Cartas al Editor

Delgado, M. González; Torres, Rosa Antón; Blasco, Joaquín Borrás; Sandomingo, Vega Ortiz de Urbina

doi:10.1016/s0025-7753(00)71293-0

Cited by 2 publications

(5 citation statements)

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“…Since there was little or no He II emission, the ionization correction factor could be assumed to be unity. 6. derived properties Derived properties for the five dIs observed at Steward and OAN are listed in Table 19.…”

Section: Oxygen Abundancesmentioning

confidence: 99%

“…The oxygen abundance for the brighter H II region UGC 6456-2 (12+log(O/H) = 7.45) was adopted for the present work. Izotov, Thuan, & Lipovetsky (1997), Lynds et al (1998), provide more recent measurements. A homogeneous treatment of these data gives oxygen abundances of 12+log(O/H) = 7.65, 7.74, and 7.73, respectively.…”

Section: Ugc 6456mentioning

confidence: 99%

“…dEs and dSphs, respectively, are the bright and faint representatives of gas-poor dwarf galaxies in which star formation has ceased (e.g., Binggeli, Sandage, & Tarenghi 1984;Kormendy 1985;Bender, Burstein, & Faber 1992;Binggeli 1994). In all of these types of dwarf galaxies, central surface brightness increases with increasing luminosity 6 . It seems natural to consider a possible evolutionary relationship between dIs and dEs/dSphs (e.g., Bothun et al 1986;Dekel & Silk 1986;Davies & Phillipps 1988Ferguson & Binggeli 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Column (5): Observed Hβ emission equivalent width. Column (6): Computed O +2 electron temperature, assuming an electron density of 100 cm −3 . Column (7): Derived oxygen abundance.…”

mentioning

confidence: 99%

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Uncovering Additional Clues to Galaxy Evolution. I. Dwarf Irregular Galaxies in the Field

Lee

McCall

Kingsburgh

et al. 2003

The Astronomical Journal

156

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In order to recognize environmental effects on the evolution of dwarf galaxies in clusters of galaxies, it is first necessary to quantify the properties of objects which have evolved in relative isolation. With oxygen abundance as the gauge of metallicity, two key diagnostics of the evolution of dwarf irregular galaxies in the field are re-examined: the metallicity-luminosity relationship and the metallicity-gas fraction relationship. Gas fractions are evaluated from the masses of luminous components only, i.e., constituents of the nucleogenetic pool. Results from new optical spectroscopy obtained for H II regions in five dwarf irregular galaxies in the Local Volume are incorporated into a new analysis of field dwarfs with [O III]λ4363 detections and good distances. The updated fit to the metallicity-luminosity relationship is consistent with results reported in the literature. The fit to the metallicity-gas fraction relation shows an excellent correlation consistent with expectations of the simple "closed box" model of chemical evolution. The simplest explanation consistent with the data is that flow rates are zero, although the observations allow for the possibility of modest flows. The derived oxygen yield is one-quarter of the value for the solar neighbourhood. 6 Low-luminosity ellipticals or LLEs (e.g., M32) are structurally similar to giant ellipticals and exhibit a trend of decreasing surface brightness with increasing luminosity.

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Section: Oxygen Abundancesmentioning

confidence: 99%

Section: Ugc 6456mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Column (5): Observed Hβ emission equivalent width. Column (6): Computed O +2 electron temperature, assuming an electron density of 100 cm −3 . Column (7): Derived oxygen abundance.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Uncovering Additional Clues to Galaxy Evolution. I. Dwarf Irregular Galaxies in the Field

Lee

McCall

Kingsburgh

et al. 2003

The Astronomical Journal

156

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“…Morton et al 1980). In a recent study, González-Delgado et al (1998) have detected interstellar absorption lines towards the bright starburst nucleus of NGC 7714 in the ultraviolet spectrum taken with the Hubble Space Telescope. Hence, when background sources are available the present technology allows for the measurement of interstellar absorption lines.…”

Section: Discussionmentioning

confidence: 99%

Chemical Abundance Gradients in the Star‐forming Ring Galaxies

Корчагин

Vorobyov

Mayya

1999

ApJ

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Ring waves of star formation, propagating outwardly in the galactic disks, leave chemical abundance gradients in their wakes. We show that the relative [F e/O] abundance gradients in ring galaxies can be used as a tool for determining the role of the SNIa explosions in their chemical enrichment. We consider two mechanisms which can create outwardly propagating star forming rings in a purely gaseous disk -a self-induced wave and a density wave, and demonstrate that the radial distribution of the relative [F e/O] abundance gradients does not depend on the particular mechanism of the wave formation or on the parameters of the star-forming process. We show that the [F e/O] profile is determined by the velocity of the wave, initial mass function, and the initial chemical composition of the star-forming gas. If the role of SNIa explosions is negligible in the chemical enrichment, the ratio [F e/O] remains constant throughout the galactic disk with a steep gradient at the wave front. If SNIa stars are important in the production of cosmic iron, the [F e/O] ratio has gradient in the wake of the star-forming wave with the value depending on the frequency of SNIa explosions.

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Cartas al Editor

Cited by 2 publications

References 0 publications

Uncovering Additional Clues to Galaxy Evolution. I. Dwarf Irregular Galaxies in the Field

Uncovering Additional Clues to Galaxy Evolution. I. Dwarf Irregular Galaxies in the Field

Chemical Abundance Gradients in the Star‐forming Ring Galaxies

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