PHAS Colloquia

4D Radio Astronomy with the VLA Sky Survey

by Dr Dillon Dong

America/Chicago
Description

In October 2024, the VLA Sky Survey (VLASS) completed its third full epoch,

conducting sensitive, high-resolution 3 GHz observations of all ~34,000 deg²

accessible to the VLA for the third time since 2017. Thanks to the efforts of the

VLASS team, all observations have now been calibrated and “quicklook”

imaged, enabling high-quality, multi-epoch measurements of ~99% of the

surveyed area. The ~106,000 quicklook images represent a ~2 order of

magnitude reduction in volume from the raw visibilities, transforming a

~petabyte-scale problem to a straightforwardly manageable ~5 TB dataset. In

this talk, I will discuss several ongoing efforts to distill these data further (into

data products and science) and make them readily available to all. This will

include a preview of the VLASS transient, variable and persistent source

catalogs and efficient/robust means of crossmatching these sources to multi-

wavelength counterparts, and a new VLASS image cutout server capable of

delivering cutouts at arbitrary locations in ~100 milliseconds per coordinate. I

will additionally talk about the vast luminosity range of synchrotron-emitting

sources and what we might learn from our ever-more-complete sampling of

GHz-frequency radio photons in space and time.