Dissecting the Stellar-Mass-Sfr Correlation in Z = 1 Star-Forming Disk Galaxies - CEA - Commissariat à l’énergie atomique et aux énergies alternatives
Journal Articles The Astrophysical journal letters Year : 2012

Dissecting the Stellar-Mass-Sfr Correlation in Z = 1 Star-Forming Disk Galaxies

Abstract

Using a mass-limited sample of 24 μm detected, star-forming galaxies at 0.5 < z < 1.3, we study the mass-star formation rate (SFR) correlation and its tightness. The correlation is well defined (σ = 0.28 dex) for disk galaxies (n Sérsic < 1.5), while more bulge-dominated objects often have lower specific SFRs (sSFRs). For disk galaxies, a much tighter correlation (σ = 0.19 dex) is obtained if the rest-frame H-band luminosity is used instead of stellar mass derived from multi-color photometry. The sSFR correlates strongly with rest-frame optical colors (hence luminosity-weighted stellar age) and also with clumpiness (which likely reflects the molecular gas fraction). This implies that most of the observed scatter is real, despite its low level, and not dominated by random measurement errors. After correcting for these differential effects a remarkably small dispersion remains (σ = 0.14 dex), suggesting that measurement errors in mass or SFR are 0.10 dex, excluding systematic uncertainties. Measurement errors in stellar masses, the thickening of the correlation due to real sSFR variations, and varying completeness with stellar mass, can spuriously bias the derived slope to lower values due to the finite range over which observables (mass and SFR) are available. When accounting for these effects, the intrinsic slope for the main sequence for disk galaxies gets closer to unity.

Dates and versions

cea-00832919 , version 1 (11-06-2013)

Identifiers

Cite

F. Salmi, Emanuele Daddi, D. Elbaz, M. T. Sargent, M. Dickinson, et al.. Dissecting the Stellar-Mass-Sfr Correlation in Z = 1 Star-Forming Disk Galaxies. The Astrophysical journal letters, 2012, 754 (1), pp.L14. ⟨10.1088/2041-8205/754/1/L14⟩. ⟨cea-00832919⟩
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