University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Monday, October 14th 2019
12:15 pm:
Speaker: Zach Pace, U-Wisconsin, Madison
Subject:  Kiloparsec-resolved and galaxy-integrated stellar masses in the SDSS-IV/MaNGA survey

A galaxy's stellar mass is one of its most fundamental properties, but it remains challenging to measure reliably, as there are important degeneracies between stellar age, metallicity, and interstellar dust. Furthermore, with the advent of very large optical spectroscopic surveys, efficient methods that operate reliably on low signal-to-noise spectra are needed. I present a method for inferring properties of stellar populations, which relies on a library of composite stellar populations, and obtains a low-dimensional spectral basis set through principal component analysis (PCA) of the associated model spectra. This method is used to estimate resolved stellar mass-to-light ratios for ~6500 galaxies in the MaNGA survey. I will then discuss the tension between these estimates and those of dynamical mass surface density from the DiskMass survey, outline the hazards of relying on galaxy-integrated stellar mass-to-light estimates, and finally show some preliminary results that compare atomic gas content, stellar mass, and radial gas-phase metallicity variations.

Faculty Host: Lucy Fortson

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