Abundance Gradients in the Galaxy

Rudolph, Alexander; Fich, M.; Bell, G. R.; Norsen, Travis; Simpson, Janet P.; Haas, Michael R.; Erickson, E. F.

doi:10.1086/498869

Cited by 187 publications

(251 citation statements)

References 74 publications

Supporting

Mentioning

220

Contrasting

Unclassified

Order By: Relevance

“…The [O/H] gradients are also reported by several authors (e.g. Smartt & Rolleston 1997;Shaver et al 1983;Rudolph et al 2006), to be between about −0.04 and −0.07 dex kpc −1 at radii 6-18 kpc. The log(C/M) value at radii R g = 2 to 14 kpc in our result has the gradient of ∼0.1 dex kpc −1 , which has an inverse gradient of slope similar in absolute value to that of the metallicity.…”

Section: Discussionsupporting

confidence: 79%

Galactic distributions of carbon- and oxygen-rich AGB stars revealed by the AKARI mid-infrared all-sky survey

Ishihara

Kaneda

Onaka

et al. 2011

A&A

View full text Add to dashboard Cite

Context. The environmental conditions for asympotic giant branch (AGB) stars to reach the carbon-rich (C-rich) phase are important to understand the evolutionary process of AGB stars. The difference between the spatial distributions of C-rich and oxygen-rich (O-rich) AGB stars is essential for the study of the Galactic structure and the chemical evolution of the interstellar medium. Aims. We quantitatively investigate the spatial distributions of C-rich and O-rich AGB stars in our Galaxy. We discuss the difference between them and its origin. Methods. We classify a large number of AGB stars newly detected by the AKARI mid-infrared all-sky survey. In the color-color diagrams, we define their occupation zones based on the locations of known objects. We then obtain the spatial distributions of C-rich and O-rich AGB stars, assuming that they have the same luminosity for a given mass-loss rate. Results. We find that O-rich AGB stars are concentrated toward the Galactic center and that the density decreases with Galactocentric distance, whereas C-rich AGB stars show a relatively uniform distribution within about 8 kpc of Sun. Conclusions. Our result confirms the trends reported in previous studies and extends them to a Galactic scale. We discuss the relations between our result, the Galactic metallicity gradient, and the chemical evolution of the ISM in our Galaxy.

show abstract

Section: Discussionsupporting

confidence: 79%

Galactic distributions of carbon- and oxygen-rich AGB stars revealed by the AKARI mid-infrared all-sky survey

Ishihara

Kaneda

Onaka

et al. 2011

A&A

View full text Add to dashboard Cite

show abstract

“…The first four elements are most readily (but not exclusively) observed in emission-line objects such as H ii regions (Deharveng et al 2000;Rudolph et al 2006) and planetary nebulae (PNe; Henry et al 2004;Perinotto & Morbidelli 2006;Maciel & Costa 2009;Stanghellini & Haywood 2010). Oxygen, the focus of this paper, can also be usefully measured in B dwarf stars (Smartt & Rolleston 1997), while O and Fe can be measured in Cepheid variable stars (Andrievsky et al 2004).…”

Section: Introductionmentioning

confidence: 94%

Abundances of Galactic Anticenter Planetary Nebulae and the Oxygen Abundance Gradient in the Galactic Disk

Henry

Kwitter

Jaskot

et al. 2010

ApJ

121

150

View full text Add to dashboard Cite

We have obtained spectrophotometric observations of 41 anticenter planetary nebulae (PNe) located in the disk of the Milky Way. Electron temperatures and densities, as well as chemical abundances for He, N, O, Ne, S, Cl, and Ar were determined. Incorporating these results into our existing database of PN abundances yielded a sample of 124 well-observed objects with homogeneously determined abundances extending from 0.9 to 21 kpc in galactocentric distance. We performed a detailed regression analysis which accounted for uncertainties in both oxygen abundances and radial distances in order to establish the metallicity gradient across the disk to be 12 + log(O/H) = (9.09 ± 0.05) − (0.058 ± 0.006) × R g , with R g in kpc. While we see some evidence that the gradient steepens at large galactocentric distances, more objects toward the anticenter need to be observed in order to confidently establish the true form of the metallicity gradient. We find no compelling evidence that the gradient differs between Peimbert Types I and II, nor is oxygen abundance related to the vertical distance from the galactic plane. Our gradient agrees well with analogous results for H ii regions but is steeper than the one recently published by Stanghellini & Haywood over a similar range in galactocentric distance. A second analysis using PN distances from a different source implied a flatter gradient, and we suggest that we have reached a confusion limit which can only be resolved with greatly improved distance measurements and an understanding of the natural scatter in oxygen abundances.

show abstract

“…Maciel & Costa (2010) in their review of gradients note that H ii regions yield gradients in the range of −0.044 dex kpc −1 (Esteban et al 2005) to −0.060 dex kpc −1 (Rudolph et al 2006). The more common determination for the oxygen gradient from H ii regions is about −0.04 dex kpc −1 .…”

Section: Light Element Abundances and Gradientsmentioning

confidence: 99%

THE DISTRIBUTION OF THE ELEMENTS IN THE GALACTIC DISK. III. A RECONSIDERATION OF CEPHEIDS FROMl= 30° TO 250°

Luck

Lambert

2011

The Astronomical Journal

213

267

View full text Add to dashboard Cite

This paper reports on the spectroscopic investigation of 238 Cepheids in the northern sky. Of these stars, about 150 are new to the study of the galactic abundance gradient. These new Cepheids bring the total number of Cepheids involved in abundance distribution studies to over 400. In this work, we also consider systematics between various studies and also those which result from the choice of models. We find that systematic variations exist at the 0.06 dex level both between studies and model atmospheres. In order to control the systematic effects our final gradients depend only on abundances derived herein. A simple linear fit to the Cepheid data from 398 stars yields a gradient d[Fe/H]/dR G = −0.062 ± 0.002 dex kpc −1 which is in good agreement with previously determined values. We have also re-examined the region of the "metallicity island" of Luck et al. With the doubling of the sample in that region and our internally consistent abundances, we find that there is scant evidence for a distinct island. We also find in our sample the first reported Cepheid (V1033 Cyg) with a pronounced Li feature. The Li abundance is consistent with the star being on its redward pass toward the first giant branch.

show abstract

Abundance Gradients in the Galaxy

Cited by 187 publications

References 74 publications

Galactic distributions of carbon- and oxygen-rich AGB stars revealed by the AKARI mid-infrared all-sky survey

Galactic distributions of carbon- and oxygen-rich AGB stars revealed by the AKARI mid-infrared all-sky survey

Abundances of Galactic Anticenter Planetary Nebulae and the Oxygen Abundance Gradient in the Galactic Disk

THE DISTRIBUTION OF THE ELEMENTS IN THE GALACTIC DISK. III. A RECONSIDERATION OF CEPHEIDS FROMl= 30° TO 250°

Contact Info

Product

Resources

About