Near‐Infrared Emission Lines of V723 Cassiopeiae (Nova Cassiopeiae 1995)
2002; IOP Publishing; Volume: 573; Issue: 2 Linguagem: Inglês
10.1086/340943
ISSN1538-4357
AutoresR. J. Rudy, C. C. Venturini, D. K. Lynch, S. Mazuk, R. C. Puetter,
Tópico(s)Astrophysics and Star Formation Studies
ResumoNear-infrared spectroscopy (0.8-2.5 μm) from two epochs is presented for the very slow nova V723 Cassiopeiae (=Nova Cassiopeiae 1995). Its bright, comparatively narrow emission lines (FWHM ~ 500 km s-1) make it ideal for determining wavelengths of unidentified emission lines that appear in the nebular/coronal stages of novae. We present wavelengths for 16 previously unobserved or unidentified features and search for identifications by looking for coincidences with known atomic transitions. For a candidate transition, the likely abundance of the parent ion is considered and then a collisional, fluorescent, or recombination process capable of exciting the feature is sought. Four of the lines are identified in this manner, all of them collisionally excited, forbidden transitions. One of these, [Ti VII] λ22050, is a new coronal line that de-excites directly to the ground state. Three other lines are associated with transitions from collisionally excited, low-lying, metastable levels of Fe+5. Of the remaining unidentified features, five, with wavelengths of 8926, 11110, 11900, 15545, and 20996 Å, have been observed in other novae. Comparing the time development of these features with the [S VIII] λ9913 coronal line indicates that all have parent ions of lower excitation (<280 eV) than S+7.
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