On the Raman O VI and related lines in classical novae

Abstract

We critically examine the recent claimed detection of Raman scattered O VI at around 6830Å in the iron curtain stage spectra of the classical CO nova V339 Del. The observed line variations are compatible in profile and timing of emission line strength with an excited state transition of neutral carbon. Line formation in classical nova ejecta is physically very different from that in symbiotic binaries, in which the O VI emission line is formed within the wind of the companion red giant at low differential velocity. The ejecta velocity and density structure prevent the scattering from producing analogous features. There might , however, be a broadband spectropolarimetric signature of the Raman process and also Rayleigh scattering at some stage in the expansion. We show that the neutral carbon spectrum, hitherto under-exploited for novae, is especially useful as a probe of the structure of the ejecta during the early, optically thick stages of the expansion

arXiv commentA&A Letters (in press); submitted: 11/8/14; accepted: 10/9/14

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Cited by in corpus (6)

• M31N 2008-12a - the remarkable recurrent nova in M31: Pan-chromatic observations of the 2015 eruption
• The panchromatic spectroscopic evolution of the classical CO nova V339 Del (Nova Del 2013) until X-ray turnoff
• 500 days of Stromgren b, y and narrow-band [OIII], Ha photometric evolution of gamma-ray Nova Del 2013 (= V339 Del)
• Two New Nova Shells associated with V4362 Sagittarii and DO Aquilae
• RAMSES II - RAMan Search for Extragalactic Symbiotic Stars. Project concept, commissioning, and early results from the science verification phase
• A D'-type symbiotic binary in the planetary nebula SMP LMC 88