论文标题
强度映射检测在3 mm处的聚集物CO线发射
An Intensity Mapping Detection of Aggregate CO Line Emission at 3 mm
论文作者
论文摘要
我们使用线强度映射技术对$ z \ sim1-5 $的分子气体发射进行检测。我们利用一对3 mm的干涉数据集，这是哈勃超深田（ASPEC）中ALMA光谱调查的第一项，第二个来自2016年至2018年之间进行的一系列Atacama紧凑型阵列（ACA）观察结果，以宇宙为目标。在100 GHz时，我们分别在ACA和ALMA数据集的97.8％和99.9％的信心下测量非零功率。在联合结果中，我们以99.99％的信心拒绝了零功率假设，发现$ \ tilde {i}^{2} _ {s} _ {s}（v）= 770 \ pm210 \μ\μ\ textrm {k}^2 \ \ \ \ \ \ \ \ \ \ \ \ \\ textrm {在考虑了样本方差效应之后，估计的频谱射击功率为$ \ tilde {i}^{2} _ {s}（ν）= 1010 _ { - 390}^{+550} \μ\μ\ textrm {k}^2 \ \ \ \ \ \ \ \ \ \ \ \ \ textrm {我们得出了各种物种的模型，预计我们的测量值将对$ 120 _ { - 40}^{+80} \μ\ textrm {k}^2 \ h^2 \ h^{ - 3} \，3} \，\ textrm {mpc}^$ {3} $，{3} $，{3} $，{3} $，{3}^{ μ\ textrm {k}^2 \ h^{ - 3} \，\ textrm {mpc}^{3} $和$ 90^{+70} _ { - 40} \μ\μ\μ\ textrm {k} $ z = 1.3 $，co（3-2）$ z = 2.5 $和$ z = 3.6 $的CO（2-1）。使用适合高红移星系的线比，我们发现这些结果与CO功率谱调查（COPSS）的线比非常吻合。采用$α_ {\ rm co} = 3.6 \ m _ {\ odot} \（\ textrm {k} \ \ \ \ \ \\ textrm {km} \ \ \ \ \ \\ textrm {s}}^{ - 1}^{ - 1} $ρ_{\ textrm {h} _2}（z）\ sim 10^{8} \ m _ {\ odot} \ \ \ \ textrm {mpc}^{ - 3} $ of $ρ_ {\ textrm {h} _2}（z）
We present a detection of molecular gas emission at $z\sim1-5$ using the technique of line intensity mapping. We make use of a pair of 3 mm interferometric data sets, the first from the ALMA Spectroscopic Survey in the Hubble Ultra Deep Field (ASPECS), and the second from a series of Atacama Compact Array (ACA) observations conducted between 2016 and 2018, targeting the COSMOS field. At 100 GHz, we measure non-zero power at 97.8% and 99.9% confidence in the ACA and ALMA data sets, respectively. In the joint result, we reject the zero-power hypothesis at 99.99% confidence, finding $\tilde{I}^{2}_{s}(ν)=770\pm210\ μ\textrm{K}^2\ \textrm{Hz}\ \textrm{sr}$. After accounting for sample variance effects, the estimated spectral shot power is $\tilde{I}^{2}_{s}(ν)=1010_{-390}^{+550}\ μ\textrm{K}^2\ \textrm{Hz}\ \textrm{sr}$. We derive a model for the various line species our measurement is expected to be sensitive to, and estimate the shot power to be $120_{-40}^{+80}\ μ\textrm{K}^2\ h^{-3}\,\textrm{Mpc}^{3}$, $200^{+120}_{-70}\ μ\textrm{K}^2\ h^{-3}\,\textrm{Mpc}^{3}$, and $90^{+70}_{-40}\ μ\textrm{K}^2\ h^{-3}\,\textrm{Mpc}^{3}$ for CO(2-1) at $z=1.3$, CO(3-2) at $z=2.5$, and CO(4-3) at $z=3.6$, respectively. Using line ratios appropriate for high-redshift galaxies, we find these results to be in good agreement with those from the CO Power Spectrum Survey (COPSS). Adopting $α_{\rm CO}=3.6\ M_{\odot}\ (\textrm{K}\ \textrm{km}\ \textrm{s}^{-1}\ \textrm{pc}^{2})^{-1}$, we estimate a cosmic molecular gas density of $ρ_{\textrm{H}_2}(z)\sim 10^{8}\ M_{\odot}\ \textrm{Mpc}^{-3}$ between $z=1-3$.
