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Title: THE MASS-METALLICITY RELATION OF A z {approx} 2 PROTOCLUSTER WITH MOSFIRE

We present Keck/MOSFIRE observations of the role of environment in the formation of galaxies at z {approx} 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 with respect to environment at z {approx} 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 massivemore » galaxies. Future hydrodynamical simulations of z {approx} 2 overdensities matching the one in the HS1700 field will be crucial for understanding the origin of the observed environmental trend in detail.« less
Authors:
; ; ;  [1] ; ; ; ; ;  [2] ;  [3]
  1. Department of Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095 (United States)
  2. California Institute of Technology, MS 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
  3. Department of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521 (United States)
Publication Date:
OSTI Identifier:
22133889
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 774; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BALMER LINES; GALAXIES; GALAXY CLUSTERS; HYDRODYNAMIC MODEL; MASS; METALS; RED SHIFT; SPECTROSCOPY