J/A+A/404/545 Optical spectrum of M 2-24 (Zhang+ 2003)
Optical spectrum of the planetary nebula M 2-24.
Zhang Y., Liu X.-W.
<Astron. Astrophys. 404, 545 (2003)>
=2003A&A...404..545Z 2003A&A...404..545Z
ADC_Keywords: Planetary nebulae ; Spectroscopy
Keywords: ISM: abundances - planetary nebulae: individual: M 2-24 -
ISM: lines and bands
Abstract:
We have obtained medium-resolution, deep optical long-slit spectra of
the bulge planetary nebula (PN) M 2-24. The spectrum covers the
wavelength range from 3610-7330Å. Over two hundred emission lines
have been detected. The spectra show a variety of optical
recombination lines (ORLs) from C, N, O and Ne ions. The diagnostic
diagram shows significant density and temperature variations across
the nebula. Our analysis suggests that the nebula has a dense central
emission core. The nebula was thus studied by dividing it into two
regions: 1) an high ionization region characterized by an electron
temperature of Te=16300K and a density of logNe(cm-3)=6.3; and
2) a low ionization region represented by Te=11400K and
logNe(cm-3)=3.7. A large number of ORLs from C, N, O and Ne ions
have been used to determine the abundances of these elements relative
to hydrogen. In general, the resultant abundances are found to be
higher than the corresponding values deduced from collisionally
excited lines (CELs). This bulge PN is found to have large
enhancements in two α-elements, magnesium and neon.
Description:
This is a full list of observed lines of M 2-24 and their measured
fluxes. Observations were carried out with the ESO 1.52m telescope
using the long-slit spectrograph Boller & Chivens. The spectrum covers
the wavelength range from 3610-7330Å.
Objects:
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RA (2000) DE Designation(s)
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18 02 04.1 -34 27 47 M 2-24
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spectrum.dat 80 207 Observed relative line fluxes, on a scale
where Hβ=100
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Byte-by-byte Description of file: spectrum.dat
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Bytes Format Units Label Explanations
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2- 8 F7.2 0.1nm LambdaObs ? The observed wavelength
11- 17 F7.3 --- F(Lambda) ? The observed flux (1)
18 A1 --- u_F(Lambda) [:*] ":" for uncertain value
19 A1 --- f_F(Lambda) [a-z A-L] Blended lines (same letter for
lines blended together
21- 27 F7.3 --- I(Lambda) ? The dereddened flux (1)
28 A1 --- n_I(Lambda) [a-z A-L] Blended lines
30- 37 A8 --- Ion The ionic identification
40- 46 F7.2 0.1nm LambdaLab The laboratory wavelength
48- 52 A5 --- Mult The multiplet number
57- 63 A7 --- LowerTerm The lower spectral terms of the transition
66- 73 A8 --- UpperTerm The upper spectral terms of the transition
75- 76 I2 --- g1 The statistical weight of the lower level
78- 79 I2 --- g2 ? The statistical weight of the upper level
80 A1 --- n_g2 [*] *: blended lines, no value in g2
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Note (1): All fluxes are normalized such that Hβ=100.
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Acknowledgements: Yong Zhang
(End) Y. Zhang [NAO, China] 01-Apr-2003