Stacking of large interferometric data sets in the image- and uv-domain -- a comparative study

Abstract

We present a new algorithm for stacking radio interferometric data in the uv-domain. The performance of uv-stacking is compared to the stacking of fully imaged data using simulated Atacama Large Millimeter/sub-millimeter Array (ALMA) and the Karl G. Jansky Very Large Array (VLA) deep extragalactic surveys. We find that image- and uv-stacking produce similar results, however, uv-stacking is typically the more robust method. An advantage of the uv-stacking algorithm is the availability of uv-data post stacking, which makes it possible to identify and remove problematic baselines. For deep VLA surveys uv-stacking yields a signal-to-noise ratio that is up to 20 per cent higher than image-stacking. Furthermore, we have investigated stacking of resolved sources with a simulated VLA data set where 1.5" (10-12 kpc at z ~ 1-4) sources are stacked. We find that uv-stacking, where a model is fitted directly to the visibilities, significantly improves the accuracy and robustness of the size estimates. While scientific motivation for this work is studying faint, high-z galaxies, the algorithm analysed here would also be applicable in other fields of astronomy. Stacking of radio interferometric data is also expected to play a big role for future surveys with telescopes such as LOFAR and Square Kilometre Array (SKA).

15 pages, 12 figures, accepted for publication in MNRAS

References in corpus (8)

• The Cosmic Evolution Survey (COSMOS) -- Overview
• The Cosmic Infrared Background Resolved by Spitzer. Contributions of Mid-Infrared Galaxies to the Far-Infrared Background
• The non-coplanar baselines effect in radio interferometry: The W-Projection algorithm
• The VLA-COSMOS Survey: II. Source Catalog of the Large Project
• The VLA-COSMOS Survey: III. Further Catalog Analysis and the Radio Source Counts
• The VLA 1.4GHz Survey of the Extended Chandra Deep Field South: First Data Release
• The X-ray Properties of Early-Type Galaxies in the Extended Chandra Deep Field-South
• Star formation rates in Lyman break galaxies: radio stacking of LBGs in the COSMOS field and the sub-$\mu$Jy radio source population

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