The Mass-Metallicity Relation Of A Z~2 Protocluster With MOSFIRE
| Autor: | Ian S. McLean, Gwen C. Rudie, Ryan F. Trainor, Kristin R. Kulas, Keith Matthews, Alice E. Shapley, Gregory N. Mace, Naveen A. Reddy, Nicholas P. Konidaris, Charles C. Steidel |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Stellar mass Field (physics) Metallicity FOS: Physical sciences Astronomy and Astrophysics Context (language use) Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Galaxy Space and Planetary Science Galaxy formation and evolution Emission spectrum Spectroscopy Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Popis: | We present Keck/MOSFIRE observations of the role of environment in the formation of galaxies at z~2. Using K-band spectroscopy of H-alpha and [N II] emission lines, we have analyzed the metallicities of galaxies within and around a z=2.3 protocluster discovered in the HS1700+643 field. Our main sample consists of 23 protocluster and 20 field galaxies with estimates of stellar masses and gas-phase metallicities based on the N2 strong-line metallicity indicator. With these data we have examined the mass-metallicity relation (MZR) with respect to environment at z~2. We find that field galaxies follow the well-established trend between stellar mass and metallicity, such that more massive galaxies have larger metallicities. The protocluster galaxies, however, do not exhibit a dependence of metallicity on mass, with the low-mass protocluster galaxies showing an enhancement in metallicity compared to field galaxies spanning the same mass range. A comparison with galaxy formation models suggests that the mass-dependent environmental trend we observed can be qualitatively explained in the context of the recycling of "momentum-driven" galaxy wind material. Accordingly, winds are recycled on a shorter timescale in denser environments, leading to an enhancement in metallicity at fixed mass for all but the most massive galaxies. Future hydrodynamical simulations of z~2 overdensities matching the one in the HS1700 field will be crucial for understanding the origin of the observed environmental trend in detail. 9 pages, 4 figures, accepted to ApJ |
| Databáze: | OpenAIRE |
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