论文标题
$ z \ sim 2 $的系统搜索Galaxy Proto-Cluster内核
A Systematic Search for Galaxy Proto-Cluster Cores at $z\sim 2$
论文作者
论文摘要
在给定的原始群集中，原始群集芯是最大的暗物质光环（DMH）。为了揭示核心区域中的星系组，我们在$ \ sim 1.5 \，\ mathrm {deg}^{2} $的proto-cluster内核中搜索$ z \ sim 2 $ in $ \ sim 2 $。使用一对大型星系（$ \ log（M _ {*}/M _ {\ odot}）\ GEQ11 $）作为内核的示踪剂，我们发现75个候选核心，其中54％\％估计是真实的。聚类分析发现，这些内核的平均DMH质量为$ 2.6 _ { - 0.8}^{+0.9} \ times 10^{13} \，m _ {\ odot} $，或$ 4.0 _ { - 1.5}^{ - 1.5}^{+1.8}^{+1.8} \，\，\，\，\，\，\ \ \ \ time 10^firtam time 10^form and}。扩展的新闻编组模型表明，它们的后代质量在$ z = 0 $上与类似Fornax的或类似处女的簇一致。此外，使用Illustristng模拟，我们确认对大型星系对的良好示踪剂是巨大的大量示踪剂，足以被视为原始群集核心。然后，我们得出75个候选核心的成员星系的恒星质量函数（SMF）和静态分数。我们发现，核心星系比同一红移的现场星系具有更高的SMF，显示了$ \ log（m _ {*}/m _ {\ odot}）\ gtrsim 10.5 $的多余。 The quiescent fraction, $0.17_{-0.04}^{+0.04}$ in the mass range $9.0\leq \log(M_{*}/M_{\odot})\leq 11.0$, is about three times higher than that of field counterparts, giving an environmental quenching efficiency of $ 0.13 _ { - 0.04}^{+0.04} $。这些结果表明，恒星质量组装和淬火早在$ z \ sim 2 $ in Proto-Cluster核心的加速。
A proto-cluster core is the most massive dark matter halo (DMH) in a given proto-cluster. To reveal the galaxy formation in core regions, we search for proto-cluster cores at $z\sim 2$ in $\sim 1.5\, \mathrm{deg}^{2}$ of the COSMOS field. Using pairs of massive galaxies ($\log(M_{*}/M_{\odot})\geq11$) as tracers of cores, we find 75 candidate cores, among which 54\% are estimated to be real. A clustering analysis finds that these cores have an average DMH mass of $2.6_{-0.8}^{+0.9}\times 10^{13}\, M_{\odot}$, or $4.0_{-1.5}^{+1.8}\, \times 10^{13} M_{\odot}$ after contamination correction. The extended Press-Schechter model shows that their descendant mass at $z=0$ is consistent with Fornax-like or Virgo-like clusters. Moreover, using the IllustrisTNG simulation, we confirm that pairs of massive galaxies are good tracers of DMHs massive enough to be regarded as proto-cluster cores. We then derive the stellar mass function (SMF) and the quiescent fraction for member galaxies of the 75 candidate cores. We find that the core galaxies have a more top-heavy SMF than field galaxies at the same redshift, showing an excess at $\log(M_{*}/M_{\odot})\gtrsim 10.5$. The quiescent fraction, $0.17_{-0.04}^{+0.04}$ in the mass range $9.0\leq \log(M_{*}/M_{\odot})\leq 11.0$, is about three times higher than that of field counterparts, giving an environmental quenching efficiency of $0.13_{-0.04}^{+0.04}$. These results suggest that stellar mass assembly and quenching are accelerated as early as at $z\sim 2$ in proto-cluster cores.
