The Atacama Cosmology Telescope: CO(J = 3 – 2) Mapping and Lens Modeling of an ACT-selected Dusty Star-forming Galaxy

We report Northern Extended Millimeter Array CO(J = 3 - 2) observations of the dusty star-forming galaxy ACT-S J020941+001557 at z = 2.5528, which was detected as an unresolved source in the Atacama Cosmology Telescope (ACT) equatorial survey. Our spatially resolved spectral line data support the derivation of a gravitational lens model from 37 independent velocity channel maps using a pixel-based algorithm, from which we infer a velocity-dependent magnification factor mu approximate to 7-22 with a luminosity-weighted mean approximate to 13. The resulting source-plane reconstruction is consistent with a rotating disk, although other scenarios cannot be ruled out by our data. After correction for lensing, we derive a line luminosity LCO(3-2)' = (5.53 +/- 0.69) x 10(10) K km s(-1) pc(2), a cold gas mass M-gas = (3.86 +/- 0.33) x 10(10) M-circle dot, a dynamical mass M-dyn sin(2) i = 3.9(-1.5)(+1.8) x 10(10) M-circle dot, and a gas mass fraction f(gas) csc(2) i = 1.0(-0.4)(+0.8). The line brightness temperature ratio of r(3,1) approximate to 1.6 relative to a Green Bank Telescope CO(J = 1 - 0) detection may be elevated by a combination of external heating of molecular clouds, differential lensing, and/or pointing errors.IRAM NOEMA Interferometer [W16DX]; INSU/CNRS (France); MPG (Germany); IGN (Spain); U.S. National Science Foundation [AST-0955810, AST-1716585, AST-0408698, PHY-0855887, PHY-1214379]; Princeton University; University of Pennsylvania; Canada Foundation for Innovation (CFI); Comision Nacional de Investigacion Cientifica y Tecnologica de Chile (CONICYT); CONICYT [Anillo ACT-1417]; CFI under Compute Canada; Government of Ontario; Ontario Research Fund Research Excellence; University of TorontoThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu