TY - JOUR

T1 - A Large-scale Kinematic Study of Molecular Gas in High-z Cluster Galaxies

T2 - Evidence for High Levels of Kinematic Asymmetry

AU - Cramer, W. J.

AU - Noble, A. G.

AU - Massingill, K.

AU - Cairns, J.

AU - Clements, D. L.

AU - Cooper, M. C.

AU - Demarco, R.

AU - Matharu, J.

AU - McDonald, M.

AU - Muzzin, A.

AU - Nantais, J.

AU - Rudnick, G.

AU - uebler, H.

AU - van Kampen, E.

AU - Webb, T. M. A.

AU - Wilson, G.

AU - Yee, H. K. C.

PY - 2023/2/1

Y1 - 2023/2/1

N2 - We investigate the resolved kinematics of the molecular gas, as traced by the Atacama Large Millimeter/submillimeter Array in CO (2-1), of 25 cluster member galaxies across three different clusters at a redshift of z similar to 1.6. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding sides of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift based on observations of mainly ionized gas. However, this leaves 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to similar to 50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low redshift, is also active in the high-redshift universe.

AB - We investigate the resolved kinematics of the molecular gas, as traced by the Atacama Large Millimeter/submillimeter Array in CO (2-1), of 25 cluster member galaxies across three different clusters at a redshift of z similar to 1.6. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding sides of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift based on observations of mainly ionized gas. However, this leaves 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to similar to 50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low redshift, is also active in the high-redshift universe.

KW - STAR-FORMING GALAXIES

KW - PRESSURE STRIPPED TAIL

KW - DARK-MATTER FRACTIONS

KW - SIMILAR-TO 2.6

KW - RAM-PRESSURE

KW - ROTATION CURVES

KW - SPECTROSCOPIC CONFIRMATION

KW - QUENCHING EFFICIENCY

KW - FUNDAMENTAL PLANE

KW - MASSIVE GALAXIES

U2 - 10.3847/1538-4357/acae96

DO - 10.3847/1538-4357/acae96

M3 - Journal article

VL - 944

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 213

ER -