Examinando por Autor "Huang, J. S."

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Acceso Abierto
A Complete 16 μm Selected Galaxy Sample at z ∼ 1: Mid-infrared Spectral Energy Distributions
(IOP Science Publishing, 2021-05-28) Huang, J. S.; Dai, Y. S.; Willner, S. P.; Faber, S. M.; Cheng, C.; Xu, H.; Yan, H.; Wu, S.; Shao, X.; Hao, C.; Xia, X.; Rigopoulou, D.; Pereira Santaella, M.; Magdis, Georgios E.; Cortzen, I.; Fazio, G. G.; Assmann, P.; Fan, L.; Musin, M.; Zang, Z.; Xu, K. C.; He, C.; Jin, G.; Esamdin, A.; National Natural Science Foundation of China (NSFC); Chinese Academy of Sciences (CAS); Danish National Research Foundation (DNRF); Science and Technology Facilities Council (STFC); South America Center for Astronomy (CASSACA); Huang, J. S. [0000-0001-6511-8745]; Dai, Y. S. [0000-0002-7928-416X]; Willner, S. P. [0000-0002-9895-5758]; Faber, S. M. [0000-0003-4996-214X]; Cheng, C. [0000-0003-0202-0534]; Yan, H. [0000-0001-7592-7714]; Rigopoulou, D. [0000-0001-6854-7545]; Pereira Santaella, M. [0000-0002-4005-9619]; Magdis, G. [0000-0002-4872-2294]; Cortzen, I. [0000-0001-9197-7623]; Fazio, G. G. [0000-0002-0670-0708]; Fan, L. [0000-0003-4200-4432]; Jin, G. [0000-0003-3087-318X]; Esamdin, A. [0000-0003-1845-4900]
We describe a complete, flux-density-limited sample of galaxies at redshift 0.8 < z < 1.3 selected at 16 μm. At the selection wavelength near 8 μm rest, the observed emission comes from both dust heated by intense star formation and active galactic nuclei (AGNs). Fitting the spectral energy distributions (SEDs) of the sample galaxies to local-galaxy templates reveals that more than half the galaxies have SEDs dominated by star formation. About one-sixth of the galaxy SEDs are dominated by an AGN, and nearly all of the rest of the SEDs are composite. Comparison with X-ray and far-infrared observations shows that combinations of luminosities at rest-frame 4.5 and 8 μm give good measures of both AGN luminosity and star formation rate. The sample galaxies mostly follow the established star-forming main sequence for z = 1 galaxies, but of the galaxies more than 0.5 dex above that main sequence, more than half have AGN-type SEDs. Similarly, the most luminous AGNs tend to have higher star formation rates than the main-sequence value. Galaxies with stellar masses >1011 M⊙ are unlikely to host an AGN. About 1% of the sample galaxies show an SED with dust emission typical of neither star formation nor an AGN.
Acceso Abierto
Integral field spectroscopy of luminous infrared main-sequence galaxies at cosmic noon
(Oxford Academics: Oxford University Press, 2021-02-26) Hogan, L.; Rigopoulou, D.; Magdis, Georgios E.; Pereira Santaella, M.; García Bernete, I.; Thatte, N.; Grisdale, K.; Huang, J. S.; Science and Technology Facilities Council (STFC); Villum Fonden; Comunidad de Madrid; Magdis, G. E. [0000-0002-4872-2294]; Pereira Santaella, M. [0000-0002-4005-9619]; Grisdale, K. [0000-0003-0375-5997]
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 ∼ 2 dusty star-forming galaxies, uses the H α emission line to find that ∼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 α we detect [N II] 6583 Å 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.