Radial profiles of lensed $z\sim 1$ galaxies on sub-kiloparsec scales

Abstract

We study the spatially resolved physical properties of the Cosmic Snake arc in MACS J1206.2-0847 and the arc in Abell 0521 (A521). These are two strongly lensed galaxies at redshifts $z=1.036$ and $z=1.044$. We used observations of the Hubble Space Telescope (HST) and the Atacama Large Millimeter/submillimeter Array (ALMA). The former gives access to the star formation rate (SFR) and stellar mass ($M_{\star }$), and the latter to the H${}_2$ molecular gas mass ($M_{\mathrm{mol}}$). HST and ALMA observations have similar angular resolutions of $0.15^{\prime \prime }-0.2^{\prime \prime }$, which with the help of strong gravitational lensing enable us to reach spatial resolutions down to $\sim 30\mathrm{pc}$ and $\sim 100\mathrm{pc}$ in these two galaxies, respectively. These resolutions are close to the resolution of observations of nearby galaxies. We study the radial profiles of SFR, $M_{\star }$, and $M_{\mathrm{mol}}$ surface densities of these high-redshift galaxies and compare the corresponding exponential scale lengths with those of local galaxies. We find that the scale lengths in the Cosmic Snake are about $0.5\mathrm{kpc}-1.5\mathrm{kpc}$, and they are 3 to 10 times larger in A521. This is a significant difference knowing that the two galaxies have comparable integrated properties. These high-redshift scale lengths are nevertheless comparable to those of local galaxies, which cover a wide distribution. The particularity of our high-redshift radial profiles is the normalisation of the $M_{\mathrm{mol}}$ surface density profiles ($\Sigma M_{\mathrm{mol}}$), which are offset by up to a factor of 20 with respect to the profiles of $z=0$ counterparts. The SFR surface density profiles are also offset by the same factor as $\Sigma M_{\mathrm{mol}}$, as expected from the Kennicutt-Schmidt law.

15 pages, 10 figures, accepted for publication in A&A

References in corpus (16)

• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample
• A Bayesian approach to strong lensing modelling of galaxy clusters
• Dust Formation and Survival in Supernova Ejecta
• 350 Micron Dust Emission from High Redshift Quasars
• Evidence for Mature Bulges and an Inside-out Quenching Phase 3 Billion Years After the Big Bang
• CO excitation of normal star forming galaxies out to z=1.5 as regulated by the properties of their interstellar medium
• A method to remove residual OH emission from near infrared spectra
• Resolved spectroscopy of gravitationally lensed galaxies: global dynamics and star-forming clumps on ~100pc scales
• The nature of giant clumps in distant galaxies probed by the anatomy of the Cosmic Snake
• Geometrically Derived Timescales for Star Formation in Spiral Galaxies
• The MUSE Atlas of Disks (MAD): Resolving Star Formation Rates and Gas Metallicities on < 100pc Scales
• Spatially resolved properties of galaxies from CANDELS+MUSE: Radial extinction profile and insights on quenching
• Internal structure of molecular gas in a main sequence galaxy with a UV clump at z = 1.45
• Probing Individual Star Forming Regions Within Strongly Lensed Galaxies at z > 1

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