Scylla I: A pure-parallel, multi-wavelength imaging survey of the ULLYSES fields in the LMC and SMC

Named after the multi-headed monster from the myth of Ulysses, Scylla is a Hubble Space Telescope (HST) survey of the stellar populations, interstellar medium and star formation in the LMC and SMC. As a pure-parallel complement to the spectroscopic Ultraviolet (UV) Legacy Library of Young Stars as Essential Standards (ULLYSES) survey, Scylla surveyed fields parallel to ULLYSES targets with maximum photometric coverage from the near UV to the near-infrared (IR) with Wide Field Camera 3 (WFC3). All fields have been imaged in at least two filters - F475W and F814W. 64% of fields have been imaged in at least three and as many as seven WFC3 filters spanning the UV to IR. On average, Scylla reaches 50% completeness at mF225W = 26.0, mF275W = 26.2, mF336W = 26.9, mF475W = 27.8, mF814W = 25.5, mF110W = 24.7, and mF160W = 24.0 Vega magnitudes in its photometric catalogs, which is faintward of the ancient main sequence turnoff in all filters. Here the team provides images and photometric catalogs from the survey. These represent the widest-area coverage of the MCs with HST photometry to date.