J/ApJ/939/113 UVES and FEROS sp. of HD 80077 and HD 166734 (Krelowski+, 2022)
Presumed detection of C5 molecule in the interstellar medium.
Krelowski J., Hakalla R., Szajna W.
<Astrophys. J., 939, 113 (2022)>
=2022ApJ...939..113K 2022ApJ...939..113K
ADC_Keywords: Spectra, optical; Stars, giant; Molecular data;
Interstellar medium
Keywords: Interstellar medium ; Interstellar absorption ; Interstellar molecules
Abstract:
The paper suggests the presence of the carbon chain C5 molecule in
translucent, interstellar HI clouds. This species, the only five atom
interstellar molecule, observable in dark, translucent clouds, seems
to be observable in reasonably dense clouds, causing also rather high
reddening. The paper shows two likely discovered spectral features of
C5, A1Πu-X1Σg+ bands near 4975 and 5109Å. The
attempt to discover the 3789Å C4 feature gave the negative result.
Description:
Our observational data have been collected using two high-resolution,
echelle spectrographs:
1. Ultraviolet and visual echelle spectrograph (UVES) fed by the 8m
Kueyen Very Large Telescope (VLT) mirror. The spectral resolution
(R=λ/Δλ) is up to 80000 in the blue range and
110000 in the red one. The spectral range (3040-10400Å) is usually
divided into six subranges. The telescope size allows to get high S/N
spectra of even pretty faint stars. The star HD 80077 was observed
using this instrument.
2. FEROS spectrograph, which is fed by the 2.2m ESO LaSilla telescope.
It allows to record in a single exposure the spectral range from 3600
to 9200Å, divided into 39 echelle orders. The resolution of Feros
spectra is R=48000. The spectrum of HD 166734 were recorded using this
instrument.
Figure 2 demonstrates the spectra of both targets, covering the ranges
of the two expected C5, A1Πu-X1Σg+ features: 4975
and 5109Å.
Objects:
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RA (ICRS) DE Designation(s)
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09 15 54.78 -49 58 24.5 HD 80077 = V* PV Vel
18 12 24.65 -10 43 53.0 HD 166734 = V* V411 Ser
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 35 11824 Observed spectra of both considered targets
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See also:
Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 0.1nm lam1 Wavelength, HD 80077, Figure 2, blue line (1)
11- 17 F7.5 --- I1 Relative intensity, HD 80077 (1)
19- 27 F9.4 0.1nm lam2 ? Wavelength, HD 166734, Figure 2, red line (2)
29- 35 F7.5 --- I2 ? Relative intensity, HD 166734 (2)
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Note (1): Notes on HD 80077 observation -- uves122 observation taken on
2014-03-10 under ESO program ID = 092.C-0019(A)
Note (2): Notes on HD 166734 observation -- FEROS observation taken on
2004-05-09 under ESO program ID = 073.D-0609(A)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Sep-2024