论文标题
微弱的无线电天空（Cosmos-XS）的超深度vla调查：宇宙星形成历史的新约束
An ultra-deep multi-band VLA survey of the faint radio sky (COSMOS-XS): New constraints on the cosmic star formation history
论文作者
论文摘要
我们利用超深的3 GHz Karl G. Jansky对宇宙场的阵列观测非常大，从多波段Cosmos-XS调查到推断星形星系（SFGS）的无线电光度函数（LFS）。使用$ \ sim $ 1300 sfgs，红移将$ z \ sim4.6 $排出，并将无线电LF的淡淡而明亮的最终形状固定在本地值中，我们发现了一个强烈的红移趋势，可以通过纯亮度进化来拟合纯度的亮度进化，并通过$α_l\ propto（3.40 \ pm pm pm 0.11）（0.48 Z）拟合亮度进化，并将其固定为uminusity速度。然后，我们将Ultra-Deep Cosmos-XS数据集与较浅的VLA-COSMOS $ \ MATHRM {3 \，GHz} $大于更广泛的COSMOS字段上的大型项目数据集相结合，以适合关节密度+亮度的演化，以寻找大量密度演化的证据。通过将无线电LFS与观察到的远红外（FIR）和紫外线（UV）LFS进行比较，我们发现证据表明，在高红色Shift（$ 3.3 \，<，pow，$ 3.3 \，<3.3 \，<3.3 \，<3.3 \，<3.3 \，<\，4.6 $，4.6 $，4.6 $，4.6 $，4.6 $，4.3 $ 0.03 \，l^{\ star} _ {z = 3} $）。我们通过集成拟合的无线电LFS来得出宇宙星形成速率密度（SFRD），并发现SFRD上升到$ z \，\ sim \，1.8 $，然后比以前基于无线电的估计值更快地下降。 A direct comparison between the radio SFRD and a recent UV-based SFRD, where we integrate both LFs down to a consistent limit ($0.038\,L^{\star}_{z=3}$), reveals that the discrepancy between the radio and UV LFs translates to a significant ($\sim$1 dex) discrepancy in the derived SFRD at $z>3$, even assuming the最新的灰尘校正，而无需考虑光学深色的来源。
We make use of ultra-deep 3 GHz Karl G. Jansky Very Large Array observations of the COSMOS field from the multi-band COSMOS-XS survey to infer radio luminosity functions (LFs) of star-forming galaxies (SFGs). Using $\sim$1300 SFGs with redshifts out to $z\sim4.6$, and fixing the faint and bright end shape of the radio LF to the local values, we find a strong redshift trend that can be fitted by pure luminosity evolution with the luminosity parameter given by $α_L \propto (3.40 \pm 0.11) - (0.48 \pm 0.06)z$. We then combine the ultra-deep COSMOS-XS data-set with the shallower VLA-COSMOS $\mathrm{3\,GHz}$ large project data-set over the wider COSMOS field in order to fit for joint density+luminosity evolution, finding evidence for significant density evolution. By comparing the radio LFs to the observed far-infrared (FIR) and ultraviolet (UV) LFs, we find evidence of a significant underestimation of the UV LF by $21.6\%\, \pm \, 14.3 \, \%$ at high redshift ($3.3\,<\,z\,<\,4.6$, integrated down to $0.03\,L^{\star}_{z=3}$). We derive the cosmic star formation rate density (SFRD) by integrating the fitted radio LFs and find that the SFRD rises up to $z\,\sim\,1.8$ and then declines more rapidly than previous radio-based estimates. A direct comparison between the radio SFRD and a recent UV-based SFRD, where we integrate both LFs down to a consistent limit ($0.038\,L^{\star}_{z=3}$), reveals that the discrepancy between the radio and UV LFs translates to a significant ($\sim$1 dex) discrepancy in the derived SFRD at $z>3$, even assuming the latest dust corrections and without accounting for optically dark sources.
