Quantifying the Carbon Abundances in the Secondary Stars of SS Cygni, RU Pegasi, and GK Persei [SSA]

http://arxiv.org/abs/1509.03664


We use a modified version of MOOG to generate large grids of synthetic spectra in an attempt to derive quantitative abundances for three CVs (GK Per, RU Peg, and SS Cyg) by comparing the models to moderate resolution (R $\sim$ 25,000) $K$-band spectra obtained with NIRSPEC on Keck. For each of the three systems we find solar, or slightly sub-solar values for [Fe/H], but significant deficits of carbon: for SS Cyg we find [C/Fe] = $-$0.50, for RU Peg [C/Fe] = $-$0.75, and for GK Per [C/Fe] = $-$1.00. We show that it is possible to use lower resolution (R $\sim$ 2,000) spectra to quantify carbon deficits. We examine realistic veiling scenarios and find that emission from H I or CO cannot reproduce the observations.

Read this paper on arXiv…

T. Harrison and R. Hamilton
Tue, 15 Sep 15
74/83

Comments: Accepted in the Astronomical Journal