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Atypical dust species in the ejecta of classical novae

Published online by Cambridge University Press:  30 March 2011

L.A. Helton
Affiliation:
Department of Astronomy, School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, USA. e-mail: ahelton@astro.umn.edu; chelsea@astro.umn.edu; & gehrz@astro.umn.edu ;
A. Evans
Affiliation:
Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG, UK; e-mail: ae@astro.keele.ac.uk ;
C.E. Woodward
Affiliation:
Department of Astronomy, School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, USA. e-mail: ahelton@astro.umn.edu; chelsea@astro.umn.edu; & gehrz@astro.umn.edu ;
R.D. Gehrz
Affiliation:
Department of Astronomy, School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, USA. e-mail: ahelton@astro.umn.edu; chelsea@astro.umn.edu; & gehrz@astro.umn.edu ;

Abstract

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A classical nova outburst arises from a thermonuclear runaway in the hydrogen-rich material accreted onto the surface of a white dwarf in a binary system. These explosions can produce copious amounts of heavy element enriched material that are ejected violently into the surrounding interstellar medium. In some novae, conditions in the ejecta are suitable for the formation of dust of various compositions, including silicates, amorphous carbon, silicon carbide, and hydrocarbons. Multiple dust grain types are sometimes produced in the same system. CO formation in novae may not reach saturation, thus invalidating the usual paradigm in which the C:O ratio determines the dust species. A few novae, such as V705 Cas and DZ Cru, have exhibited emission features near 6, 8, and 11 μmthat are similar to “Unidentified Infrared” (UIR) features, but with significant differences in position and band structure. Here, we present Spitzer IRS spectra of two recent dusty novae, V2361 Cyg and V2362 Cyg, that harbor similar peculiar emission structures superimposed on features arising from carbonaceous grains. In other astronomical objects, such as star forming regions and young stellar objects, emission peaks at 6.2, 7.7, and 11.3 μmhave been associated with polycyclic aromatic hydrocarbon (PAH) complexes. We suggest that hydrogenated amorphous carbon (HAC) may be the source of these features in novae based upon the spectral behavior of the emission features and the conditions under which the dust formed.

Type
Research Article
Copyright
© EAS, EDP Sciences 2011

References

Allamandola, L.J., Tielens, A.G.G.M., & Barker, J.R., 1989, ApJS, 71, 733 CrossRef
Duley, W.W., & Williams, D.A., 1983, MNRAS, 205, 67P CrossRef
Evans, A., & Rawlings, J.M.C., 1994, MNRAS, 269, 427 CrossRef
Evans, A., Geballe, T.R., Rawlings, J.M.C., Eyres, S.P.S., & Davies, J.K., 1997, MNRAS, 292, 192 CrossRef
Evans, A., Tyne, V.H., Smith, O., et al., 2005, MNRAS, 360, 1483 CrossRef
Evans, A., & Rawlings, J.M.C., 2008, in Classical Novae, 2nd Edition, ed. M.F. Bode & A. Evans (Cambridge Univ. Press: Cambridge)
Evans, A., Gehrz, R.D., Woodward, C.E., et al., 2010, MNRAS, 406, 85
Geballe, T.R., 1997, From Stardust to Planetesimals, 122, 119
Gehrz, R.D., 2008, in Classical Novae, 2nd Edition, ed. M.F. Bode & A. Evans(Cambridge Univ. Press: Cambridge)
Gehrz, R.D., 1992, ApJ, 400, 671 CrossRef
Ivezić, Ž., Nenkova, M., & Elitzer, M., 1999 [arXiv:astro-ph/9910475]
Lynch, D.K., Woodward, C.E., Gehrz, R.D., et al., 2008, AJ, 136, 1815 CrossRef
Peeters, E., Hony, S., Van Kerckhoven, C., et al., 2002, A&A, 390, 1089
Sloan, G.C., Jura, M., Duley, W.W., et al., 2007, ApJ, 664, 1144 CrossRef
Sloan, G.C., Bregman, J.D., Geballe, T.R., Allamandola, L.J., & Woodward, C.E., 1997, ApJ, 474, 735 CrossRef
van Diedenhoven, B., Peeters, E., Van Kerckhoven, C., et al., 2004, ApJ, 611, 928 CrossRef