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

Journal article

Modern radio telescopes are routinely reaching depths where normal star-forming galaxies are the dominant observed population. Realizing 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 ∼5 deg2 of the VIDEO/XMM-LSS extragalactic deep field at 1–2 GHz. We achieve a median depth of 16 µJy 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 ∼20 per cent in 40 per cent 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 5762 sources from the final mosaic. Sub-band imaging provides in-band spectral indices for 3458 (60 per cent) 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.

Authors: Jarvis, MJ; Heywood, I; Hale, CL; Makhathini, S; Peters, JA

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Astronomical Society
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 496
• Issue: 3
• Pages: 3469-3481
• Publication date: 2020-06-20
• Acceptance date: 2020-06-10
• DOI: 10.1093/mnras/staa1770
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: radio continuum: galaxies; techniques: interferometric; FFR