MID-INFRARED PERIOD-METALLICITY-LUMINOSITY RELATIONS AND KINEMATICS OF RR LYRAE VARIABLES

We use ALLWISE data release W1- and W2-band epoch photometry collected by the Wide-Field Infrared Survey Explorer (WISE) to determine slopes of the period-luminosity relations for RR Lyrae stars in 15 globular clusters in the corresponding bands. We further combine these results with V- and K-band photometry of Galactic eld RR Lyrae stars to determine the metallicity slopes of the log P F -[Fe/H]-M K , log P F - [Fe/H]-M W1 , and log P F - [Fe/H]- M W2 period-metallicity-luminosity relations. We infer the zero points of these relations and determine the kinematical parameters of thick-disk and halo RR Lyraes via statistical parallax, and estimate the RR Lyrae-based distances to 18 Local-Group galaxies including the center of the Milky Way.