The SCUBA-2 Cosmology Legacy Survey: the submillimetre properties of Lyman-break galaxies at z = 3-5
The SCUBA-2 Cosmology Legacy Survey: the submillimetre properties of Lyman-break galaxies at z = 3-5
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SCUBA-2 宇宙学遗产巡天：z = 3-5 处莱曼断裂星系的亚毫米特性
DOI：
10.1093/mnras/stu2185
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发表时间：
2015
影响因子：
4.8
通讯作者：
Coppin K
中科院分区：
文献类型：
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作者：
Coppin K
我们给出了在850 μm的莱曼破裂星系(LBG)种群在≈3，4和5的探测结果，这些数据来自于英国红外深空探测超深空探测的亚毫米普通用户测辐射热计阵列2宇宙学遗产调查。我们在探测极限以下用叠加的方法测量了LBGS在3、4和5层的平均850 μm通量密度，典型的紫外光亮度分别为L1700≈、1029erg和S−1 Hz−1。我们测量了850 μm的通量密度，分别为(0.25m±0.03)、(0.41m±0.06)和(0.88m±0.23)mJy，发现它们对850 μm的宇宙远红外(IR)背景的贡献最大为20%。将光谱能量分布的合适范围与z∼3、4、和5个LBG堆叠的24-850 μm通量，我们分别得到了L8-1000 μm≈3.2，5.5和11.0×1011L⊙的红外光度[以及≈50-200 M⊙yr−1的恒星形成率(SFR)]。我们发现，LBGS的红外光度密度的演化与模型预测的从明亮到超明亮的IR星系在这些时期的预期贡献大致一致。我们观察到恒星质量和红外光度之间的正相关关系，并确认，对于固定质量，最红的LBGS(UV斜率β→0)由于尘埃消光而变红，其中最红的LBGS的Sfr(IR)/Sfr(UV)在−2和β上增加了约一个数量级，而Sfr(IR)/Sfr(UV)和∼为20。此外，质量最大的LBG往往具有较高的遮挡比，这暗示着遮挡性质在整个质量范围内存在变化。
We present detections at 850 μm of the Lyman-break galaxy (LBG) population atz≈ 3, 4, and 5 using data from the Submillimetre Common User Bolometer Array 2 Cosmology Legacy Survey in the United Kingdom Infrared Deep Sky Survey ‘Ultra Deep Survey’ field. We employ stacking to probe beneath the survey limit, measuring the average 850 μm flux density of LBGs atz≈ 3, 4, and 5 with typical ultraviolet luminosities ofL1700≈ 1029erg s−1Hz−1. We measure 850 μm flux densities of (0.25 ± 0.03), (0.41 ± 0.06), and (0.88 ± 0.23) mJy, respectively, finding that they contribute at most 20 per cent to the cosmic far-infrared (IR) background at 850 μm. Fitting an appropriate range of spectral energy distributions to thez∼ 3, 4, and 5 LBG stacked 24–850 μm fluxes, we derive IR luminosities ofL8-1000 μm≈ 3.2, 5.5, and 11.0 × 1011L⊙[and star formation rates (SFRs) of ≈50–200 M⊙yr−1], respectively. We find that the evolution in the IR luminosity density of LBGs is broadly consistent with model predictions for the expected contribution of luminous-to-ultraluminous IR galaxies at these epochs. We observe a positive correlation between stellar mass and IR luminosity and confirm that, for a fixed mass, the reddest LBGs (UV slope β → 0) are redder due to dust extinction, with SFR(IR)/SFR(UV) increasing by about an order of magnitude over −2 < β < 0 with SFR(IR)/SFR(UV) ∼ 20 for the reddest LBGs. Furthermore, the most massive LBGs tend to have higher obscured-to-unobscured ratios, hinting at a variation in the obscuration properties across the mass range.