%0 Journal Article
%T CO, H2O, H2O+ line and dust emission in a z = 3.63 strongly lensed starburst merger at sub-kiloparsec scales
%A A. Beelen
%A A. Cooray
%A A. M. Swinbank
%A A. Omont
%A C. Yang
%A D. A. Riechers
%A E. Gonz¨¢lez-Alfonso
%A E. Ibar
%A H. Fu
%A H. Nayyeri
%A I. P¨¦rez-Fournon
%A I. Smail
%A J. Nightingale
%A L. Barcos-Mu£¿oz
%A M. D. Lehnert
%A M. J. Micha£¿owski
%A M. Negrello
%A P. Cox
%A P. van der Werf
%A R. Gavazzi
%A R. J. Ivison
%A R. Neri
%A S. Dye
%A S. Eales
%A Y. Gao
%J -
%D 2019
%R 10.1051/0004-6361/201833876
%X Using the Atacama Large Millimeter/submillimeter Array (ALMA), we report high angular-resolution observations of the redshift <i>z<i/>£¿£¿=£¿3.63 galaxy <i>H<i/>-ATLAS J083051.0+013224 (G09v1.97), one of the most luminous strongly lensed galaxies discovered by the <i>Herschel<i/>-Astrophysical Terahertz Large Area Survey (<i>H<i/>-ATLAS). We present resolution images of the rest-frame 188 and 419£¿<i>¦Ì<i/>m dust continuum and the CO(6¨C5), H<sub>2<sub/>O(2<sub>11<sub/>£¿2<sub>02<sub/>), and <i>J<i/><sub>up<sub/>£¿=£¿2£¿H<sub>2<sub/>O<sup>+<sup/> line emission. We also report the detection of H<sub>2<sub/>O(2<sub>11<sub/>£¿2<sub>02<sub/>) in this source. The dust continuum and molecular gas emission are resolved into a nearly complete diameter Einstein ring plus a weaker image in the center, which is caused by a special dual deflector lensing configuration. The observed line profiles of the CO(6¨C5), H<sub>2<sub/>O(2<sub>11<sub/>£¿2<sub>02<sub/>), and <i>J<i/><sub>up<sub/>£¿=£¿2£¿H<sub>2<sub/>O<sup>+<sup/> lines are strikingly similar. In the source plane, we reconstruct the dust continuum images and the spectral cubes of the CO, H<sub>2<sub/>O, and H<sub>2<sub/>O<sup>+<sup/> line emission at sub-kiloparsec scales. The reconstructed dust emission in the source plane is dominated by a compact disk with an effective radius of 0.7£¿¡À£¿0.1 kpc plus an overlapping extended disk with a radius twice as large. While the average magnification for the dust continuum is <i>¦Ì<i/>£¿¡«£¿10£¿11, the magnification of the line emission varies from 5 to 22 across different velocity components. The line emission of CO(6¨C5), H<sub>2<sub/>O(2<sub>11<sub/>£¿2<sub>02<sub/>), and H<sub>2<sub/>O<sup>+<sup/> have similar spatial and kinematic distributions. The molecular gas and dust content reveal that G09v1.97 is a gas-rich major merger in its pre-coalescence phase, with a total molecular gas mass of ¡«10<sup>11<sup/>£¿<i>M<i/><sub>¡Ñ<sub/>. Both of the merging companions are intrinsically ultra-luminous infrared galaxies (ULIRGs) with infrared luminosities <i>L<i/><sub>IR<sub/> reaching £¿4£¿¡Á£¿10<sup>12<sup/>£¿<i>L<i/><sub>¡Ñ<sub/>, and the total <i>L<i/><sub>IR<sub/> of G09v1.97 is (1.4£¿¡À£¿0.7)¡Á10<sup>13<sup/>£¿<i>L<i/><sub>¡Ñ<sub/>. The approaching southern galaxy (dominating from <i>V<i/>£¿=£¿£¿400 to £¿150 km s<sup>£¿1<sup/> relative to the systemic velocity) shows no obvious kinematic structure with a semi-major half-light radius of <i>a<i/><sub>s<sub/>£¿=£¿0.4 kpc, while the receding galaxy (0 to 350 km s<sup>£¿1<sup/>) resembles an <i>a<i/><sub>s<sub/>£¿=£¿1.2 kpc rotating disk. The two galaxies are separated
%U https://www.aanda.org/articles/aa/full_html/2019/04/aa33876-18/aa33876-18.html