Journal article · Preprint article
ALMA Lensing Cluster Survey: A spectral stacking analysis of [C II] in lensed z ∼ 6 galaxies
Chalmers University of Technology1
Université de Genève2
National Space Institute, Technical University of Denmark3
Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark4
Academia Sinica Taiwan5
Ben-Gurion University of the Negev6
University of Cambridge7
Université de Lyon8
University of Copenhagen9
The University of Tokyo10
Chinese Academy of Sciences11
Pontificia Universidad Católica de Chile12
University of Arizona13
SKA Organisation14
...and 4 moreContext. The properties of galaxies at redshift z > 6 hold the key to our understanding of the early stages of galaxy evolution and can potentially identify the sources of the ultraviolet radiation that give rise to the epoch of reionisation. The far-infrared cooling line of [C II] at 158 μm is known to be bright and correlate with the star formation rate (SFR) of low-redshift galaxies, and hence is also suggested to be an important tracer of star formation and interstellar medium properties for very high-redshift galaxies.
Aims. With the aim to study the interstellar medium properties of gravitationally lensed galaxies at z > 6, we search for [C II] and thermal dust emission in a sample of 52 z ∼ 6 galaxies observed by the ALMA Lensing Cluster Survey. Methods. We perform our analysis using LINESTACKER, stacking both [C II] and continuum emission.
The target sample is selected from multiple catalogues, and the sample galaxies have spectroscopic redshift or low-uncertainty photometric redshifts (σz < 0.02) in nine galaxy clusters. Source properties of the target galaxies are either extracted from the literature or computed using spectral energy distribution fitting.
Both weighted-average and median stacking are used, on both the full sample and three sub-samples. Results. Our analyses find no detection of either [C II] or continuum. An upper limit on L[CII] is derived, implying that [C II] remains marginally consistent for low-SFR z > 6 galaxies but likely is under-luminous compared to the local L[CII]-SFR relationship.
We discuss potential biases and possible physical effects that may be the cause of the non-detection. Further, the upper limit on the dust continuum implies that less than half of the star formation is obscured.
Language: | English |
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Publisher: | EDP Sciences |
Year: | 2021 |
Pages: | A128 |
ISSN: | 14320746 and 00046361 |
Types: | Journal article and Preprint article |
DOI: | 10.1051/0004-6361/202140878 |
ORCIDs: | 0000-0001-7201-5066 , Magdis, Georgios , 0000-0001-6477-4011 , 0000-0002-3405-5646 , 0000-0002-7821-8873 , 0000-0001-7459-6335 , 0000-0001-5492-1049 , 0000-0002-4052-2394 , 0000-0003-3139-2724 , 0000-0002-8686-8737 , 0000-0002-8726-7685 , 0000-0003-0348-2917 , 0000-0001-7144-7182 , 0000-0002-4622-6617 and 0000-0002-0350-4488 |
Galaxies: evolution Galaxies: formation Galaxies: high-redshift Galaxies: statistics Radio lines: galaxies
COSMIC REIONIZATION FRONTIER-FIELDS LY-ALPHA-EMITTERS LYMAN-BREAK GALAXIES MOLECULAR GAS MU-M EMISSION MULTIWAVELENGTH PHOTOMETRY REST-FRAME PROPERTIES STAR-FORMING GALAXIES ULTRA-DEEP FIELD astro-ph.GA galaxies: evolution galaxies: star formation galaxies: formation galaxies: high-redshift galaxies: statistics radio lines: galaxies