Constraining Stellar Parameters for Hotter Stars in the MaStar Library
Abstract
MaStar is a large, comprehensive library of stellar spectra with wavelength coverage and instrumental resolution identical to that of the MaNGA galaxy survey. Part of the goal in creating MaStar is to produce a library with significantly improved parameter coverage in comparison to past libraries, including coverage of warm and hot stars. Here, we will present results from a stellar parameter determination method specifically designed for warmer stars (6,000 K < Teff < 12,000 K) in MaStar. For stars around 10,000K, the Balmer lines are not very sensitive to temperature changes, making it difficult to determine the stellar parameters using model fits to the entire stellar spectrum. We make use of the slope of the Balmer discontinuity and the shape of the heavily smoothed spectra, from the flux calibrated MaStar data, to help break the degeneracy between temperature, surface gravity, and extinction. With the latest ATLAS9-based theoretical spectral templates from Bohlin et al. (2015), we derive Teff, Log g, [Fe/H], and extinction using Bayesian inference. We compare the parameters with the results from other methods and Gaia-based luminosity estimates to verify their robustness.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23336318L