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Salama, A.; Barr, P.; Clavel, J.; Jenkins, R. N.; Leech, K.; Kessler, M. F.; Lim, Taeho; Metcalfe, L.; Schulz, B.; Evans, A.; Eyres, S. P. S.

doi:10.1023/a:1001150716412

Cited by 8 publications

(13 citation statements)

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“…The Oxygen abundance was reduced from 110 to 80 to get a better fit for [O III] λλ4959/5007. We therefore increase the Ne/O ratio from 2.3 (A96) to 3.1, in closer agreement with the value of Ne/O=4 found by Salama et al (1996). The N/O ratio gives a value of 0.6, which is consistent with a white dwarf's mass between 1.25 M ⊙ and 1.35 M ⊙ (Starrfield et al 1992).…”

Section: Abundancessupporting

confidence: 88%

The Optical Spectroscopic Evolution of V1974 Cygni (Nova Cygni 1992)

Moro‐Martín¹,

Garnavich

Noriega-Crespo

2001

The Astronomical Journal

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Optical observations of nova V1974 Cygni (Cygni 1992), spanning a 4 year period, have been used to study its spectroscopic evolution. The data cover a wavelength range from $\sim 3200 - 8000$ \AA and follows the nebular evolutionary phase of the ejecta. We have modeled the integrated fluxes by means of the photoionization code CLOUDY. The models were run at a {\it fixed} abundance value for the most prominent elements (i.e. H, He, C, O, N, Ne, Fe, etc) over the entire time sequence. It is possible to constrain from this simple model some of the physical conditions of the gaseous emitting region, like temperature and density. Compared with previous studies of the gas abundances of the heavy elements, we found that smaller enhancements of S, N and Ar, and comparable values for O and Fe, are able to reproduce the observations. The time evolution of the surface temperature of the ionizing source and the high-ionization iron lines [Fe VII] 6087 \AA and [Fe X] 6374 \AA, is similar to what it is observed in the soft X-rays. The early line profiles can be reproduced using a simple kinematical model consisting of an equatorial ring and polar caps, expanding at a velocity of $\sim 1100$ km/s. This simple model also approximates the structure of the resolved shell observed by HST. Considering the complicated structure of the shell, the lack of well defined values of its gas density and our limited knowledge of the time evolution of the surface temperature of the photoionization source, the comparison between models and observations agrees remarkably well.Comment: 14 text pages, 12 figure

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Section: Abundancessupporting

confidence: 88%

The Optical Spectroscopic Evolution of V1974 Cygni (Nova Cygni 1992)

Moro‐Martín¹,

Garnavich

Noriega-Crespo

2001

The Astronomical Journal

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“…It is worth noting that, in contrast to the nova V1974 Cyg (1992), which continued to show a rich far‐IR emission‐line spectrum in the ISO range some 2000 d after eruption (Salama et al 1996 and work in preparation), V705 Cas ‐‐ at ∼1000 d after the outburst ‐‐ shows a weak far‐IR spectrum. This is consistent with our near‐IR observations (Eyres et al, in prepration), which suggest that the near‐IR emission lines had become very weak by day 945.…”

Section: Resultsmentioning

confidence: 99%

Infrared spectroscopy of Nova Cassiopeiae 1993 -- III. ISO observations

Salama

Eyres

Evans

et al. 1999

Monthly Notices of the Royal Astronomical Society

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The [Oiv]λ25.89 fine‐structure line has been detected in Nova Cassiopeiae 1993 (V705 Cas) by the Short Wavelength Spectrometer on the Infrared Space Observatory (ISO). Preliminary analysis using cloudy suggests that oxygen is overabundant relative to solar by at least 25 (by number), and that the abundance of neon is 0.5 × solar at most; the hydrogen density at the time of the ISO observation is in the range 104.1≲ nH(cm‐3) ≲ 104.65. The dust shell, which was prominent in the near infrared in earlier ground‐based observations, was not detected by the ISO.

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“…Salama et al (1996) reported SWS and LWS observations of Nova V1974 Cyg 1992, obtained 1494 days after the outburst. From measured FS line flux ratios, they estimated electron temperatures in the ejecta and derived an enhanced Ne/O ratio of ∼4.…”

Section: Observations Of Novaementioning

confidence: 99%

“…From measured FS line flux ratios, they estimated electron temperatures in the ejecta and derived an enhanced Ne/O ratio of ∼4. Salama et al (1997) presented further ISO SWS observations of Nova V1974 Cyg 1992, including detailed line profiles of the [Ne V] 14.32 and 24.32 µm lines at four different epochs. The density sensitive [Ne V] line ratio was found to decrease with time t as t −3 , in accord with ejecta expansion expectations.…”

Section: Observations Of Novaementioning

confidence: 99%

“…The density sensitive [Ne V] line ratio was found to decrease with time t as t −3 , in accord with ejecta expansion expectations. Salama et al (1997) also presented ISO spectra of Nova HR Del 1967 and Nova V705 Cas 1993. Further ISO observations of the latter nova, obtained between 950 and 1455 days after outburst, were presented by Salama et al (1999).…”

Section: Observations Of Novaementioning

confidence: 99%

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Late Stages of Stellar Evolution

et al. 2005

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A large fraction of ISO observing time was used to study the late stages of stellar evolution. Many molecular and solid state features, including crystalline silicates and the rotational lines of water vapour, were detected for the first time in the spectra of (post-)Asymptotic Giant Branch (AGB) stars. Their analysis has greatly improved our knowledge of stellar atmospheres and circumstellar environments. A surprising number of objects, particularly young planetary nebulae with Wolf-Rayet (WR) central stars, were found to exhibit emission features in their ISO spectra that are characteristic of both oxygen-rich and carbon-rich dust species, while far-IR observations of the PDR around NGC 7027 led to the first detections of the rotational line spectra of CH and CH + .

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Cited by 8 publications

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The Optical Spectroscopic Evolution of V1974 Cygni (Nova Cygni 1992)

The Optical Spectroscopic Evolution of V1974 Cygni (Nova Cygni 1992)

Infrared spectroscopy of Nova Cassiopeiae 1993 -- III. ISO observations

Late Stages of Stellar Evolution

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