J/AJ/121/362 Near-Infrared Spectra of IC5117 (Rudy+, 2001)
The near-infrared spectrum of the planetary nebula IC 5117.
Rudy R.J., Lynch D.K., Mazuk S., Puetter R.C., Dearborn D.S.P.
<Astron. J., 121, 362-370 (2001)>
=2001AJ....121..362R 2001AJ....121..362R
ADC_Keywords: Planetary nebulae ; Spectra, infrared
Keywords: Infrared Radiation, ISM: Planetary Nebulae:
Individual: Alphanumeric: IC5117
Abstract:
Infrared spectroscopy from 0.8 to 2.5µm is presented for the
planetary nebula IC5117. The emission lines of IC5117 span a wide
range of ionization that includes He II, [S III], [S II], [N I], and
H2. The reddening measured from the hydrogen lines is E(B-V)=0.79,
most of which is probably interstellar in origin. The He/H abundance
ratio is 0.113±0.015, with approximately 10% of the helium being
doubly ionized. Using our measurements of [S II] and [S III] lines and
published observations of [S IV], we find a sulfur abundance, relative
to hydrogen, of N(S)/N(H)=7.8 x 10-6, or approximately half the
solar value. Fluxes and flux limits for several lines of molecular
hydrogen are presented. Measurements of 1-0 transitions, together with
the limits on 2-1 transitions, indicate Tvib∼Trot=1900K, suggesting a
purely collisional excitation mechanism. The ortho-to-para ratio is
∼3, a value that is also indicative of collisional excitation. The
presence of [C I] λ9850 is consistent with previous studies of
IC 5117 that indicated carbon is more abundant than oxygen. IC5117
follows the trend of planetary nebulae that display bipolar outflows
and H2 emission to be carbon-rich. We confirm the results of Zhang &
Kwok, who reported infrared continuum emission substantially in excess
of that produced by the ionized gas. This emission is most likely due
to hot dust (T∼1300K) and accounts for roughly half of the continuum
between 1.5 and 2µm.
Description:
The infrared spectrophotometry of IC 5117 was acquired on the night of
1999 August 30 (UT) with the 3m Shane reflector of Lick Observatory
and its Aerospace Near-Infrared Imaging Spectrograph.
Objects:
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RA (2000) DE Designation(s)
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21 32 30.9 +44 35 48 IC 5117 = HD 205211
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 74 Observed emission-line strengths of IC 5117
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Line Line identification
15- 19 I5 0.1nm lambda [8046/24231] Wavelength λ (Å) (1)
21- 25 I5 0.1nm Olambda ? Wavelegth of nearby line with same line ID (1)
27- 32 F6.4 --- Ratio [0.002/7.6]? Flux ratio relative to Paβ (2)
34- 39 F6.4 --- e_Ratio [0.0008/0.4]? Uncertainty in Ratio
41- 50 A10 --- f_Ratio "Atmosphere" Indicates an atmospheric line
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Note (1): Laboratory wavelengths as measured in air.
Note (2): Flux of Paβ is 4.95-12ergs/cm2/s.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Laurent Cambresy [CDS] 18-Aug-2004