TY - JOUR

T1 - Integral field spectroscopy of luminous infrared main-sequence galaxies at cosmic noon

AU - Hogan, L.

AU - Rigopoulou, D.

AU - Magdis, G. E.

AU - Pereira-Santaella, M.

AU - Garcia-Bernete, I

AU - Thatte, N.

AU - Grisdale, K.

AU - Huang, J. S.

PY - 2021/6/2

Y1 - 2021/6/2

N2 - We present the results of an integral field spectroscopy survey of a sample of dusty (ultra) luminous infrared galaxies (U/LIRGs) at 2 < z < 2.5 using KMOS on the Very Large Telescope. The sample has been drawn from Herschel deep field surveys and benefits from ancillary multiwavelength data. Our goal is to investigate the physical characteristics, kinematics, and the drivers of star formation in the galaxies whose contribution dominates the peak of the cosmic star formation density. Two-thirds of the sample are main-sequence galaxies in contrast to the starburst nature of local U/LIRGs. Our kinematic study, unique in its focus on z similar to 2 dusty star-forming galaxies, uses the H alpha emission line to find that similar to 40 per cent appear to be isolated discs based on the ratio of rotational velocity to the velocity dispersion, suggesting steady-state mechanisms are sufficient to power the large star formation rates (SFRs). The ratio of obscured to unobscured star formation indicates the sample of galaxies experiences less dust obscuration compared to intermediate and local counterparts, while also hosting cooler dust than local U/LIRGs. In addition to H alpha we detect [N II] 6583 angstrom in our targets and show the gas-phase metallicities do not exhibit the metal deficiency of local U/LIRGs. These results indicate that, despite their extreme IR luminosity, the underlying mechanisms driving the massive SFRs found at cosmic noon are due to scaled up disc galaxies as opposed to mergers.

AB - We present the results of an integral field spectroscopy survey of a sample of dusty (ultra) luminous infrared galaxies (U/LIRGs) at 2 < z < 2.5 using KMOS on the Very Large Telescope. The sample has been drawn from Herschel deep field surveys and benefits from ancillary multiwavelength data. Our goal is to investigate the physical characteristics, kinematics, and the drivers of star formation in the galaxies whose contribution dominates the peak of the cosmic star formation density. Two-thirds of the sample are main-sequence galaxies in contrast to the starburst nature of local U/LIRGs. Our kinematic study, unique in its focus on z similar to 2 dusty star-forming galaxies, uses the H alpha emission line to find that similar to 40 per cent appear to be isolated discs based on the ratio of rotational velocity to the velocity dispersion, suggesting steady-state mechanisms are sufficient to power the large star formation rates (SFRs). The ratio of obscured to unobscured star formation indicates the sample of galaxies experiences less dust obscuration compared to intermediate and local counterparts, while also hosting cooler dust than local U/LIRGs. In addition to H alpha we detect [N II] 6583 angstrom in our targets and show the gas-phase metallicities do not exhibit the metal deficiency of local U/LIRGs. These results indicate that, despite their extreme IR luminosity, the underlying mechanisms driving the massive SFRs found at cosmic noon are due to scaled up disc galaxies as opposed to mergers.

KW - ISM: kinematics and dynamics

KW - infrared: galaxies

KW - infrared: ISM

KW - galaxies: ISM

KW - STAR-FORMING GALAXIES

KW - SPECTRAL ENERGY-DISTRIBUTIONS

KW - SIMILAR-TO 1-3

KW - MOLECULAR GAS

KW - SCALING RELATIONS

KW - MASSIVE GALAXIES

KW - SUBMILLIMETER GALAXIES

KW - INTERSTELLAR-MEDIUM

KW - ALMA OBSERVATIONS

KW - DEPLETION TIME

U2 - 10.1093/mnras/stab527

DO - 10.1093/mnras/stab527

M3 - Journal article

VL - 503

SP - 5329

EP - 5350

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

SN - 0035-8711

IS - 4

ER -