DustPedia: Multiwavelength Photometry and Imagery of 875 Nearby Galaxies
  in 42 Ultraviolet--Microwave Bands
  The DustPedia project is capitalising on the legacy of the Herschel Space
Observatory, using cutting-edge modelling techniques to study dust in the 875
DustPedia galaxies - representing the vast majority of extended galaxies within
3000 km s$^{-1}$ that were observed by Herschel. This work requires a database
of multiwavelength imagery and photometry that greatly exceeds the scope (in
terms of wavelength coverage and number of galaxies) of any previous
local-Universe survey. We constructed a database containing our own custom
Herschel reductions, along with standardised archival observations from GALEX,
SDSS, DSS, 2MASS, WISE, Spitzer, and Planck. Using these data, we performed
consistent aperture-matched photometry, which we combined with external
supplementary photometry from IRAS and Planck. We present our multiwavelength
imagery and photometry across 42 UV-microwave bands for the 875 DustPedia
galaxies. Our aperture-matched photometry, combined with the external
supplementary photometry, represents a total of 21,857 photometric
measurements. A typical DustPedia galaxy has multiwavelength photometry
spanning 25 bands. We also present the Comprehensive & Adaptable Aperture
Photometry Routine (CAAPR), the pipeline we developed to carry out our
aperture-matched photometry. CAAPR is designed to produce consistent photometry
for the enormous range of galaxy and observation types in our data. In
particular, CAAPR is able to determine robust cross-compatible uncertainties,
thanks to a novel method for reliably extrapolating the aperture noise for
observations that cover a very limited amount of background. Our rich database
of imagery and photometry is being made available to the community
