Constraining the Origins of Cataclysmic Variables Through Abundance Studies of Their Secondary Stars

Ryan Hamilton

Ground based near-infrared (NIR) spectroscopy has opened the door to examining the mass losing secondary stars in cataclysmic variable (CV) systems. With moderate resolution (R > 1500) spectroscopy it is now possible to directly detect the secondary stars in over 60 systems across all CV subtypes. It has been shown that while most appear as expected for their spectral type, long period systems overwhelmingly show weaker than expected CO bands in the K-band. This could imply that the progenitors of CVs could be different, in terms of their own evolutionary history and time line. Synthetic spectra and modeling allow one to determine the abundances present in these NIR spectra, and assess whether the secondary stars are indeed the sources of the peculiar abundances that are also seen in ultraviolet observations. The goal of my Ph.D. thesis will be to better understand the origin and evolution of CVs through abundance analyses of their secondary stars.