Released observations

All raw observational data from the imaging surveys through the first year of survey observations (1 July 2019 – 30 June 2020) are released. The survey medium-deep observations during this period were focused on  the Perseus-Pisces region, with an additional medium-deep field in the HETDEX region. The wide tier of the survey focused on the HETDEX region (for overlap with the LoTSS DR1), with additional coverage in the Herschel-ATLAS North Galactic Cap, and in the fall sky between 22h-0h. In total, there are 218 observations; 65 of these observations build repeated coverage of nine medium-deep fields. There are observations of 160 unique fields; with an effective field-of-view (based on spacing between fields) of 6.44 square degrees, the released observations cover just over 1000 square degrees of sky.

Figure 1 shows the sky coverage of released observations, with the full four-year survey footprint shown for reference. The color coding indicates the version of the pipeline used for processing (see “Apercal versions applicable to the release” for details), where “None” means no processing was performed (see “Notes on specific observations“). “AMES” refers to observations in the medium-deep footprint, and Figure 2 shows these repeated medium-deep fields separately as individual observations of a field may be processed by different versions of the pipeline.

Figure 1. The sky coverage of released observations, with the full four-year survey footprint shown for reference. The color coding indicates the version of the pipeline used for processing (see “Apercal versions applicable to the release” for details).

Figure 2. A view of the processing for medium-deep fields with repeat visits. The observations are ordered in time-order and the color code refers to the same processing as for the figure above.

Notes on the data quality/processing  for specific observations can be found here.

A machine-readable summary table of these observations can be exported using the VO infrastructure, more details are provided in section “User Interfaces”.