ELEMENTAL ABUNDANCES IN THE EJECTA OF OLD CLASSICAL NOVAE FROM LATE-EPOCH<i>SPITZER</i>SPECTRA

Helton, L. A.; Gehrz, R. D.; Woodward, C. E.; Wagner, R. M.; Vacca, William D.; Evans, A.; Krautter, J.; Schwarz, Greg J.; Shenoy, D.; Starrfield, S.

doi:10.1088/0004-637x/755/1/37

Cited by 34 publications

(39 citation statements)

References 83 publications

(129 reference statements)

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“…The change can be reproduced using a progressively greater inner angle, varying as shown in Fig. 14 Helton et al (2012) found the same behavior for the infrared neon lines (see their Fig. 5).…”

Section: Modeling the Structure Of The Ejectasupporting

confidence: 57%

The spectroscopic evolution of theγ-ray emitting classical nova Nova Mon 2012

Shore¹,

Aquino²,

Schwarz³

et al. 2013

A&A

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Among the classical novae, the ONe subgroup, distinguished by their large overabundance of neon, are thought to occur on the most massive white dwarfs. Nova Mon 2012 was the first classical nova to be detected as a high energy γ-ray transient, by Fermi-LAT, before its optical discovery. The first optical spectra obtained about 55 days after γ-ray peak, were strikingly similar to the ONe class after the transition to the nebular (optically thin) spectrum. The current paper presents our subsequent optical and ultraviolet observations. A time sequence of optical echelle spectra (3700-7400Å) with the Nordic Optical Telescope (NOT) began on 2012 Aug. 16, immediately following the optical announcement, and are continuing. The nova was observed almost simultaneously with the NOT on 2012 Nov. 21, with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope at medium echelle resolution (1150-3050Å) on Nov. 20, and with the CHIRON CTIO/SMARTS echelle spectrograph at medium resolution (4500-8900Å) on Nov. 22. We use plasma diagnostics (e.g. [O III] and Hβ line flux) to constrain electron densities and temperatures, and the filling factor, for the ejecta. Using Monte Carlo modeling, we derive the structure from comparisons to the optical and ultraviolet line profiles. We also compare observed fluxes for Nova Mon 2012 with those predicted by photoionization modeling with Cloudy using element abundances derived for other ONe novae, the parameters derived from the line profile modeling and multiwavelength continuum measurements. Nova Mon 2012 is confirmed as an ONe nova first observed spectroscopically in the nebular stage. We derive an extinction of E(B-V)=0.85±0.05 and hydrogen column density N H ≈ 5 × 10 21 cm −2 . The corrected continuum luminosity is nearly the same in the entire observed energy range compared to V1974 Cyg, V382 Mon, and Nova LMC 2000 at the same epoch after outburst. The distance, about 3.6 kpc, is quite similar to V1974 Cyg, suggesting that it would have been equally bright had it been observed at maximum light. The same applies to the line profiles. These can be modeled using an axisymmetric conical -bipolargeometry for the ejecta with various inclinations of the axis to the line of sight, i, and ejecta inner radii. For Nova Mon 2012, we find that 60 ≤ i ≤ 80 degrees, an opening angle of ≈70 o , and an inner radius ∆R/R(t) ≈ 0.4 matches the permitted and intercombination lines while the forbidden lines require a less filled structure. The filling factor is f ≈ 0.1 − 0.3, although it may be lower based on the structures observed in the emission line profiles, implying an ejecta mass ≤ 6 × 10 −5 M ⊙ . The abundances are similar to, but not identical to, V1974 Cyg and V382 Vel. In particular, Ne and Mg are apparently more abundant in Nova Mon 2012. The ONe novae appear to comprise a single physical class with bipolar high mass ejecta, similarly enhanced abundances, and a common spectroscopic evolution within a narrow range of luminosities. The spectral evolution does not require c...

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Section: Modeling the Structure Of The Ejectasupporting

confidence: 57%

The spectroscopic evolution of theγ-ray emitting classical nova Nova Mon 2012

Shore¹,

Aquino²,

Schwarz³

et al. 2013

A&A

View full text Add to dashboard Cite

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“…2) however resembles a modified black body at ∼ 15 − 50 K (KMT), somewhat warmer than would be expected for dust produced in a CN eruption in 1670 and cooling as it flows away from the site of the eruption. By comparison, no dust was detected in a Spitzer observation of the dusty CN NQ Vul some 27.5 years after eruption (Helton et al 2012).…”

Section: Comparison With Nova Uir Featuresmentioning

confidence: 87%

“…The [O IV] 2 P 3/2 − 2 P 1/2 25.890 µm line, which is ubiquitous in mature CNe (Helton et al 2012) and common (but not universal) in PNe (Stanghellini et al 2012), is clearly present. However its full-width half-maximum (0.54 µm) is significantly greater than that of the other lines (∼ 0.3 µm), suggesting that there may be a contribution from another species.…”

Section: Ionic Linesmentioning

confidence: 99%

CK Vul: a smorgasbord of hydrocarbons rules out a 1670 nova (and much else besides)

Evans¹,

Gehrz²,

Woodward³

et al. 2016

Mon. Not. R. Astron. Soc.

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We present observations of CK Vul obtained with the Spitzer Space Telescope. The infrared spectrum reveals a warm dust continuum with nebular, molecular hydrogen and HCN lines superimposed, together with the "Unidentified Infrared" (UIR) features. The nebular lines are consistent with emission by a low density gas. We conclude that the Spitzer data, combined with other information, are incompatible with CK Vul being a classical nova remnant in "hibernation" after the event of 1670, a "Very Late Thermal Pulse", a "Luminous Red Variable" such as V838 Mon, or a "Diffusion-induced nova". The true nature of CK Vul remains a mystery.

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“…Neon is one of the most abundant elements in space and has been detected in various interstellar objects in various spectral regions (Helton et al 2012;Pandey & Lambert 2011;Takeda et al 2010;Smith et al 2009;Gehrz et al 2008;Baldovin-Saavedra et al 2011). An estimation of this α-element's abundance in stars and star-forming regions provides useful information on the metallicity and rates of formation of these objects (Ho & Keto 2007).…”

Section: Introductionmentioning

confidence: 99%

FTIR laboratory measurement of Ne i Rydberg states in 1.43−14.3μm spectral range

Kubelík

Civiš

Pastorek

et al. 2015

A&A

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Context. The Ne i spectrum in the 800−1800 cm −1 (5.55−14.3 μm) domain has not been previously investigated.Aims. To address this spectral gap, we performed high-resolution laboratory measurements of the Ne i emission spectrum over the 800−7000 cm −1 (1.43−14.3 μm) range.Methods. The Ne i laboratory spectra were obtained from a pulsed discharge plasma and recorded using time-resolved Fourier transform spectroscopy. The identification of the spectral lines was performed according to the transition probability values calculated using the quantum defect method.Results. Based on these measurements, we report the wavenumbers of 151 Ne i lines and energy values for 14 Ne i levels that are not listed in the available databases.

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ELEMENTAL ABUNDANCES IN THE EJECTA OF OLD CLASSICAL NOVAE FROM LATE-EPOCHSPITZERSPECTRA

Cited by 34 publications

References 83 publications

The spectroscopic evolution of theγ-ray emitting classical nova Nova Mon 2012

The spectroscopic evolution of theγ-ray emitting classical nova Nova Mon 2012

CK Vul: a smorgasbord of hydrocarbons rules out a 1670 nova (and much else besides)

FTIR laboratory measurement of Ne i Rydberg states in 1.43−14.3μm spectral range

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