J/ApJ/851/L46 CH3OCH2OH ALMA detection in NGC 6334I (McGuire+, 2017)
ALMA detection of interstellar methoxymethanol (CH3OCH2OH).
McGuire B.A., Shingledecker C.N., Willis E.R., Burkhardt A.M., El-Abd S.,
Motiyenko R.A., Brogan C.L., Hunter T.R., Margules L., Guillemin J.-C.,
Garrod R.T., Herbst E., Remijan A.J.
<Astrophys. J., 851, L46 (2017)>
=2017ApJ...851L..46M 2017ApJ...851L..46M
ADC_Keywords: Atomic physics; Interstellar medium; Molecular data;
Spectra, millimetric/submm
Keywords: astrochemistry ; ISM: individual objects (NGC 6334I) ; ISM: molecules
Abstract:
We report the detection of interstellar methoxymethanol
(CH3OCH2OH) in Atacama Large Millimeter/submillimeter Array (ALMA)
Bands 6 and 7 toward the MM1 core in the high-mass star-forming region
NGC 6334I at ∼0.1-1" spatial resolution. A column density of
4(2)x1018cm-2 at Tex=200K is derived toward MM1, ∼34 times less
abundant than methanol (CH3OH), and significantly higher than
predicted by astrochemical models. Probable formation and destruction
pathways are discussed, primarily through the reaction of the CH3OH
photodissociation products, the methoxy (CH3O) and hydroxymethyl
(CH2OH) radicals. Finally, we comment on the implications of these
mechanisms on gas-phase versus grain-surface routes operative in the
region, and the possibility of electron-induced dissociation of CH3OH
rather than photodissociation.
Description:
We present detections of the CH3OCH2OH molecule in four ALMA data
sets: 2017 Aug 18,19 in Band 6 (249GHz) with a spectral resolution of
0.6km/s, 2016 Jul 18 & Aug 02 in Band 7 (287GHz) with a spectral
resolution of 1.1kms, 2016 Jan 17 in Band 7 (303GHz) with a spectral
resolution of 1.0km/s and 2016 Jul 17 & Aug 02 in Band 7 (344GHz) with
a spectral resolution of 1.1km/s.
Objects:
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RA (ICRS) DE Designation(s)
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17 20 53.35 -35 47 01.5 NGC 6334I = NAME NGC 6334-I
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 48 1474 Line parameters of CH3OCH2OH
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See also:
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/A+A/601/A49 : CH3NHCHO rotational spectroscopy (Belloche+, 2017)
J/A+A/605/L3 : SOLIS. I. L1157-B1 NH2CHO image (Codella+, 2017)
J/ApJ/835/46 : methoxy radical (CH3O) rotational spectrum (Laas+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- QN Quantum numbers
25- 35 F11.4 MHz Freq [239256/351903] Frequency (MHz)
37- 40 F4.2 D2 Siju2 [0/2] Strength (Debye2)
42- 48 F7.2 K Eu [31.6/1883] Upper energy (K)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Jul-2018