The Impact of $\text{CLEAN}$ing on Strong Gravitational Lens Modelling

Abstract

We present a comparison of image and uv-plane galaxy-galaxy strong lensing modelling results for simulated ALMA observations with different antenna configurations and on-source integration times. Image-plane modelling is carried out via use of the $\text{CLEAN}$ algorithm, and we explore the effects of different visibility weighting schemes on the inferred lens model parameters. We find that direct modelling of the visibility data consistently outperforms image-plane modelling for both the naturally and Briggs-weighted images. We also find that the modelling of images created with Briggs weighting generally produces more accurate results than those obtained by modelling images constructed with natural weighting. We explain this by quantifying the suppression of information due to $\text{CLEAN}$ing on scales at which the modelling is sensitive, and how this differs between Briggs and natural weighting. At higher resolutions, the differences between the lens modelling techniques are much less pronounced and overall, modelling errors are significantly reduced. We also find that time-binning the visibilities by up to a factor of three makes no significant difference to the inferred lens parameters when directly modelling in the uv-plane. This work provides some guidance on navigating the many choices faced when modelling strong lens interferometric imaging data.

18 pages, 22 figures

References in corpus (14)

• A dynamically cold disk galaxy in the early Universe
• z~2-9 Galaxies Magnified by the Hubble Frontier Field Clusters II: Luminosity Functions and Constraints on a Faint-End Turnover
• Strong lensing time-delay cosmography in the 2020s
• PyAutoLens: Open-Source Strong Gravitational Lensing
• Automated galaxy-galaxy strong lens modelling: no lens left behind
• ALMA Lensing Cluster Survey: ALMA-Herschel Joint Study of Lensed Dusty Star-Forming Galaxies across $z\simeq 0.5-6$
• Early-type galaxy density profiles from IllustrisTNG: II. Evolutionary trend of the total density profile
• Close-up view of a luminous star-forming galaxy at z=2.95
• A High-Resolution Investigation of the Multi-Phase ISM in a Galaxy during the First Two Billion Years
• Beyond the bulge-halo conspiracy? Density profiles of Early-type galaxies from extended-source strong lensing
• Testing strong lensing subhalo detection with a cosmological simulation
• Time-Delay Cosmography: Measuring the Hubble Constant and other cosmological parameters with strong gravitational lensing
• Modelling high-resolution ALMA observations of strongly lensed dustystar forming galaxies detected by Herschel
• Probing General Relativity in galactic scales at z $\sim 0.3$

Cited by in corpus (1)

• Hiding behind a curtain of dust: Gas and dust properties of an ultra-luminous strongly-lensed z = 3.75 galaxy behind the Milky Way disk