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arXiv · 1811.10808

Precision distances to dwarf galaxies and globular clusters from Pan-STARRS1 3$\pi$ RR Lyrae

Nina Hernitschek·Judith G. Cohen·Hans-Walter Rix·Eugene Magnier·Nigel Metcalfe·Richard Wainscoat·Christopher Waters·Rolf-Peter Kudritzki·William Burgett
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Abstract

We present new spatial models and distance estimates for globular clusters (GC) and dwarf spheroidals (dSphs) 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. (2017) 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 (PL) relations used in Sesar et al. (2017) to constrain the distance to those stars, and compare them to period-luminosity-metallicity (PLZ) relations using metallicities from Carretta et al. (2009). We compare our Sesar et al. (2017) distances to the parallax-based \textit{Gaia} DR2 distance estimates from Bailer-Jones et al. (2018), and find our distances to be consistent and considerably more precise.

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Nina Hernitschek, Judith G. Cohen, Hans-Walter Rix, Eugene Magnier, Nigel Metcalfe, Richard Wainscoat, Christopher Waters, Rolf-Peter Kudritzki, William Burgett. 2018-11-27. Precision distances to dwarf galaxies and globular clusters from Pan-STARRS1 3$\pi$ RR Lyrae. https://doi.org/10.3847/1538-4357%2Faaf388

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