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arXiv 2303.01658astro-ph.GAastro-ph.CO
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ALMA引力透镜星系团巡天:$z\simeq1-8$处的深场1.2毫米数计数与红外光度函数

ALMA Lensing Cluster Survey: Deep 1.2 mm Number Counts and Infrared Luminosity Functions at $z\simeq1-8$

Seiji Fujimoto, Kotaro Kohno, Masami Ouchi, Masamune Oguri, Vasily Kokorev, Gabriel Brammer, Fengwu Sun, Jorge Gonzalez-Lopez, Franz E. Bauer, Gabriel B. Caminh… 展开作者

Seiji Fujimoto, Kotaro Kohno, Masami Ouchi, Masamune Oguri, Vasily Kokorev, Gabriel Brammer, Fengwu Sun, Jorge Gonzalez-Lopez, Franz E. Bauer, Gabriel B. Caminha, Bunyo Hatsukade, Johan Richard, Ian Smail, Akiyoshi Tsujita, Yoshihiro Ueda, Ryosuke Uematsu, Adi Zitrin, Dan Coe, Jean-Paul Kneib, Marc Postman, Keiichi Umetsu, Claudia del P. Lagos, Gergo Popping, Yiping Ao, Larry Bradley, Karina Caputi, Miroslava Dessauges-Zavadsky, Eiichi Egami, Daniel Espada, R. J. Ivison, Mathilde Jauzac, Kirsten K. Knudsen, Anton M. Koekemoer, Georgios E. Magdis, Guillaume Mahler, A. M. Munoz Arancibia, Timothy Rawle, Kazuhiro Shimasaku, Sune Toft, Hideki Umehata, Francesco Valentino, Tao Wang, Wei-Halo Wang

AI总结:

本研究依托ALMA引力透镜星系团巡天,借助引力透镜放大效应探测极暗毫米波源,精准推导1.2毫米数计数与红移$z\simeq1-8$处的红外光度函数,揭示暗弱毫米波源贡献的额外恒星形成率密度组分,完善宇宙红外背景与恒星形成历史研究。

摘要:

我们依托ALMA引力透镜星系团巡天(ALCS),对在33个大质量星系团天区中识别出的180个尘埃连续谱源开展了统计研究,巡天总覆盖面积为133角分$^{2}$,所有观测均在1.2毫米波段均匀完成。ALCS借助引力透镜放大效应能够探测到极暗弱的毫米波源,其中包括在现有哈勃空间望远镜与斯皮策望远镜图像中均无对应体的近红外(NIR)暗天体。这些尘埃连续谱源分为两类:一类是信噪比$\gtrsim$5.0(纯度$>$0.99)的盲选样本($N=141$),另一类是通过先验信息筛选出的信噪比为$4.0-5.0$的次级样本($N=39$)。基于盲选样本,我们可靠地推导了低至$\sim7$$μ$Jy的1.2毫米数计数,发现1.2毫米总积分流量为20.7$^{+8.5}_{-6.5}$Jy每平方度$^{-2}$,解析了$\simeq$80%的宇宙红外背景光。由于毫米波辐射空间尺度相关的完备性校正存在差异,解析比例的变化幅度可达$0.6-1.1$倍。我们还采用$1/V_{\rm max}$方法推导了$z=0.6-7.5$处的红外(IR)光度函数(LFs),发现红外光度函数的红移演化表现为光度正演化、数密度负演化的特征。经估算,$z>4$处的宇宙总(紫外+红外)恒星形成率密度(SFRD)为既有测量值的$161^{+25}_{-21}$%,而既有测量几乎全部基于光学$-$近红外巡天。尽管我们对宇宙恒星形成率密度的整体认知不会出现超过2倍的偏差,但这些结果进一步佐证了由包括近红外暗天体在内的暗弱毫米波源族群贡献的额外($\approx 60$%)恒星形成率密度组分的存在。

英文摘要:

We present a statistical study of 180 dust continuum sources identified in 33 massive cluster fields by the ALMA Lensing Cluster Survey (ALCS) over a total of 133 arcmin$^{2}$ area, homogeneously observed at 1.2 mm. ALCS enables us to detect extremely faint mm sources by lensing magnification, including near-infrared (NIR) dark objects showing no counterparts in existing {\it Hubble Space Telescope} and {\it Spitzer} images. The dust continuum sources belong to a blind sample ($N=141$) with S/N $\gtrsim$ 5.0 (a purity of $>$ 0.99) or a secondary sample ($N=39$) with S/N= $4.0-5.0$ screened by priors. With the blind sample, we securely derive 1.2-mm number counts down to $\sim7$ $μ$Jy, and find that the total integrated 1.2mm flux is 20.7$^{+8.5}_{-6.5}$ Jy deg$^{-2}$, resolving $\simeq$ 80 % of the cosmic infrared background light. The resolved fraction varies by a factor of $0.6-1.1$ due to the completeness correction depending on the spatial size of the mm emission. We also derive infrared (IR) luminosity functions (LFs) at $z=0.6-7.5$ with the $1/V_{\rm max}$ method, finding the redshift evolution of IR LFs characterized by positive luminosity and negative density evolution. The total (=UV+IR) cosmic star-formation rate density (SFRD) at $z>4$ is estimated to be $161^{+25}_{-21}$ % of the established measurements, which were almost exclusively based on optical$-$NIR surveys. Although our general understanding of the cosmic SFRD is unlikely to change beyond a factor of 2, these results add to the weight of evidence for an additional ($\approx 60$ %) SFRD component contributed by the faint-mm population, including NIR dark objects.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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