The stellar populations and evolution of H II galaxies - I. High signal-to-noise optical spectroscopy

Campbell, Alison; Terlevich, R.; Melnick, J.

doi:10.1093/mnras/223.4.811

Cited by 220 publications

(242 citation statements)

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“…The N/O ratio of 0.07 (assuming N/O = N + /0 + ) in (+007", + 157") is higher than in most H II regions of similar oxygen abundance in irregular galaxies and the outer parts of Scd spirals (e.g., NGC 5471) for which the average value is about 0.03 (Rayo, Peimbert, and TorresPeimbert 1982;Pagel 1985). High N/O ratios resembling the present one are found in II Zw 40 with 12 + log (O/H) = 8.11, N/O = 0.055 (Kunth and Sargent 1983;Campbell, Terlevich, and Melnick 1986), NGC 5253A with 8.14, 0.08 (Campbell et al 1986;Walsh and Roy 1987), and Münch 1 in M 81 with 8.12, 0.10: (Garnett and Shields 1987). Pagel (1987) discussed the alternative possibilities that variable N/O is an age effect (Edmunds and Pagel 1978;Matteucci 1986) or that it is due to local pollution by winds from massive stars.…”

Section: Discussionsupporting

confidence: 64%

The Abundance Gradient in NGC 3344

Vı́lchez¹,

Edmunds²,

Pagel³

1988

PASP

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Section: Discussionsupporting

confidence: 64%

The Abundance Gradient in NGC 3344

Vı́lchez¹,

Edmunds²,

Pagel³

1988

PASP

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“…The gas mass and the ionizing photon Ñux were also derived for each valid solution. All solutions were computed for and 12,500 K. These high tem-T e \ 10,000 peratures have been derived from optical spectroscopy and are consistent with the low metallicity of these two galaxies (Campbell et al 1986 ;Walsh & Roy 1989 ;Kobulnicky et al 1997). Model results for the two galaxies are summarized in Tables 3 and 4.…”

Section: Modeling the H92a Linesupporting

confidence: 54%

Very Large Array Observations of the H92α Line from NGC 5253 and Henize 2‐10: Ionized Gas around Super Star Clusters

Mohan

Anantharamaiah

Goss

2001

ApJ

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We have detected the H92a radio recombination line from two dwarf starburst galaxies, NGC 5253 and He 2-10, using the Very Large Array. Both the line data as well as the radio continuum data are used to model the properties of the ionized gas in the centers of these galaxies. We consider a multidensity model for radio recombination lines and show why previous models, which were based on the assumption of gas at a single density, are valid in many situations. The models show that the ionized gas has a density of D104 cm~3 in both galaxies, with an e †ective size of 2È10 pc and a total mass of D104The derived production rate of Lyman continuum photons is D2.5 ] 1052 s~1 in both the galaxies, M _ . and the corresponding mass of stars (assuming a Salpeter initial mass function) is D105 The M _ . implied stellar density shows that the observed radio recombination lines arise from ionized gas around super star clusters (SSCs) in both galaxies (these SSCs have been recently detected through their radio continuum emission). The existence of D104 of ionized gas within a few parsecs of an SSC places M _ strict constraints on dynamical models. Using simple arguments, the parameter space for a few possible models are derived. The well-known radioÈfar-infrared correlation also holds for NGC 5253, although the radio emission from this galaxy is almost completely thermal. It is shown that NGC 5253 is strong evidence that the component of far-infrared emission from warm dust is correlated separately with the component of radio emission from thermal bremsstrahlung.

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“…Figure 1 formula commonly used (e.g. Campbell et al 1986;Kennicutt et al 2003;Garnett et al 2004a;Bresolin et al 2004), based on the grid of photoionization models by Stasińska (1982). It is seen that, as long as the metallicity is low, the derived O/H value is very close to the input one (the slight deviations seen in Fig.…”

Section: The Biasesmentioning

confidence: 99%

Biases in abundance derivations for metal-rich nebulae

Stasińska¹

2005

A&A

173

211

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Abstract. Using ab-initio photoionization models of giant H  regions, we test methods for abundance determinations based on a direct measurement of the electron temperature, now possible even for moderate to high-metallicity objects. We find that, for metallicities larger than solar, the computed abundances deviate systematically from the real ones, generally by larger amounts for more metal-rich H  regions. We discuss the reasons for this, and present diagrams allowing the reader to better understand the various factors coming into play. We briefly discuss less classical methods to derive abundances in metal-rich H  regions.In particular, we comment on the interest of the oxygen and carbon recombination lines. We also show that, contrary to the case of giant H  regions, the physical conditions in bright extragalactic planetary nebulae are such that their chemical composition can be accurately derived even at high metallicities. Thus, extragalactic planetary nebulae are promising potential probes of the metallicity of the interstellar medium in the internal parts of spiral galaxies as well as in metal-rich elliptical galaxies.

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The stellar populations and evolution of H II galaxies - I. High signal-to-noise optical spectroscopy

Cited by 220 publications

References 0 publications

The Abundance Gradient in NGC 3344

The Abundance Gradient in NGC 3344

Very Large Array Observations of the H92α Line from NGC 5253 and Henize 2‐10: Ionized Gas around Super Star Clusters

Biases in abundance derivations for metal-rich nebulae

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