A kpc-scale resolved study of unobscured and obscured star-formation activity in normal galaxies at z = 1.5 and 2.2 from ALMA and HiZELS

Abstract

We present Atacama Large Millimeter/Submillimeter Array (ALMA) continuum observations of a sample of nine star-forming galaxies at redshifts 1.47 and 2.23 selected from the High-$z$ Emission Line Survey (HiZELS). Four galaxies in our sample are detected at high significance by ALMA at a resolution of 0.25'' at rest-frame 355 $\mu$m. Together with the previously observed H$\alpha$ emission, from adaptive optics-assisted integral-field-unit spectroscopy (0.15'' resolution), and F606W and F140W imaging from the Hubble Space Telescope (0.2'' resolution), we study the star-formation activity, stellar and dust mass in these high-redshift galaxies at $\sim$kpc-scale resolution. We find that ALMA detection rates are higher for more massive galaxies ($M_{\ast }>10^{10.5}$ M${}_{\odot }$) and higher [N {\sc ii}]/H$\alpha$ ratios ($>0.25$, a proxy for gas-phase metallicity). The dust extends out to a radius of 8 kpc, with a smooth structure, even for those galaxies presenting clumpy H$\alpha$ morphologies. The half-light radii ($R_{\mathrm{dust}}$) derived for the detected galaxies are of the order $\sim$4.5 kpc, more than twice the size of submillimetre-selected galaxies at a similar redshift. Our global star-formation rate estimates -- from far-IR and extinction-corrected H$\alpha$ luminosities -- are in good agreement. However, the different morphologies of the different phases of the interstellar medium suggest complex extinction properties of the high-redshift normal galaxies.

13 pages, 7 figures, MNRAS accepted

References in corpus (31)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Cosmic Evolution Survey (COSMOS) -- Overview
• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• The Mass-Metallicity Relation at z~2
• From rings to bulges: evidence for rapid secular galaxy evolution at z~2 from integral field spectroscopy in the SINS survey
• The rapid formation a large rotating disk galaxy three billion years after the Big Bang
• An Ultraviolet-to-Radio Broadband Spectral Atlas of Nearby Galaxies
• 350 Micron Dust Emission from High Redshift Quasars
• Kiloparsec-scale dust disks in high-redshift luminous submillimeter galaxies
• New fully empirical calibrations of strong-line metallicity indicators in star forming galaxies
• Kinemetry of SINS High-Redshift Star-Forming Galaxies: Distinguishing Rotating Disks from Major Mergers
• Nebular Emission Line Ratios in z~2-3 Star-Forming Galaxies with KBSS-MOSFIRE: Exploring the Impact of Ionization, Excitation, and Nitrogen-to-Oxygen Ratio
• The SCUBA-2 Cosmology Legacy Survey: ALMA resolves the rest-frame far-infrared emission of sub-millimeter galaxies
• Radio imaging of the Subaru/XMM-Newton Deep Field - I. The 100-microJy catalogue, optical identifications, and the nature of the faint radio source population
• HiZELS: a high redshift survey of H-alpha emitters. I: the cosmic star-formation rate and clustering at z=2.23
• The Subaru/XMM-Newton Deep Survey (SXDS): III. X-Ray Data
• Half-mass radii for ~7,000 galaxies at 1.0 < z < 2.5: most of the evolution in the mass-size relation is due to color gradients
• VLA and ALMA Imaging of Intense, Galaxy-Wide Star Formation in z ~ 2 Galaxies
• Bulge-forming galaxies with an extended rotating disk at z~2
• An ALMA survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS field: High-resolution dust continuum morphologies and the link between sub-millimetre galaxies and spheroid formation
• The dust-to-stellar mass ratio as a valuable tool to probe the evolution of local and distant star forming galaxies
• Structural evolution in massive galaxies at z~2
• The evolution of the star formation rate function in the EAGLE simulations: A comparison with UV, IR and H$\alpha$ observations from z ~ 8 to z ~ 0
• The ISM scaling relations in DustPedia late-type galaxies: A benchmark study for the Local Universe
• Revealing the Stellar Mass and Dust Distributions of Submillimeter Galaxies at Redshift 2
• SINFONI-HiZELS: The dynamics, merger rates & metallicity gradients of `typical' star-forming galaxies at $z$ = 0.8-2.2
• The structural and size evolution of star-forming galaxies over the last 11 Gyrs
• The kiloparsec-scale gas kinematics in two star-forming galaxies at $z\sim 1.47$ seen with ALMA and VLT-SINFONI
• The Dynamics and Distribution of Angular Momentum in HiZELS Star-Forming Galaxies at z = 0.8 - 3.3
• UV and NIR size of the low-mass field galaxies: the UV compact galaxies
• Low-redshift analogs of submm galaxies: a diverse population

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