The Late Appearance of He<scp>i</scp>in V445 Puppis

Lynch, D. K.; Rudy, R. J.; Mazuk, S.; Venturini, C. C.; Puetter, R. C.; Perry, R. B.

doi:10.1086/425889

Cited by 17 publications

(25 citation statements)

References 6 publications

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“…Table 2 for line identifications in the 0.8-4.5 μm region). The six unidentified lines that frequently appear in novae at 1.1114, 1.1901, 1.5545, 2.0996, and 2.425 μm (Williams et al 1996;Lynch et al 2001Lynch et al , 2004 were not evident. On or immediately after 2006 November 30, dust formed and changed the spectral energy distribution (SED) of the nova shell.…”

Section: Observationsmentioning

confidence: 88%

NOVA V2362 CYGNI (NOVA CYGNI 2006):SPITZER,SWIFT, AND GROUND-BASED SPECTRAL EVOLUTION

Lynch

Woodward

Gehrz

et al. 2008

The Astronomical Journal

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Nova V2362 Cygni has undergone a number of very unusual changes. Ground-based spectroscopy initially revealed a normal sequence of events: the object faded and its near-infrared emission lines gradually shifted to higher excitation conditions until about day 100 when the optical fading reversed and the object slowly brightened. This was accompanied by a rise in the Swift X-ray telescope flux and a sudden shift in excitation of the visible and IR spectrum back to low levels. The new lower excitation spectrum revealed broad line widths and many P-Cygni profiles, all indicative of the ejection of a second shell. Eventually, dust formed, the X-ray brightnessapparently unaffected by dust formation-peaked and then declined, and the object faded at all wavelengths. The Spitzer dust spectra revealed a number of solid-state emission features that, at this time, are not identified.

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Section: Observationsmentioning

confidence: 88%

NOVA V2362 CYGNI (NOVA CYGNI 2006):SPITZER,SWIFT, AND GROUND-BASED SPECTRAL EVOLUTION

Lynch

Woodward

Gehrz

et al. 2008

The Astronomical Journal

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“…The excitation of the system was also sufficient to produce emission lines of He ii. Interestingly, some of the common coronal lines (e.g., [Ca viii Rudy et al (2002) and seen in several other novae (Williams, Longmore, & Geballe 1996;Lynch et al 2001;Venturini et al 2002) are present, but these appear to require only moderate excitation to exist. (Williams, Longmore, & Geballe [1996] identified the feature at 1.5545 lm with the hydrogenic 10-9 transition of N v, but Rudy et al [2002] rejected this identification based on the width of the feature, and the absence of the 9-8 multiplet and several other transitions from lower levels.)…”

Section: Late-time Spectrummentioning

confidence: 99%

Near‐Infrared Spectrophotometry and the CO Emission in V2274 Cygni (Nova Cygni 2001 No. 1)

Rudy

Dimpfl

Lynch

et al. 2003

ApJ

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Infrared spectroscopy of V2274 Cygni (=Nova Cygni 2001 No. 1) is presented for two widely separated epochs, 17 and 370 days after discovery. In addition to the Paschen and Brackett series of H i, the early-time spectrum shows strong emission lines of C i and N i, fluorescently excited lines of O i, and emission from the first overtone of carbon monoxide. Because the initial data were probably acquired no more than 18 days after outburst, CO molecule formation occurred remarkably quickly in the dense, cool, carbon and oxygen rich ejecta. Rapid formation was also seen in NQ Vul, V842 Cen, and V705 Cas, three other novae in which first-overtone CO emission has been detected. Formation of the CO molecule may occur chemically in a process that requires H 2 as a precursor or directly through radiative association. The overtone emission of V2274 Cyg indicates a temperature of $2500 K. The vibrational levels show no obvious departures from thermal equilibrium, which may indicate high optical depths in the fundamental. A large 13 C/ 12 C ratio (0:83 AE 0:3) is also indicated by the observations, consistent with the fast CNO burning expected in novae explosions. By the time of the second epoch observations, the emission lines of the neutral C, N, and O had disappeared. He i 10830 was the dominant emission feature in the spectrum. In addition to the hydrogen lines, recombination features of He ii were also strong. The common nebular lines of [S iii] were seen but only two coronal line, [S viii] 9911 and [Si vi] 19645, were detected. The CO emission had disappeared, but a strong thermal dust component was present. The interstellar reddening for the system was found to be E(BÀV Þ ¼ 1:3. This extinction, together with the absolute magnitude derived from the rate of decline of the light curve, suggest a distance of $10.8 kpc. This places V2274 Cyg well out of the Galactic plane. The small number of novae with spectroscopic detections of carbon monoxide all have prominent C i lines, moderate speed classes and ejection velocities, exhibit marked dust formation events, and result from an explosion on a CO-type white dwarf. Based on these similarities, the spectrum of V2274 is proposed as a likely near-infrared spectral template for other novae that display carbon monoxide emission.

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“…This is true for all features except that at 1.1110 m. In V723 Cas, that feature appeared to resolve into two features, at approximately 1.1107 and 1.1132 m, respectively. These unidentified novae lines (UNL) have been seen in several other novae (e.g., Lynch et al 2001), and they are rarely, if ever, present during the early, low-excitation stage. They first appear about the same time as the He ii lines but usually before any of the coronal lines become evident.…”

Section: Time Evolution Of the Spectramentioning

confidence: 89%

“…Although the age and speed class of the novae shown here vary, all are in the early to intermediate excitation stage. Venturini et al 2000;Rudy et al 2001), andV4633 Sgr (=Nova Sgr 1998;Lynch et al 2001). In Figure 10, we show all four spectra.…”

Section: Reddening and Distancementioning

confidence: 99%

Time Development of Recurrent Nova CI Aquilae's 2000 Outburst between 0.8 and 2.5 MICRONS

Lynch¹,

Wilson²,

Rudy³

et al. 2004

Astron J

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We report 0.8-2.5 m spectrophotometry of CI Aquilae at eight epochs between 2000 May 9 and 2001 June 2 UT, corresponding to approximately 3 and 391 days after peak brightness. Near peak brightness, the spectra showed emission lines that were characteristic of a low-excitation, nitrogen-rich shell. Within a few weeks, the spectra began to show higher excitation/ionization emission lines indicative of a harder illuminating source: the neutral metal lines faded, leaving only lines of H i, He i, and He ii and the emerging coronal lines. A month after peak brightness, the [Ca viii] coronal line at 2.3205 m appeared and persisted until the last of our observations, on day +391. From the O i line ratios, we deduced a reddening of E BÀV = 1.5 AE 0.1 and a visual extinction of A V = 4.6 AE 0.2. Along with the rate of decline from the light curve (t 2 ), we derived a distance of 2.6 AE 1.3 kpc. The frequently observed unidentified novae lines were present in CI Aquilae along with a potentially new member of the group at 2.425 AE 0.002 m.

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The Late Appearance of Heiin V445 Puppis

Cited by 17 publications

References 6 publications

NOVA V2362 CYGNI (NOVA CYGNI 2006):SPITZER,SWIFT, AND GROUND-BASED SPECTRAL EVOLUTION

NOVA V2362 CYGNI (NOVA CYGNI 2006):SPITZER,SWIFT, AND GROUND-BASED SPECTRAL EVOLUTION

Near‐Infrared Spectrophotometry and the CO Emission in V2274 Cygni (Nova Cygni 2001 No. 1)

Time Development of Recurrent Nova CI Aquilae's 2000 Outburst between 0.8 and 2.5 MICRONS

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