VLA imaging of the XMM-LSS / VIDEO deep field at 1-2 GHz

TL;DR

This paper presents deep 1-2 GHz radio imaging of the XMM-LSS/VIDEO field using the upgraded VLA, achieving improved survey speed, sensitivity, and source cataloging, facilitating studies of star-forming galaxies and black hole activity.

Contribution

First deep 1-2 GHz VLA imaging of the XMM-LSS/VIDEO field with enhanced survey efficiency and detailed source catalog, spectral indices, and positional accuracy.

Findings

Achieved median depth of 16 μJy/beam with 4.5 arcsec resolution.

Catalog contains 5,762 sources with in-band spectral indices for 60%.

Survey speed increased by 2.5 times compared to previous observations.

Abstract

Modern radio telescopes are routinely reaching depths where normal starforming galaxies are the dominant observed population. Realising the potential of radio as a tracer of star formation and black hole activity over cosmic time involves achieving such depths over representative volumes, with radio forming part of a larger multiwavelength campaign. In pursuit of this we used the Karl G. Jansky Very Large Array (VLA) to image $\sim$5 deg$^{2}$ of the VIDEO/XMM-LSS extragalactic deep field at 1--2 GHz. We achieve a median depth of 16 $\mu$Jy beam$^{-1}$ with an angular resolution of 4.5\arcsec. Comparisons with existing radio observations of XMM-LSS showcase the improved survey speed of the upgraded VLA: we cover 2.5 times the area and increase the depth by $\sim$20\% in 40\% of the time. Direction-dependent calibration and wide-field imaging were required to suppress the error patterns from off-axis sources of even modest brightness. We derive a catalogue containing 5,762 sources from the final mosaic. Sub-band imaging provides in-band spectral indices for 3,458 (60\%) sources, with the average spectrum becoming flatter than the canonical synchrotron slope below 1 mJy. Positional and flux-density accuracy of the observations, and the differential source counts are in excellent agreement with those of existing measurements. A public release of the images and catalogue accompanies this article.