Modelling high-resolution ALMA observations of strongly lensed dustystar forming galaxies detected by Herschel

TL;DR

This paper models high-resolution ALMA images of seven strongly lensed dusty star-forming galaxies from Herschel, revealing their intrinsic properties and lens mass profiles, with implications for understanding galaxy evolution.

Contribution

It provides detailed lens modeling of high-resolution ALMA data for multiple lensed galaxies, advancing understanding of their mass profiles and intrinsic characteristics.

Findings

Most lens models have near-isothermal mass density slopes.

Lensed sources exhibit high star formation rate to dust mass ratios.

Some systems show significant deviations from isothermal mass profiles.

Abstract

We present modelling of ~0.1arcsec resolution Atacama Large Millimetre/sub-millimeter Array imaging of seven strong gravitationally lensed galaxies detected by the Herschel Space Observatory. Four of these systems are galaxy-galaxy scale strong lenses, with the remaining three being group-scale lenses. Through careful modelling of visibilities, we infer the mass profiles of the lensing galaxies and by determining the magnification factors, we investigate the intrinsic properties and morphologies of the lensed sub-millimetre sources. We find that these sub-millimetre sources all have ratios of star formation rate to dust mass that is consistent with or in excess of the mean ratio for high-redshift sub-millimetre galaxies and low redshift ultra-luminous infrared galaxies. The contribution to the infrared luminosity from possible AGN is not quantified and so could be biasing our star formation rates to higher values. The majority of our lens models have mass density slopes close to isothermal, but some systems show significant differences.