J/A+A/585/A112 IRAS 16293-2422 spectrum (Martin-Domenech+, 2016)
The sulfur depletion problem: upper limits on H2S2, HS2, and S2
abundances toward IRAS 16293-2422.
Martin-Domenech R., Jimenez-Serra I., Munoz Caro G.M., Muller H.S.P.,
Occhiogrosso A., Testi L., Woods P., Viti S.
<Astron. Astrophys. 585, A112 (2016)>
=2016A&A...585A.112M 2016A&A...585A.112M (SIMBAD/NED BibCode)
ADC_Keywords: Infrared sources ; Radio lines ; Spectroscopy
Keywords: ISM: abundances - ISM: molecules -
ISM: individual objects: hot corino - methods: observational -
radio lines: ISM
Abstract:
A fraction of the missing sulfur in dense clouds and circumstellar
regions could be in the form of three species not yet detected in the
interstellar medium: H2S2, HS2, and S2 according to experimental
simulations performed under astrophysically relevant conditions. These
S-S bonded molecules can be formed by the energetic processing of
H2S-bearing ice mantles on dust grains, and subsequently desorb to the
gas phase.
The detection of these species could partially solve the sulfur
depletion problem, and would help to improve our knowledge of the
poorly known chemistry of sulfur in the interstellar medium. To this
purpose we calculated the frequencies and expected intensities of the
rotational transitions not previously reported, and performed
dedicated ground-based observations toward the low-mass warm core
IRAS 16293-2422, a region with one of the highest measured gas-phase
H2S abundances.
Observations in the submillimeter regime were obtained with the APEX
12m telescope during 15h of observation. A total of ∼16GHz were
covered in a range of about 100GHz, targeting a wide selection of the
predicted rotational transitions of the three molecules.
Description:
Tables 6_5.dat, 8_7.dat, 10_9.dat, and 14_13.dat correspond to the
sub-mm spectra in ascii format observed toward the low-mass warm core
IRAS16293-2422 in the spectral regions between 221.5GHz and 225.5GHz,
224.4GHz and 253.4GHz, 277.0GHz and 281.0GHz, and 333.0GHz and
337.0GHz, respectively. The observations were carried out with the
APEX 12m telescope under pwv conditions between 1.1mm and 2.2mm, using
the SHeFI instruments APEX-1 and APEX-2 as frontends and the XFFTS
spectrometer as backend, at a resolution of 80KHz. The
position-switching mode was chosen to perform the on/off observations.
The on position was centered toward IRAS16293-2422 A.
Objects:
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RA (2000) DE Designation(s)
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16 32 22.56 -24 28 31.8 IRAS 16293-2422 = NAME IRAS 1629A
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
6_5.dat 29 52429 Spectrum in 221.5-225.5GHZ spectral region
8_7.dat 29 52381 Spectrum in 249.4-253.4GHZ spectral region
10_9.dat 29 52429 Spectrum in 277.0-281.0GHZ spectral region
14_13.dat 29 52429 Spectrum in 333.0-337.0GHZ spectral region
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Byte-by-byte Description of file: 10_9.dat 14_13.dat 6_5.dat 8_7.dat
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Bytes Format Units Label Explanations
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4- 13 F10.3 MHz Freq Frequency
19- 29 E11.5 K Ta Antenna temperature
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Acknowledgements:
Rafael Martin-Domenech, rmartin(at)cab.inta-csic.es
(End) R. Martin-Domenech [CAB (INTA-CSIC)], P. Vannier [CDS] 24-Nov-2015