ALMA Lensing Cluster Survey: Bright [CII] 158 $��$m Lines from a Multiply Imaged Sub-$L^{\star}$ Galaxy at $z=6.0719$
Autor: | Fujimoto, Seiji, Oguri, Masamune, Brammer, Gabriel, Yoshimura, Yuki, Laporte, Nicolas, Gonz��lez-L��pez, Jorge, Caminha, Gabriel B., Kohno, Kotaro, Zitrin, Adi, Richard, Johan, Ouchi, Masami, Bauer, Franz E., Smail, Ian, Hatsukade, Bunyo, Ono, Yoshiaki, Kokorev, Vasily, Umehata, Hideki, Schaerer, Daniel, Knudsen, Kirsten, Sun, Fengwu, Magdis, Georgios, Valentino, Francesco, Ao, Yiping, Toft, Sune, Dessauges-Zavadsky, Miroslava, Shimasaku, Kazuhiro, Caputi, Karina, Kusakabe, Haruka, Morokuma-Matsui, Kana, Shotaro, Kikuchihara, Egami, Eiichi, Lee, Minju M., Rawle, Timothy, Espada, Daniel |
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Rok vydání: | 2021 |
Předmět: | |
DOI: | 10.48550/arxiv.2101.01937 |
Popis: | We present bright [CII] 158 $��$m line detections from a strongly magnified and multiply-imaged ($��\sim20-160$) sub-$L^{*}$ ($M_{\rm UV}$ = $-19.75^{+0.55}_{-0.44}$) Lyman-break galaxy (LBG) at $z=6.0719\pm0.0004$ from the ALMA Lensing Cluster Survey (ALCS). Emission lines are identified at 268.7 GHz at $\geq$ 8$��$ exactly at positions of two multiple images of the LBG behind the massive galaxy cluster RXCJ0600$-$2007. Our lens models, updated with the latest spectroscopy from VLT/MUSE, indicate that a sub region of the LBG crosses the caustic and is lensed into a long ($\sim6''$) arc with a local magnification of $��\sim 160$, for which the [CII] line is also significantly detected. The source-plane reconstruction resolves the interstellar medium (ISM) structure, showing that the [CII] line is co-spatial with the rest-frame UV continuum at the scale of $\sim$300 pc. The [CII] line properties suggest that the LBG is a rotation-dominated system whose velocity gradient explains a slight difference of redshifts between the whole LBG and its sub region. The star formation rate (SFR)-$L_{\rm [CII]}$ relations from the sub to the whole regions of the LBG are consistent with those of local galaxies. We evaluate the lower limit of the faint-end of the [CII] luminosity function at $z=6$, and find that it is consistent with predictions from semi analytical models and from the local SFR-$L_{\rm [CII]}$ relation with a SFR function at $z=6$. These results imply that the local SFR-$L_{\rm [CII]}$ relation is universal for a wide range of scales including the spatially resolved ISM, the whole region of galaxy, and the cosmic scale, even in the epoch of reionization. 27 pages, 10 figures, 6 tables, ApJ in press |
Databáze: | OpenAIRE |
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