition is thought to be representative of the chemical and mineral contents of the primitive solar nebula. These inclusions may be partially composed of dust condensed in nova outbursts. We review theoretical expectations for the yields of various isotopes in nova outbursts, and conclude that any of the heavy isotope anomalies attributable to novae are most likely produced by the approximately 25 to 33% of novae that occur in systems containing massive (M_* > 1.2 M_☉) oxygen-neon-magnesium (ONeMg) WDs. We attempt to place quantitative constraints on the degree to which classical novae participate in the production of chemical anomalies, both in the primitive solar system and on a Galactic scale. Diffuse Galactic γ- rayfluxes provide particularly important clues to and constraints on the ^{22}Na and ^{26}Al yields from novae. Ultraviolet (UV), optical, and infrared (IR) emission line spectra of classical novae reveal the abundances of some of the gas phase elements present in the ejecta; recent results are reviewed. We describe how IR observations of novae reveal dust formation and gas-phase line emission, and how they distinguish the temporal development of nova explosions on carbon-oxygen (CO) WDs (CO novae) from those on ONeMg WDs (ONeMg or "neon" novae). Recent studies show that the ejecta in some novae can be strongly cooled by near- and mid-IR forbidden line radiation from highly ionized (``coronal") atomic states. We compare the abundances deduced from recent UV, Optical, and IR observations with theoretical predictions, and suggest future studies of IR coronal emission lines may provide additional key information. Novae produce only about 0.1 % of the Galactic ``stardust'' (dust condensed in stellar outflows), but IR observations show that it may be some of the more interesting dust. Novae appear capable of producing astrophysical dust of virtually every known chemical and mineral composition. We summarize recent IR observations of the dust production scenario in novae, and argue that Neon Novae may lead to the formation of dust grains that carry the Ne-E and ^{26}Mg anomalies. (c)Astronomical Society of the Pacific

Abstract Copyright:

Journal keyword(s): Invited Review Article

Simbad objects: 30

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:1998PASP..110....3G and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact