J/PAZh/26/510 Spectrum of bipolar nebula AFGL 2688 (Klochkova+, 2000)
Optical spectrum of the bipolar nebula AFGL 2688.
Klochkova V.G., Szczerba R., Panchuk V.E.
<Pis'ma Astron. Zh. 26, 510 (2000)>
=2000PAZh...26..510K 2000PAZh...26..510K
=2000AstL...26..439K 2000AstL...26..439K
ADC_Keywords: Nebulae ; Spectrophotometry ; Equivalent widths ; Abundances
Abstract:
Based on echelle spectra obtained at the prime focus of the 6-m
telescope, the detailed chemical composition of one of the components
of the bipolar nebula identified with the intense infrared source AFGL
2688 was determined by the model-atmosphere method.
Objects:
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RA (2000) DE Designation(s)
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21 02 18.8 +36 41 38 RAFGL 2688 = V1610 Cyg = Egg Nebula
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 41 197 Atomic data, equivalent widths of special lines
and chemical composition
table3.dat 56 26 Chemical composition log(eps(X)) of AFGL 2688
(for log(eps(H))= 12.0).
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See also:
J/PAZh/26/465 : IRAS 20004+2955 (V1027 Cyg) chemical comp. (Klochkova+, 2000)
J/PAZh/26/115 : Spectrum of IRAS 23304+6147 (Klochkova+, 2000)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm Lambda Wavelength
10- 13 A4 --- El Element
16- 20 F5.2 eV ExcPot Excitation potential of the lower level
23- 27 F5.2 --- Loggf Oscillator strength (log gf)
30- 32 I3 0.1pm EW Equivalent width in milli(Angstroem)
33 A1 --- n_EW [*] Lines unused to determine the mean
element abundance
36- 41 F6.2 --- A(X) Chemical composition (1)
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Note (1):
At hydrogen abundance A(H)=0, with model parameters Teff=6500K,
logg=0.0 and ξ(t)=6.0km/s
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- XSun Element
7- 10 F4.2 --- log(XSun) Sun elemental abundance (1)
19- 22 A4 --- X Ion
28- 31 F4.2 --- log(X) AFGL 2688 abundance for the ion
38- 41 F4.2 --- e_log(X) ? Error in the mean abundance derived for a
given number of lines
45- 46 I2 --- Nline Number of lines used
52- 56 F5.2 Sun [X/Fe] Relative abundance (2)
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Note (1): The elemental abundances in the solar photosphere were taken from
Grevesse et al, 1996, ASP Conf. 99, 117; for lithium its meteoritic
abundance was used
Note (2): [X/Fe] = [log(X)-log(Fe)]* - [log(X)-log(Fe)]☉
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(End) Veta Avedisova [INASAN] 02-May-2000