Precision distances to dwarf galaxies and globular clusters from Pan-STARRS1 3π RR Lyrae.

We present new spatial models and distance estimates for globular clusters and dwarf spheroidals orbiting our Galaxy based on RR Lyrae (RRab) stars in the Pan-STARRS1 (PS1) 3 pi survey. Using the PS1 sample of RRab stars from Sesar et al. in 16 globular clusters and 5 dwarf galaxies, we fit structural models in (l, b, D) space; for 13 globular clusters and 6 dwarf galaxies, we give only their mean heliocentric distance D. We verify the accuracy of the period-luminosity relations used in Sesar et al. to constrain the distance to those stars, and compare them to period-luminosity-metallicity relations using metallicities from Carretta et al. We compare our Sesar et al. distances to the parallax-based Gaia DR2 distance estimates from Bailer-Jones et al. and find our distances to be consistent and considerably more precise.