THE STELLAR MASS CONTENT OF SUBMILLIMETER-SELECTED GALAXIES
THE STELLAR MASS CONTENT OF SUBMILLIMETER-SELECTED GALAXIES
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DOI：
10.1088/0004-637x/740/2/96
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发表时间：
2010-06
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影响因子：
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通讯作者：
L. Hainline;A. Blain;I. Smail;D. Alexander;L. Armus;S. Chapman;R. Ivison
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文献类型：
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作者：
L. Hainline;A. Blain;I. Smail;D. Alexander;L. Armus;S. Chapman;R. Ivison
我们在具有精确光谱红移的约70个亚毫米选择星系（smg）样本中提出了一项新的恒星质量研究。我们通过中红外光谱能量分布（SEDs）将恒星种群综合模型和幂律组合拟合到星系的观测框架光学中，以分离恒星发射和非恒星近红外连续体。光谱红移的可用性大大提高了我们的能力，不仅可以明确地确定smg的质量和亮度，还可以确定非恒星辐射对其SEDs的存在和贡献。通过将恒星发射与非恒星近红外连续体分离，我们发现样品中~ 50%的样品在静止框架H波段的非恒星贡献小于10%，并且样品中~ 10%的样品的非恒星贡献大于50%。我们发现非恒星连续发射的k波段光度与硬x射线光度相关，表明发射的活动星系核（AGN）起源。在从我们样本中的所有星系中减去agn贡献的连续体成分后，我们确定smg的中位数恒星质量比以前的研究低，约7 × 1010 M☉。我们使用来自分子气体研究的星暴时间尺度的约束来估计如果我们的样本在星暴结束后被动进化，它们将经历的褪色量。结果表明，典型的smg，虽然在z ~ 2的最大质量星系中，可能会产生与本地宇宙中L*星系相似的质量和光度的后代。
We present a new study of stellar mass in a sample of ∼70 submillimeter-selected galaxies (SMGs) with accurate spectroscopic redshifts. We fit combinations of stellar population synthesis models and power laws to the galaxies' observed-frame optical through mid-IR spectral energy distributions (SEDs) to separate stellar emission from non-stellar near-IR continuum. The availability of spectroscopic redshifts significantly enhances our ability to determine unambiguously not only the mass and luminosity of SMGs, but also the presence and contribution of non-stellar emission to their SEDs. By separating the stellar emission from the non-stellar near-IR continuum, we find that ∼50% of our sample have non-stellar contributions of less than 10% in rest-frame H band and ∼10% of our sample have non-stellar contributions greater than 50%. We find that the K-band luminosity of the non-stellar continuum emission is correlated with hard X-ray luminosity, indicating an active galactic nucleus (AGN) origin of the emission. Upon subtracting this AGN-contributed continuum component from all of the galaxies in our sample, we determine a lower median stellar mass for SMGs than previous studies, ∼7 × 1010 M☉. We use constraints of the starburst timescale from molecular gas studies to estimate the amount of fading our sample would undergo if they passively evolve after the starburst terminates. The results suggest that typical SMGs, while among the most massive galaxies at z ∼ 2, are likely to produce descendants of similar mass and luminosity to L* galaxies in the local universe.