CoSHA: Code for Stellar Properties Heuristic Assignment-for the MaStar Stellar Library

We introduce CoSHA: a Code for Stellar properties Heuristic Assignment. In order to estimate the stellar properties, CoSHA implements a Gradient Tree Boosting algorithm to label each star across the parameter space (T-eff, log g , [Fe/H], and [alpha/Fe]). We use CoSHA to estimate the stellar atmospheric parameters of 22,000 unique stars in the MaNGA Stellar Library (MaStar). To quantify the reliability of our approach, we run internal tests, using both the Gottingen Stellar Library (a theoretical library) and the first data release of MaStar, and external tests, by comparing the resulting distributions in the parameter space with the APOGEE estimates of the same properties. In summary, our parameter estimates span the ranges T-eff = [2900, 12,000] K, log g = [-0.5,5.6], [Fe/H] = [-3.74, 0.81], and alpha M = [-0.22, 1.17]. We report internal (external) uncertainties of the properties of sigma(Teff) similar to 43(240) K, sigma(log g) similar to 0.2(0.4) 更多