APASS Landolt-Sloan BVgri photometry of RAVE stars. I. Data, effective temperatures and reddenings

摘要

We provide APASS photometry in the Landolt BV and Sloan g'r'i' bands for allthe 425,743 stars included in the latest 4th RAVE Data Release. The internalaccuracy of the APASS photometry of RAVE stars, expressed as error of the meanof data obtained and separately calibrated over a median of 4 distinctobserving epochs and distributed between 2009 and 2013, is 0.013, 0.012, 0.012,0.014 and 0.021 mag for B, V, g', r' and i' band, respectively. The equallyhigh external accuracy of APASS photometry has been verified on secondaryLandolt and Sloan photometric standard stars not involved in the APASScalibration process, and on a large body of literature data on field andcluster stars, confirming the absence of offsets and trends. Compared with theCarlsberg Meridian Catalog (CMC-15), APASS astrometry of RAVE stars is accurateto a median value of 0.098 arcsec. Brightness distribution functions for theRAVE stars have been derived in all bands. APASS photometry of RAVE stars,augmented by 2MASS JHK infrared data, has been chi2 fitted to a denselypopulated synthetic photometric library designed to widely explore intemperature, surface gravity, metallicity and reddening. Resulting Teff andE(B-V), computed over a range of options, are provided and discussed, and willbe kept updated in response to future APASS and RAVE data releases. In theprocess it is found that the reddening caused by an homogeneous slab of dust,extending for 140 pc on either side of the Galactic plane and responsible forE(B-V,poles)=0.036 +/- 0.002 at the galactic poles, is a suitable approximationof the actual reddening encountered at Galactic latitudes |b|>=25 deg.