TY - JOUR

T1 - ALMA Lensing Cluster Survey

T2 - A spectral stacking analysis of [C II] in lensed z similar to 6 galaxies

AU - Jolly, Jean-Baptiste

AU - Knudsen, Kirsten

AU - Laporte, Nicolas

AU - Richard, Johan

AU - Fujimoto, Seiji

AU - Kohno, Kotaro

AU - Ao, Yiping

AU - Bauer, Franz E.

AU - Egami, Eiichi

AU - Espada, Daniel

AU - Dessauges-Zavadsky, Miroslava

AU - Magdis, Georgios

AU - Schaerer, Daniel

AU - Sun, Fengwu

AU - Valentino, Francesco

AU - Wang, Wei-Hao

AU - Zitrin, Adi

PY - 2021/8/23

Y1 - 2021/8/23

N2 - Context. 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 mu m 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 > 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 (sigma(z)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.

AB - Context. 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 mu m 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 > 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 (sigma(z)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.

KW - galaxies: formation

KW - galaxies: statistics

KW - galaxies: high-redshift

KW - radio lines: galaxies

KW - galaxies: evolution galaxies: star formation

KW - STAR-FORMING GALAXIES

KW - ULTRA-DEEP FIELD

KW - REST-FRAME PROPERTIES

KW - LYMAN-BREAK GALAXIES

KW - LY-ALPHA-EMITTERS

KW - MU-M EMISSION

KW - FRONTIER-FIELDS

KW - COSMIC REIONIZATION

KW - MOLECULAR GAS

KW - MULTIWAVELENGTH PHOTOMETRY

U2 - 10.1051/0004-6361/202140878

DO - 10.1051/0004-6361/202140878

M3 - Journal article

VL - 652

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A128

ER -