Author(s): R. Yan, University of Kentucky, Lexington, Kentucky, UNITED STATES|
Institution(s): 1. University of Kentucky, Lexington, KY, United States.
Contributing team(s): MaStar Collaboration
As part of the fourth generation of Sloan Digital Sky Survey (SDSS-IV), the MaNGA Stellar Library (MaStar) project is constructing a large, well-calibrated, high quality empirical stellar library with more than 10,000 stars covering the wavelength range from 3622 to 10,354A at a resolution of R~2000. The spectra are taken using the same instrument as the integral field galaxy survey, Mapping Nearby Galaxies at Apache Point Observatory (MaNGA), by piggybacking on the Apache Point Observatory Galaxy Evolution Experiment-2N (APOGEE-2N) observations. The relative flux calibration of the library is accurate to 4.4% in g-r and 3% in r-i and i-z. The great majority of the stars are observed more than once, producing multiple "visit-spectra". The first version of the library contains 8646 high quality visit-spectra for 3321 unique stars. Compared to previous empirical libraries such as MILES, the MaStar Library has a more comprehensive and contiguous stellar parameter coverage, especially in the red giant branch, cool dwarfs, low metallicity stars, and stars with different [α/Fe]. This is achieved by a target selection method based on large spectroscopic catalogs from APOGEE, LAMOST, and SEGUE, combined with photometry-based selection and sources from the literature. This empirical library will provide a new basis for stellar population synthesis and is particularly well suited for stellar population analysis for MaNGA galaxies. The data are released in SDSS Data Release 15.