Book contents
- Frontmatter
- Contents
- Participants
- Preface
- History of the Local Group
- Primordial nucleosynthesis
- Galactic structure
- The Large Magellanic Cloud: Structure and kinematics
- The Local Group as an astrophysical laboratory for massive star feedback
- Hot gas in the Local Group and low-redshift intergalactic medium
- Stages of satellite accretion
- The star formation history in the Andromeda halo
- Bulge populations in the Local Group
- The Local Group as a laboratory for the chemical evolution of galaxies
- Massive stars in the Local Group: Star formation and stellar evolution
- Massive Young Clusters in the Local Group
- Magellanic Cloud planetary nebulae as probes of stellar evolution and populations
- The old globular clusters: Or, life among the ruins
- Chemical evolution models of Local Group galaxies
The Local Group as a laboratory for the chemical evolution of galaxies
Published online by Cambridge University Press: 12 May 2010
- Frontmatter
- Contents
- Participants
- Preface
- History of the Local Group
- Primordial nucleosynthesis
- Galactic structure
- The Large Magellanic Cloud: Structure and kinematics
- The Local Group as an astrophysical laboratory for massive star feedback
- Hot gas in the Local Group and low-redshift intergalactic medium
- Stages of satellite accretion
- The star formation history in the Andromeda halo
- Bulge populations in the Local Group
- The Local Group as a laboratory for the chemical evolution of galaxies
- Massive stars in the Local Group: Star formation and stellar evolution
- Massive Young Clusters in the Local Group
- Magellanic Cloud planetary nebulae as probes of stellar evolution and populations
- The old globular clusters: Or, life among the ruins
- Chemical evolution models of Local Group galaxies
Summary
I review what is known about the general trends of metallicity and element abundance ratios in Local Group galaxies, and some implications of the abundance trends for chemical evolution. The Local Group spirals show radial metallicity gradients and a mean metallicity that increases with luminosity. The composition gradients steepen with decreasing galaxy luminosity, but are roughly similar when the gradients are derived per unit disk scale length. This suggests that the evolution of the metallicity gradient is closely tied to the evolution of the baryon distribution. The M31 and MilkyWay bulges appear to have similar metallicity distributions. The high [α/Fe] in Galactic bulge stars indicates that the bulge formed rapidly. Metallicity distributions for M31 and Galactic halo stars are also similar, except that M31 has more globular clusters that are metal-rich, possibly related to its larger bulge. M33 is anomalous in that its halo clusters may be significantly younger than the Galactic halo. Local Group irregular galaxies are metal-poor, and their mean metallicity correlates with galaxy luminosity. They have low effective yields, as derived from a comparison of mean metallicity with gas fraction, and the effective yield is correlated with galaxy rotation speed (or mass). This is evidence that the irregulars have lost metals to the IGM, either through galactic winds or stripping. Dwarf ellipticals in the Local Group are also metal-poor, and follow a similar metallicity-luminosity relation. The fact that the dEs have no gas also points to loss of metals as a significant factor in their evolution.
- Type
- Chapter
- Information
- The Local Group as an Astrophysical LaboratoryProceedings of the Space Telescope Science Institute Symposium, held in Baltimore, Maryland May 5–8, 2003, pp. 140 - 163Publisher: Cambridge University PressPrint publication year: 2006