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We present results on the star-formation rate (SFR) versus stellar mass (M_*) relation (i. e. , the "main sequence") among star-forming galaxies at 1. 37z2. 61 using the MOSFIRE Deep Evolution Field (MOSDEF) survey. Based on a sample of 261 galaxies with H and H spectroscopy, we have estimated robust dust-corrected instantaneous SFRs over a large range in M_* (10^9. 5-10^11. 5M_). We find a correlation between log (SFR (H) ) and log (M_*) with a slope of 0. 650. 08 (0. 580. 10) at 1. 4<z<2. 6 (2. 1<z<2. 6). We find that different assumptions for the dust correction, such as using the color-excess of the stellar continuum to correct the nebular lines, sample selection biases against red star-forming galaxies, and not accounting for Balmer absorption can yield steeper slopes of the log (SFR) -log (M_*) relation. Our sample is immune from these biases as it is rest-frame optically selected, H and H are corrected for Balmer absorption, and the H luminosity is dust-corrected using the nebular color-excess computed from the Balmer decrement. The scatter of the log (SFR (H) ) -log (M_*) relation, after accounting for the measurement uncertainties, is 0. 31 dex at 2. 1<z<2. 6, which is 0. 05 dex larger than the scatter in log (SFR (UV) ) -log (M_*). Based on comparisons to a simulated SFR-M_* relation with some intrinsic scatter, we argue that in the absence of direct measurements of galaxy-to-galaxy variations in the attenuation/extinction curves and the IMF, one cannot use the difference in the scatter of the SFR (H) - and SFR (UV) -M_* relations to constrain the stochasticity of star formation in high-redshift galaxies.
Shivaei et al. (Mon,) studied this question.