Transformations between WISE and 2MASS, SDSS, BVI photometric systems: II. Transformation equations for red clump stars

Abstract

We present colour transformations for the conversion of the Wide-Field Survey Explorer (WISE) W1, W2, and W3 magnitudes to the Johnson-Cousins (BVIc), Sloan Digital Sky Survey (gri), and Two Micron All Sky Survey JHKs photometric systems, for red clump (RC) stars. RC stars were selected from the Third Radial Velocity Experiment (RAVE) Data Release (DR3). The apparent magnitudes were collected by matching the coordinates of this sample with different photometric catalogues. The final sample (355 RC stars) used to obtain metallicity dependent-and free of metallicity- transformations between WISE and Johnson-Cousins, SDSS, 2MASS photometric systems. These transformations combined with known absolute magnitudes at shorter wavelengths can be used in space density determinations for the Galactic (thin and thick) discs at distances larger than the ones evaluated with JHKs photometry alone, hence providing a powerful tool in the analysis of Galactic structure.