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Title: The relationship between stellar mass, gas metallicity, and star formation rate for Hα-selected galaxies at z ≈ 0.8 from the NewHα survey

Using a sample of 299 Hα-selected galaxies at z≈0.8, we study the relationship between galaxy stellar mass, gas-phase metallicity, and star formation rate (SFR), and compare to previous results. We use deep optical spectra obtained with the IMACS spectrograph at the Magellan telescope to measure strong oxygen lines. We combine these spectra and metallicities with (1) rest-frame UV-to-optical imaging, which allows us to determine stellar masses and dust attenuation corrections, and (2) Hα narrowband imaging, which provides a robust measurement of the instantaneous SFR. Our sample spans stellar masses of ∼10{sup 9}–6 × 10{sup 11} M{sub ⊙}, SFRs of 0.4–270 M{sub ⊙} yr{sup −1}, and metal abundances of 12+log(O/H)≈8.3–9.1 (≈0.4–2.6 Z{sub ⊙}). The correlations that we find between the Hα-based SFR and stellar mass (i.e., the star-forming “main sequence”) and between the stellar mass and metallicity are both consistent with previous z∼1 studies of star-forming galaxies. We then study the relationship between the three properties using various plane-fitting techniques and a curve-fitting projection. In all cases, we exclude strong dependence of the M{sub ⋆}–Z relation on SFR, but are unable to distinguish between moderate and no dependence. Our results are consistent with previous mass–metallicity–SFR studies. We check whether data setmore » limitations may obscure a strong dependence on the SFR by using mock samples drawn from the Sloan Digital Sky Survey. These experiments reveal that the adopted signal-to-noise ratio cuts may have a significant effect on the measured dependence. Further work is needed to investigate these results, and to test whether a “fundamental metallicity relation” or a “fundamental plane” describes star-forming galaxies across cosmic time.« less
Authors:
 [1] ; ; ; ;  [2] ;  [3] ;  [4] ;  [5] ; ;  [6] ;  [7]
  1. Department of Physics, North Carolina State University, Raleigh, NC (United States)
  2. Space Telescope Science Institute, Baltimore, MD (United States)
  3. Astronomy Department, Indiana University, Bloomington, IN (United States)
  4. Astronomy Department, Yale University, New Haven, CT (United States)
  5. Department of Physics and Astronomy, University of Wyoming, Laramie, WY (United States)
  6. Institute for the Physics and Mathematics of the Universe, TODIAS, University of Tokyo (Japan)
  7. Physics Department of Physics and Astronomy, Siena College, Loudonville, NY (United States)
Publication Date:
OSTI Identifier:
22342099
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 149; 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; ABUNDANCE; ATTENUATION; COMPARATIVE EVALUATIONS; CORRECTIONS; CORRELATIONS; DUSTS; EVOLUTION; GALAXIES; MASS; METALLICITY; METALS; OXYGEN; SIGNAL-TO-NOISE RATIO; SPECTRA; STAR EVOLUTION; STARS; TELESCOPES