scholarly journals HST/WFPC2 imaging analysis and cloudy modelling of the multiple-shell planetary nebulae NGC 3242, NGC 6826, and NGC 7662

2018 ◽  
Vol 480 (2) ◽  
pp. 1626-1638 ◽  
Author(s):  
D Barría ◽  
S Kimeswenger
Keyword(s):  
Planetary Nebulae ◽  
Imaging Analysis ◽  
Ngc 7662

scholarly journals Ultraviolet spectra of planetary nebulae - VI. NGC 7662

1982 ◽  
Vol 199 (3) ◽  
pp. 517-564 ◽  
Author(s):  
J. P. Harrington ◽  
M. J. Seaton ◽  
S. Adams ◽  
J. H. Lutz
Keyword(s):  
Planetary Nebulae ◽  
Ultraviolet Spectra ◽  
Ngc 7662

High dispersion spectra of Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 242-242
Author(s):  
S. Hyung ◽  
L. H. Aller
Keyword(s):  
Plasma Diagnostics ◽  
Surface Brightness ◽  
High Surface ◽  
Planetary Nebulae ◽  
High Dispersion ◽  
Chemical Compositions ◽  
Echelle Spectrograph ◽  
High Surface Brightness ◽  
Low Surface Brightness ◽  
Ngc 7662

Determinations of the plasma diagnostics and chemical compositions of planetary nebulae require ultimately high dispersion spectra. For objects of high surface brightness the Hamilton Echelle Spectrograph at Lick Observatory is satisfactory for the region 3650–10100Å which involves the 168th to 56th echelle orders. For a slit width of 640 μm amounting to 1.15 arcsec at the Coude focus, the actual spectral resolution (FWHM) is about 0.2Å at 8850Å. The length of the slit is chosen as 4.0 arcsec. Hyung (1994) & Aller (1994) describe the observing procedure. Since the Hamilton echelle was designed primarily for star-like sources, it is not useful for extended low surface brightness PN. The earlier observations were obtained with an 800 × 800 chip that did not cover the echelle field, so several settings were needed. Later, we used a slower 2048 × 2048 chip which covered the whole field and was somewhat more efficient at longer wavelengths. The program has been completed and definitive measurements have obtained for NGC 2440, NGC 6543, NGC 6741, NGC 6818, NGC 7026, NGC 7662, and Hu 1-2. All of these PN display particularly rich, interesting spectra. Previously observed and published objects include IC 351, IC 418, IC 2149, IC 4997, NGC 6567, NGC 6572, NGC 6790, NGC 6886, NGC 7009, BD +30 3639, & Hubble 12. NGC 6884 is in press. Additional nebulae which are yet to be discussed are IC 4634, IC 4846, IC 5117, NGC 6210, & NGC 6803.

scholarly journals Infrared Images and Line Profiles of Planetary Nebulae

1989 ◽  
Vol 131 ◽  
pp. 178-178
Author(s):  
M. G. Smith ◽  
T. R. Geballe ◽  
C. Aspin ◽  
I. S. Mclean ◽  
P. F. Roche
Keyword(s):  
Planetary Nebulae ◽  
Line Profiles ◽  
Infrared Images ◽  
Infrared Telescope ◽  
The United Kingdom ◽  
Fabry Perot ◽  
Ngc 7027 ◽  
Ngc 7662 ◽  
Infrared Array ◽  
Selection Of

We present high spatial resolution infrared images of the planetary nebulae NGC 7027, M2-9, BD +30 3639, NGC 7099 and NGC 7662. These were taken through a selection of broad and narrow-band line and continuum filters (including a Fabry-Pérot interferometer) using the 2D infrared array “IRCAM” on the United Kingdom Infrared Telescope, UKIRT, in July 1987. Comparison is made with recently published high-resolution VLA radio maps (Basart and Daub 1987, Ap. J., 317, 412) and mid-IR Wyoming Infrared Telescope raster-scanning maps (Bentley et al.1984, Ap. J., 278, 665).

scholarly journals Spectroscopy and Photoionization Model of Planetary Nebulae: NGC 6543 and NGC 7662

2016 ◽  
Vol 771 ◽  
pp. 012030
Author(s):  
Evaria Puspitaningrum ◽  
Hakim Lutfi Malasan ◽  
Hideyo Kawakita
Keyword(s):  
Planetary Nebulae ◽  
Ngc 7662 ◽  
Photoionization Model

scholarly journals Abundances of planetary nebulae NGC 7662 and NGC 6741

2001 ◽  
Vol 380 (2) ◽  
pp. 684-694 ◽  
Author(s):  
S. R. Pottasch ◽  
D. A. Beintema ◽  
J. Bernard Salas ◽  
W. A. Feibelman
Keyword(s):  
Planetary Nebulae ◽  
Ngc 7662

scholarly journals On the Variability of the Nuclei of Three Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 381-382
Author(s):  
M.A. Kazarian
Keyword(s):  
Preliminary Data ◽  
Planetary Nebulae ◽  
Schmidt Telescope ◽  
Objective Prism ◽  
Extensive Program ◽  
Ngc 7662

The observations of nuclei of three planetary nebulae, NGC 6826, NGC 7662 and IC 4593, have been made as part of a more extensive program with the aim of obtaining their absolute spectrophotometric gradients (ϕ) and photographic magnitudes (from the spectrogram). The spectra were obtained with an 8–12′ Schmidt telescope combined with an objective prism (the dispersion is 420 Å/mm at Hγ). The preliminary data which were obtained at different times, particularly the spectrophotometric gradients of the nuclei of these nebulae, did not agree with each other.

scholarly journals Accurate Abundances Determination of Planetary Nebulae

2003 ◽  
Vol 209 ◽  
pp. 376-376
Author(s):  
J. Bernard Salas ◽  
S. R. Pottasch ◽  
P. R. Wesselius ◽  
P. Marigo
Keyword(s):  
Planetary Nebulae ◽  
Central Star ◽  
Optical Data ◽  
Infrared Space Observatory ◽  
Chemical Abundances ◽  
Mixing Processes ◽  
International Ultraviolet Explorer ◽  
Ngc 7027 ◽  
Ngc 7662 ◽  
Using Data

Accurate chemical abundances for the following planetary nebulae (PNe); NGC 6537, He 2-111, NGC 6302, NGC 6445, NGC 6741, NGC 7027, NGC 7662, NGC 2440 and NGC 5315 have been derived using data from the Infrared Space Observatory (ISO) and the International Ultraviolet Explorer (IUE). Optical data from the literature has also been used. These work has been published by Pottasch et al. (2001), Bernard Salas et al. (2001 and 2002). In particular, the use of the ISO data has reduced the need for ionization correction factors. Furthermore, infrared data avoid or reduce many problems when deriving these abundances, namely: temperature fluctuations in the nebula, and extinction corrections. The electron temperature (Te) and density of the PNe has been derived. For those PNe in which the Te has been derived for several ions a trend with the ionization potential is present. Ions with high stages of ionization give higher Te, probably because they are formed close to the central star. The chemical abundances measured in these PNe give some hint of the nucleosynthesis and mixing processes experienced by their progenitor stars. In this view, a preliminary comparison with synthetic TP-AGB models is made (Bernard Salas et al. (in prep.)). NGC 7027, NGC 6741, NGC 2440, and NGC 6445 are consistent with the occurrence of the 3rd dredge-up due to both C12 and He4 enrichment. NGC 6537, NGC 6302, and He 2-111 are likely to have stellar progenitors experiencing hot bottom burning due to the low C12 and high N14 abundances.

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