论文标题
叛军阿尔玛调查：宇宙尘埃温度演变为z $ \ sim $ 7
The REBELS ALMA Survey: cosmic dust temperature evolution out to z $\sim$ 7
论文作者
论文摘要
阿尔玛（Alma）的观察结果揭示了宇宙中第一代星系中存在灰尘。但是，由于RedShift $ Z> 5 $的少数可用的FIR连续数据，尘埃温度$ t_d $仍然不受约束。这引入了高$ z $星系的几种属性中的大型不确定性，即它们的尘埃质量，红外亮度和恒星形成的晦涩。使用基于同时[CII] 158 $μm线的新方法和基础尘埃连续测量，我们在连续体中得出$ t_ d $，[CII]检测到了Alma大型项目Rebels样本中的$ Z \ 7 $星系。 We find $39\ \mathrm{K} < T_d < 58\ \mathrm{K}$, and dust masses in the narrow range $M_d = (0.9-3.6)\times 10^7 M_{\odot}$.这些结果使我们能够首次扩展到报告的$ T_D（Z）$之间的关系到电源时期。我们产生了一个新的物理模型，该模型解释了$ t_ d（z）$趋势的增加，而气体耗尽时间的减少，$ t_ {dep} = m_g/\ mathrm {sfr} $，由较高的宇宙学积聚率在早期时间引起；该假设产生$ T_D \ Propto（1+Z）^{0.4} $。该模型还解释了观察到的$ t_d $散布在固定的红移中。我们发现，在被模糊的来源中，灰尘会变得更温暖，因为较大的遮挡导致更有效的灰尘加热。对于UV-Transparent（模糊的）星系，$ T_D $仅取决于气柱密度（金属性），$ T_D \ Propto N_H^{1/6} $（$ T_D \ Propto Z^{ - 1/6} $）。叛军星系平均相对透明，有效的气柱密度左右$ n_h \ simeq（0.03-1）\ times 10^{21} \ Mathrm {cm}^{ - 2} $。我们预测，其他高$ z $星系（例如MacS0416-Y1，A2744-YD4），估计$ T_D \ gg 60 $ k，是显着模糊的，低金属的系统。实际上，由于其较小的灰尘含量，金属贫困系统的$ t_d $较高，这对$ l_ {ir} $固定会导致温度较高。
ALMA observations have revealed the presence of dust in the first generations of galaxies in the Universe. However, the dust temperature $T_d$ remains mostly unconstrained due to the few available FIR continuum data at redshift $z>5$. This introduces large uncertainties in several properties of high-$z$ galaxies, namely their dust masses, infrared luminosities, and obscured fraction of star formation. Using a new method based on simultaneous [CII] 158$μ$m line and underlying dust continuum measurements, we derive $T_ d$ in the continuum and [CII] detected $z\approx 7$ galaxies in the ALMA Large Project REBELS sample. We find $39\ \mathrm{K} < T_d < 58\ \mathrm{K}$, and dust masses in the narrow range $M_d = (0.9-3.6)\times 10^7 M_{\odot}$. These results allow us to extend for the first time the reported $T_d(z)$ relation into the Epoch of Reionization. We produce a new physical model that explains the increasing $T_ d(z)$ trend with the decrease of gas depletion time, $t_{dep}=M_g/\mathrm{SFR}$, induced by the higher cosmological accretion rate at early times; this hypothesis yields $T_d \propto (1+z)^{0.4}$. The model also explains the observed $T_d$ scatter at a fixed redshift. We find that dust is warmer in obscured sources, as a larger obscuration results in more efficient dust heating. For UV-transparent (obscured) galaxies, $T_d$ only depends on the gas column density (metallicity), $T_d \propto N_H^{1/6}$ ($T_d \propto Z^{-1/6}$). REBELS galaxies are on average relatively transparent, with effective gas column densities around $N_H \simeq (0.03-1)\times 10^{21} \mathrm{cm}^{-2}$. We predict that other high-$z$ galaxies (e.g. MACS0416-Y1, A2744-YD4), with estimated $T_d \gg 60$ K, are significantly obscured, low-metallicity systems. In fact $T_d$ is higher in metal-poor systems due to their smaller dust content, which for fixed $L_{ IR}$ results in warmer temperatures.
