J/A+AS/116/95 Magellanic Clouds PNe line intensities (Leisy+, 1996)
Planetary nebulae in the Magellanic Clouds : I. Carbon abundances and TypeI PNe
Leisy P., Dennefeld M.
<Astron. Astrophys. Suppl. Ser. 116, 95 (1996)>
=1996A&AS..116...95L 1996A&AS..116...95L (SIMBAD/NED BibCode)
ADC_Keywords: Planetary nebulae ; Spectroscopy ; Magellanic Clouds
Keywords: ISM: planetary nebulae : general - galaxies: Magellanic Clouds -
galaxies: abundances - galaxies: evolution
Description:
We present optical and ultraviolet spectroscopic observations of
planetary nebulae (PNe) in the Large (LMC) and the Small Magellanic
Clouds (SMC). For the visible spectra with highest S/N, line
intensities have been measured to a few tenths of a percent of
Hβ. UV spectra are used for the determination of carbon
abundances. This paper discusses the CNO cycle and its implications.
We show that the CN or ON cycles are more effective with lower initial
metallicities and are always complete for typeI nebulae. The latter
cannot easily be distinguished from non-type I PNe on the basis of N
or He abundance alone, as continuity exists in all of the standard
diagrams. From the study of the C abundances, we deduce that the 3rd
dredge-up is occurring in all PNe: its efficiency too is higher with
lower initial metallicities, offering an easy explanation for the
higher number of carbon stars found in metal-deficient galaxies. It
is shown that this dredged-up carbon is sometimes transformed into
nitrogen by Hot-Bottom Burning, but in a few objects only and not even
in all the typeI PNe, which therefore do not form a homogeneous class.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table7 61 960 SMC PNe observed and corrected line intensities
table8 65 1019 LMC PNe observed and corrected line intensities
table78a 77 31 Flux, electronic density and temperature
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Byte-by-byte Description of file: table7 table8
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Planetary nebulae name
10- 14 I5 --- Lambda Wavelength
19- 33 A15 --- Ident Line identification
37- 42 F6.3 --- Flambda Extinction curve value for Lambda
44 A1 --- l_Fobs Limit flag on Fobs
45- 50 F6.1 --- Fobs []? Observed line intensity (1)
51 A1 --- u_Fobs Uncertainty flag on Fobs
53 A1 --- l_Fcor Limit flag on Fcor
54- 60 F7.1 --- Fcor []? Corrected line intensity (1)
61 A1 --- u_Fcor Uncertainty flag on Fcor
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Note (1): scale F(Hbeta)=100
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Byte-by-byte Description of file: table78a
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Planetary nebula name
10 A1 --- l_Fb Limit flag on Fb
11- 14 I4 10-16mW/m2 Fb Flux Hbeta (10-16 erg/cm2/s-1)
17- 20 F4.1 % e_Fb Hbeta uncertainty
24- 28 I5 --- Exp1 IUE exposure number (first number)
32- 36 I5 --- Exp2 []? IUE exposure number (second number)
39- 43 I5 --- Exp3 []? IUE exposure number (third number)
46- 50 I5 cm-3 Ne Electronic density
53- 57 I5 K T(OIII) ? [OIII] electronic temperature
60- 64 I5 K T(NII) ? [NII] electronic temperature
67- 70 F4.2 --- Copt Logarithmic extinction constant
72- 75 F4.2 --- e_Copt rms uncertainty on Copt
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Courtesy: P. Leisy
(End) Patricia Bauer [CDS] 09-Jan-1996