LEGUS
Legacy ExtraGalactic UV Survey

LEGUS Observations

HST Primary Observations

The primary observations consist of fifty local galaxies that are imaged with WFC3 using 5 filters (WFC3/F275W, F336W, F438W, F555W, F814W). Post-flash was applied to observations performed using filters F275W, F336W, and F438W. Images in all 5 filters will be obtained for most of the pointings. Only those targets with archival HST/ACS data will only be imaged in fewer filters. For a subset of the galaxies, small (2-4 pointings) mosaics will be obtained. There are a total of 63 primary pointings.
HST Parallel Observations

For each of the 63 pointings, parallel observations are being obtained in ACS/F435W, F814W and F606W depending on the target.

UV / optical comparison

The figure below shows a comparison of the UVIS LEGUS images of NGC 6503. Drag the slider to show (left) the optical mosaic created using filters F435W (blue), F555W (green), and F658N (red) and (right) the UV counterpart created using filters F275W (blue), F336W (green), and F435W (red).
before
after

Footprints

The figure below shows, as an example, the WFC3/UVIS and ACS/WFC footprints of the LEGUS and archival HST data of the interactive galaxy pair NGC5194 + NGC 5195 on a GALEX NUV background 800 pixels (20 arcmin) on each side .
Red footprints correspond to ACS archival data. The purple footprints represent the LEGUS WFC3/UVIS primary observations and the blue footprints represent the parallel ACS/WFC LEGUS observations.
Click to enlarge the figures below.