Galaxy metallicities depend primarily on stellar mass and molecular gas mass
| Autor: | Matt Bothwell, Jeff Wagg, Roberto Maiolino, Y. Peng, Claudia Cicone |
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| Přispěvatelé: | Maiolino, Roberto [0000-0002-4985-3819], Apollo - University of Cambridge Repository |
| Rok vydání: | 2016 |
| Předmět: |
Stellar mass
Metallicity FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Parameter space 01 natural sciences 0103 physical sciences 10. No inequality 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics galaxies: statistics Physics 010308 nuclear & particles physics Star formation Plane (geometry) Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Galaxy Redshift Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Outflow galaxies: abundances galaxies: evolution galaxies: ISM |
| Popis: | In this work we present an analysis of the behaviour of galaxies in a four-dimensional parameter space defined by stellar mass, metallicity, star formation rate, and molecular gas mass. We analyse a combined sample of 227 galaxies, which draws from a number of surveys across the redshift range 0 < z < 2 (> 90% of the sample at z~0), and covers > 3 decades in stellar mass.Using Principle Component Analysis, we demonstrate that galaxies in our sample lie on a 2-dimensional plane within this 4D parameter space, indicative of galaxies that exist in an equilibrium between gas inflow and outflow. Furthermore, we find that the metallicity of galaxies depends only on stellar mass and molecular gas mass. In other words, gas-phase metallicity has a negligible dependence on star formation rate, once the correlated effect of molecular gas content is accounted for. The well-known `fundamental metallicity relation', which describes a close and tight relationship between metallicity and SFR (at fixed stellar mass) is therefore entirely a by-product of the underlying physical relationship with molecular gas mass (via the Schmidt-Kennicutt relation). 5 pages, 2 figures. Accepted for publication in A&A |
| Databáze: | OpenAIRE |
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