Stellar spectra libraries are an essential tool for a wide range of astronomical research. The MaStar project has produced the largest library of high quality stellar spectra up to date. In this value-added catalog, we present stellar parameter measurements using several different methods.
Many applications of the library depend on having accurate stellar parameters for each spectrum. The MaStar working group has carried out multiple efforts to derive stellar parameters using different methods. Here we combine the multiple sets of parameters into a single value-added catalog, containing both the individual sets of stellar parameters and a master set combining the best measurements from all sets. The stellar parameters we present include the effective temperature (T_eff), the surface gravity (log g), the Iron-to-Hydrogen ratio ([Fe/H]), the total metallicity ([Z/H]), and the Alpha-to-Iron ratio ([alpha/Fe]).
Different methods and templates are used to derive the parameters. In the catalog these are labelled as DL (led by Daniel Lazarz at University of Kentucky), JI (led by Julie Imig at New Mexico State University), LH (led by Lewis Hill at University of Portsmouth), YC (led by Yanping Chen at New York University Abu Dhabi). These methods are described in detail on the MaStar Stellar Parameters webpage.
There are two versions of this VAC. Version 1 (v1) was released on Dec 7, 2021 and version 2 (v2) was released in September 2022.
In v2, three of the four parameter measurement methods (DL, LH, and YC) were updated to produce more accurate and robust measurements, with better quality control. Therefore, we recommend using v2 for all purposes. Both versions are available on the Science Archive Server (SAS). On the Catalog Archive Server (CAS), v1 is available under the DR17 context and v2 will be available under the DR18 context (expected in December 2022).
