DISSECTING THE STELLAR-MASS–SFR CORRELATION IN z = 1 STAR-FORMING DISK GALAXIES
DISSECTING THE STELLAR-MASS–SFR CORRELATION IN z = 1 STAR-FORMING DISK GALAXIES
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DOI：
10.1088/2041-8205/754/1/l14
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发表时间：
2012-06
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影响因子：
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通讯作者：
F. Salmi;E. Daddi;D. Elbaz;M. Sargent;M. Dickinson;A. Renzini;M. Béthermin;D. Le Borgne
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文献类型：
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作者：
F. Salmi;E. Daddi;D. Elbaz;M. Sargent;M. Dickinson;A. Renzini;M. Béthermin;D. Le Borgne
利用一个24 μm的有限质量样本，研究了质量-恒星形成率（SFR）的相关性及其紧密性。对于盘状星系（nSérsic < 1.5），相关性很好（σ = 0.28 dex），而更多的膨胀主导天体通常具有较低的比SFR（sSFR）。对于盘星系，如果用静止坐标系H带光度代替多色测光得到的恒星质量，则得到更紧密的相关性（σ = 0.19 dex）。sSFR与静止坐标系的光学颜色（因此是光度加权的恒星年龄）和团块（可能反映了分子气体部分）密切相关。这意味着大多数观察到的散射是真实的，尽管其水平较低，而不是由随机测量误差主导。在对这些微分效应进行校正后，仍然存在非常小的色散（σ = 0.14 dex），这表明质量或SFR的测量误差为≤ 0.10 dex，不包括系统不确定性。恒星质量的测量误差、由于真实的sSFR变化而导致的相关性变厚，以及随着恒星质量的变化而变化的完整性，由于可观测量（质量和SFR）的有限范围，可能会使导出的斜率虚假地偏置到较低值。当考虑到这些影响时，盘状星系主序的内禀斜率更接近于1。
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 (nSérsic < 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.