In:
The Astrophysical Journal, American Astronomical Society, Vol. 911, No. 2 ( 2021-04-01), p. 99-
Abstract:
We present bright [C ii ] 158 μ m line detections from a strongly magnified and multiply imaged ( μ ∼ 20–160) sub– L * ( M UV = − 19.75 − 0.44 + 0.55 ) Lyman-break galaxy (LBG) at z = 6.0719 ± 0.0004, drawn from the ALMA Lensing Cluster Survey (ALCS). Emission lines are identified at 268.7 GHz at ≥8 σ exactly at the 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 (∼6″) arc with a local magnification of μ ∼ 160, for which the [C ii ] line is also significantly detected. The source plane reconstruction resolves the interstellar medium (ISM) structure, showing that the [C ii ] line is co-spatial with the rest-frame UV continuum at a scale of ∼300 pc. The [C ii ] line properties suggest that the LBG is a rotation-dominated system, whose velocity gradient explains a slight difference in redshifts between the whole LBG and its sub-region. The star formation rate (SFR)– L [CII] relations, for whole and sub-regions of the LBG, are consistent with those of local galaxies. We evaluate the lower limit of the faint-end of the [C ii ] luminosity function at z = 6, finding it to be consistent with predictions from semi-analytical models and from the local SFR– L [CII] relation with a SFR function at z = 6. These results imply that the local SFR– L [CII] relation is universal for a wide range of scales, including the spatially resolved ISM, the whole region of the galaxy, and the cosmic scale, even in the epoch of reionization.
Type of Medium:
Online Resource
ISSN:
0004-637X
,
1538-4357
DOI:
10.3847/1538-4357/abd7ec
Language:
Unknown
Publisher:
American Astronomical Society
Publication Date:
2021
detail.hit.zdb_id:
2207648-7
detail.hit.zdb_id:
1473835-1
SSG:
16,12
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