Author(s): Justus Gibson1, Robert E Stencel1
Institution(s): 1. University of Denver
Contributing team(s): The ARCES Team: W.Ketzeback (ApachePointObservatory - APO), J.Barentine (DarkSkyAssociation), A.Bradley (APO), J.Coughlin (SETI Institute), J.Dembicky (APO), S.Hawley (Washington), J.Huehnerhoff (Washington), R.Leadbeater (ThreeHillsObservatory), R.McMillan (APO), G.Saurage (SOFIA), S.Schmidt (OhioState), N.Ule (NewMexicoState), G.Wallerstein (Washington), and D.York (Chicago)
Worldwide interest in the recent eclipse of epsilon Aurigae resulted in the generation of several extensive data sets, including high resolution spectroscopic monitoring. This lead to the discovery, among other things, of the existence of a mass transfer stream, seen notably during third contact. We explored spectroscopic facets of the mass transfer stream during third contact, using high resolution spectra obtained with the ARCES and TripleSpec instruments at Apache Point Observatory. One hundred and sixteen epochs of data were obtained between 2009 and 2012, and equivalent widths and line velocities measured for high versus low eccentricity accretion disk lines. These datasets also enable greater detail to be measured of the mid-eclipse enhancement of the He I 10830A line, and the discovery of the P Cygni shape of the Pa-beta line at third contact. We found evidence of higher speed material, associated with the mass transfer stream, persisting between third and fourth eclipse contacts. We visualized the disk and stream interaction using SHAPE software, and used CLOUDY software to estimate that the source of the enhanced He I 10830A absorption arises from a region with log nH = 11 cm-3 and temperature of 20,000 K, consistent with a mid-B type central star. We thank the following for their contributions to this paper: William Ketzeback, John Barentine, Jeffrey Coughlin, Robin Leadbeater, Gabrelle Saurage, and others. This paper has been submitted to Monthly Notices.