The Chemical Evolution of the Galaxy with Variable IMFs

Abstract

In this work we explore the effects of adopting initial mass functions (IMFs) variable in time on the chemical evolution of the Galaxy. In order to do that we adopt a chemical evolution model which assumes two main infall episodes for the formation of the Galaxy and which proved to be successful in reproducing the majority of the observational constraints, at least for the case of a constant IMF. Different variable IMFs are tested with this model, all assuming that massive stars are preferentially formed in ambients of low metallicity. This implies that massive stars are formed preferentially at early times and at large galactocentric distances. Our numerical results have shown that all the variable IMFs proposed so far are unable to reproduce all the relevant observational constraints in the Galaxy and that a constant IMF still reproduces better the observations. In particular, variable IMFs of the kind explored here are unable to reproduce the observed abundance gradients even when allowing for changes in other chemical evolution model parameters as, for instance, the star formation rate. As a consequence of this we conclude that the G-dwarf metallicity distribution is best explained by infall with a large timescale and a constant IMF, since it is possible to find variable IMFs of the kind studied here, reproducing the G-dwarf metallicity but this worsen the agreement with other observational constraints.

34 pages, 13 figures, ApJ (in press)

References in corpus (10)

• The Global Schmidt Law in Star Forming Galaxies
• The Chemical Evolution of the Galaxy: the two-infall model
• The Universality of the Stellar IMF
• Early Star Formation and the Evolution of the Stellar Initial Mass Function in Galaxies
• High Velocity Clouds: Building Blocks of the Local Group
• On the Density Probability Function of Galactic Gas. I. Numerical Simulations and the Significance of the Polytropic Index
• The metallicity distribution of G dwarfs in the solar neighbourhood
• The Earliest Phases of Galaxy Evolution
• Is High Primordial Deuterium Consistent With Galactic Evolution?
• The Local Abundance of ${}^3$He: A Confrontation Between Theory and Observation

Cited by in corpus (33)

• The Initial Mass Function of Stars: Evidence for Uniformity in Variable Systems
• Origin of the Heaviest Elements: the Rapid Neutron-Capture Process
• Abundance Gradients and the Formation of the Milky Way
• Chemical enrichment of galaxy clusters from hydrodynamical simulations
• Oxygen, Carbon and Nitrogen evolution in galaxies
• Chemical similarities between Galactic bulge and local thick disk red giant stars
• The Halo Stars in NGC 5128. III: An Inner-Halo Field and the Metallicity Distribution
• A revision of the solar neighbourhood metallicity distribution
• Transition of the initial mass function in the metal-poor environments
• Stellar Iron Abundances at the Galactic Center
• Galactic chemical abundance evolution in the solar neighborhood up to the Iron peak
• The Metallicity Distribution Functions of SEGUE G and K dwarfs: Constraints for Disk Chemical Evolution and Formation
• What determines galactic evolution?
• Evolution of Deuterium, 3He and 4He in the Galaxy
• Chemical evolution in a model for the joint formation of quasars and spheroids
• The influence of binaries on galactic chemical evolution
• Galactic Chemical Evolution
• M31's Heavy Element Distribution and Outer Disk
• The Gaia-ESO Survey: Insights on the inner-disc evolution from open clusters
• The puzzlingly large Ca II triplet absorption in dwarf elliptical galaxies
• The origin of carbon: Low-mass stars and an evolving, initially top-heavy IMF?
• Abundances in the Galactic bulge: results from planetary nebulae and giant stars
• The Chemical Evolution of the Milky Way: the Three Infall Model
• Sources of carbon and the evolution of the abundance of CNO elements
• Effects of the integrated galactic IMF on the chemical evolution of the solar neighbourhood
• The Chemical Evolution of the Milky Way
• Testing Stellar Population Fitting Ingredients with Globular Clusters I: Stellar Libraries
• The connection between Gamma-ray bursts and Supernovae Ib/c
• Nitrogen Production in Starburst Galaxies Detected by GALEX
• Galactic dust evolution with rapid dust formation in the interstellar medium due to hypersonic turbulence
• PN-Carbon Yields and the Chemical Evolution of the Galactic Disk
• Ionised gas abundances in barred spiral galaxies
• Neutron-capture elements record the ordered chemical evolution of the disc over time