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D.K. Lynch, R.J. Rudy, C.C. Venturini, S. Mazuk (The Aerospace Corp.), R.C. Puetter (UCSD/CASS)
We report spectroscopy of a number of recent novae or recurrent novae. Near infrared spectroscopy provides a wealth of diagnostic detail about novae and the evolution of their shells because of the number and variety of special-utility lines that are available. Low excitation hydrogen Paschen and Brackett lines provide a background against which to assess abundances, electron densities and temperatures. They also reveal information about the shell geometry, kinematics and optical depths. The intrinsic flux ratio of the OI lines at 0.8446 \mu m and 1.1287 \mu m is well known and therefore any departure from it is usually a good indicator of interstellar reddening. Neutral and low ionization permitted lines of nitrogen, oxygen, carbon, phosphorus, silicon, calcium, magnesium and iron often provide crucial abundance information which in turn can be related to the initial composition, evolutionary state and surface mixing of the white dwarf (WD) before the outburst . As the ejecta cools and thins to reveal the hot WD, higher ionization forbidden ``coronal" lines begin to appear such as [S VIII] 0.9913 \mu m, [Fe XIII] 1.0747, [S IX] 1.2523 \mu m, [Al IX] 2.0469 \mu m, [Ca VIII] 2.3214 \mu m, and [Si VII] 2.4827 \mu m . By noting their relative strengths, time of emergence and critical densities, much can be learned about the conditions in the shell. Our spectra show a variety of line widths, shapes and levels of excitation. Of particular interest are the lines that have remained unidentified in these and other novae spectra. This work supported by The Aerospace Corporation's Independent Research and Development Program.
Also see posters by Rudy et al. and Venturini et al. .
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