Low and intermediate mass star yields

Gavilán, M.; Mollá, M.; Buell, J. F.

doi:10.1051/0004-6361:20053590

Cited by 43 publications

(52 citation statements)

References 85 publications

(86 reference statements)

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“…Romano et al (2006), using N yields for LIMSs by van der Hoek & Groenewegen (1997), which are different from those adopted by us, cannot reproduce the N/O values of NGC 1705, a late-type dwarf galaxy. On the other hand, Gavilán et al (2006), using their own N yields, are able to match the present-day N/O value of the solar vicinity, but not the N/O evolution. This problem should be studied further.…”

Section: The N/o Ratiomentioning

confidence: 99%

Chemical and Photometric Evolution of the Local Group Galaxy NGC 6822 in a Cosmological Context

Carigi

Colín

Peimbert

2006

ApJ

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Based on the photometric properties of NGC 6822, we derive a robust star formation history. Adopting this history, we compute 15 models of galactic chemical evolution. All of them match present-day photometric properties. The dark halo mass in all models evolves according to the mass assembly history predicted by a ÃCDM cosmology. We model the evolution of the baryonic mass aggregation history in this cosmological context assuming that part of the gas available for accretion never falls into the system due to two different physical processes. For seven models we assume that during accretion the universal baryon fraction is reduced by reionization only. The best model of this first group, a complex model with an early outflow, fits the observed gaseous mass and the O/H, C/O, and Fe/O present-day values. This model requires a lower upper mass limit for the IMF than that of the solar vicinity, in agreement with recent results by other authors. We have also computed eight models where, in addition to reionization, the accreted baryon fraction is reduced by large-scale shock heating. The best model of this series, which also requires an early outflow and a lower upper mass limit for the IMF, can marginally fit the gaseous mass and the O/ H and C/O observed values.

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Section: The N/o Ratiomentioning

confidence: 99%

Chemical and Photometric Evolution of the Local Group Galaxy NGC 6822 in a Cosmological Context

Carigi

Colín

Peimbert

2006

ApJ

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“…Sources: (Amarsi et al 2015, O, blue and black points) (Ruchti et al 2011, Mg, Si, dark green), (Adibekyan et al 2012, Mg, Si, grey), (González Hernández et al 2013, Mg, Si, orange), (Bensby et al 2014, Mg, Si, blue discs), (Hinkel et al 2014, Mg, Si, purple), (Howes et al 2015, Mg, Si, red circles) , Si, blue circles) Dopita et al (2000); Groves et al (2004); Dopita et al (2013), and Izotov & Thuan (1999)), so we accept this model as a useful description of the scaling behaviour of nitrogen. The observed dispersion in the values of log(N/O), especially at low metallicity, are discussed in Gavilán et al (2006). Clearly, this spread makes specifying a single description problematic, but we use the fit described here, noting that it should be treated as a starting point for modelling, rather than being prescriptive.…”

Section: Carbon and Nitrogenmentioning

confidence: 99%

Abundance scaling in stars, nebulae and galaxies

Nicholls¹,

Sutherland²,

Dopita³

et al. 2016

Mon. Not. R. Astron. Soc.

109

116

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We present a new basis for scaling abundances with total metallicity in nebular photoionisation models, based on extensive Milky Way stellar abundance data, to replace the uniform scaling normally used in the analysis of H ii regions. Our goal is to provide a single scaling method and local abundance reference standard for use in nebular modelling and its key inputs, the stellar atmosphere and evolutionary track models. We introduce a parametric enrichment factor, ζ, to describe how atomic abundances scale with total abundance, and which allows for a simple conversion between scales based on different reference elements (usually oxygen or iron) . The models and parametric description provide a more physically realistic approach than simple uniform abundance scaling. With appropriate parameters, the methods described here may be applied to H ii regions in the Milky Way, large and dwarf galaxies in the local universe, Active Galactic Nuclei (AGNs), and to star forming regions at high redshift.

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“…Solar abundance models are adequate, since there is no evidence that the mean values of [Fe/H] and the metallicity (essentially, the sum of C, N, and O abundances) have changed appreciably in the past $10 Gyr, although there is a considerable and nearly constant scatter over time ( Nordström et al 2004;KarataY et al 2005;Haywood 2006;Gavilán et al 2006). Second-generation models, 2 which take into account line blanketing from iron peak elements, were used in all cases but one.…”

Section: Incident Continuummentioning

confidence: 99%

Photoionization Models Applied to Planetary Nebulae

Bohigas

2008

ApJ

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Good to excellent photoionization models based on the Cloudy code (from Ferland and coworkers) were obtained for 13 out of 19 spectra of planetary nebulae (PNs). Results are deficient when the slit is missing most of the in-depth extent of the ionized region. Features that can be associated to shock excitation and abnormally large helium abundances are found when this is the case. Models assume that the exciting star is a Rauch photosphere illuminating a static uniform density spherical shell. Model central stars lie close to a 2.5 M post-AGB theoretical evolutionary track in the H-R diagram (from Vassiliadis and Wood), with implied PN ages between 1000 and 7000 yr. Observed and modeled nebular temperatures derived from [N ii] kk(6548 þ 6584)/k5755 agree within 10%, but models usually underestimate temperatures found from [O iii] kk(4959 þ 5007)/k4363, more so when the slit does not cover the in-depth extent of the ionized region. Helium, nitrogen, oxygen, neon, sulfur, chlorine, and argon model abundances are uncertain at the 15%, 15%, 10%, 7%, 30%, 5%, and 7% levels, respectively. The following relationships between chemical elements are found: He tends to be more abundant when N/O is large; there is a loose anticorrelation between N/O and O/H; N/C and C/H are anticorrelated; and the sum of the carbon, nitrogen, and oxygen abundances is larger in carbon-rich objects. Finally, it is shown that neon abundance in PNs has been overestimated, and an alternative ionization correction factor is provided.

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Low and intermediate mass star yields

Cited by 43 publications

References 85 publications

Chemical and Photometric Evolution of the Local Group Galaxy NGC 6822 in a Cosmological Context

Chemical and Photometric Evolution of the Local Group Galaxy NGC 6822 in a Cosmological Context

Abundance scaling in stars, nebulae and galaxies

Photoionization Models Applied to Planetary Nebulae

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