Collaborative Research: A Large Stellar Library for Astronomical Research

New Mexico State University, Las Cruces NM

Investigators

Abstract

Astronomers need to know the detailed colors of stars ("spectra") at visible and infrared wavelengths to conduct research about stars, galaxies, and the regions outside of galaxies in the Universe (for example, understanding different groups of stars in galaxies). The libraries of stellar spectra that we have today do not offer enough high-quality information to use for the studies of today's astronomers. For this project, the investigators will build a large library of high-quality spectra for about 6000 stars using observations made on existing telescopes and instruments. This project will serve the national interest as it promotes the progress of research in astronomy by providing high-quality standards for astronomers to use to do their research. The investigators will make and use a teaching unit with a web app for introductory college astronomy education that will help students understand how astronomers can learn about populations of stars using spectra. They will also train graduate students and run outreach activities. Stellar spectral libraries underpin spectroscopic analysis in stellar, galactic, and extragalactic astronomy; they are fundamental for modeling stellar populations in galaxies. Existing empirical stellar libraries have poor sampling in several important parts of the stellar parameter space, do not provide adequate wavelength coverage and spectral resolution for the state-of-the-art galaxy surveys, and often have poor flux calibration. Theoretical stellar libraries are not yet realistic enough to match the observed colors of stars and galaxies; this reveals an incomplete understanding of important stellar physics. To address these problems, the investigators will build a large, well-calibrated, high quality empirical stellar library of ~6000 stars with much more extensive coverage of stellar parameter space than previous efforts. The spectra will cover the wavelength range of 3600-10,300Å at a resolution of R~2000, with better than 3% relative flux calibration. It will be achieved by conducting parallel optical observations piggybacking on the APOGEE-2 survey as part of Sloan Digital Sky Survey-IV. The investigators will develop and then use an instructional unit with a web app for college introductory astronomy education that will help students understand how astronomers can learn about the stellar populations of a galaxy from its spectrum. The investigators will also train graduate students and conduct outreach activities.