2015/03/30 by John M. Brewer, Debra A. Fischer, Sarbani Basu +3 · 66 citations
Mathematics · Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Computational physics #Computer science #Effective temperature #Geometry #Line (geometry) #Mathematics #Offset (computer science) #Optics #Physics #Radiative transfer #Spectral line #Spectroscopy #Stars #Stellar, planetary, and galactic studies #Surface gravity #astro-ph.IM #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/805/2/126
published in The Astrophysical Journal 805(2), 126 (IOP Publishing) · Accepted to Apj, March 30, 2015; 10 pages, 6 figures
arxiv created 2015/03/30 · openalex publication_date 2015/05/28 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We demonstrate a new procedure to derive accurate and precise surface gravities from high resolution spectra without the use of external constraints. Our analysis utilizes Spectroscopy Made Easy with robust spectral line constraints and uses an iterative process to mitigate degeneracies in the fitting process. We adopt an updated radiative transfer code, a new treatment for neutral perturber broadening, a line list with multiple gravity constraints and separate fitting for global stellar properties and abundance determinations. To investigate the sources of temperature dependent trends in determining noted in previous studies, we obtained Keck HIRES spectra of 42 Kepler asteroseismic stars. In comparison to asteroseismically determined our spectroscopic analysis has a constant offset of 0.01 dex with a rms scatter of 0.05 dex. We also analyzed 30 spectra which had published surface gravities determined using the technique from planetary transits and found a constant offset of 0.06 dex and rms scatter of 0.07 dex. The two samples covered effective temperatures between 5000 and 6700 K with between 3.7 and 4.6.