J/ApJS/266/29 IRAM 3mm, 2mm & 1.3mm obs. of star-forming regions (Zhao+, 2023)
A multitransition methanol survey toward a large sample of high-mass
star-forming regions.
Zhao J.Y., Zhang J.S., Wang Y.X., Qiu J.J., Yan Y.T., Yu H.Z., Chen J.L.,
Zou Y.P.
<Astrophys. J. Suppl. Ser., 266, 29 (2023)>
=2023ApJS..266...29Z 2023ApJS..266...29Z
ADC_Keywords: Star Forming Region; Spectra, millimetric/submm; Masers;
Space velocities; Molecular data; Abundances; Interstellar medium
Keywords: Interstellar molecules ; Astrochemistry ; Molecule formation
Abstract:
We carried out a spectral line survey of CH3OH toward a large sample
of 175 high-mass star-forming regions in the 3mm, 2mm, and 1.3mm bands
with the Institut de Radioastronomie Millimetrique (IRAM) 30m
telescope. Out of our 175 targets, 148 sources were detected with one
or more CH3OH transition lines. Nineteen CH3OH transition lines,
including 13 thermal lines and 6 maser lines, were detected. The
80->71 A+ (∼95.169GHz) CH3OH maser line, one of the strongest
class I CH3OH maser lines, was detected in 52 sources. Forty-two of
them are previously reported masers and the other 10 are new
detections. Through analyzing the rotational diagram of the detected
CH3OH emission lines (nonmasing lines), we obtained the rotational
temperature and the column density for 111 sources. Our results show
that E-type CH3OH tends to have lower column density than A-type
CH3OH. The column density ratio of E/A was derived in 55 sources
with the majority having a ratio less than 1.0 (about 70%), with a
peak ratio of ∼0.6. This is consistent with theoretical predictions,
i.e., overabundance of A-type CH3OH at low temperature leading to a
low E/A ratio. Furthermore, we found that CH3OH abundance decreases
beyond Tdust∼30K, which is supported by modeling results. All these
support the fact that CH3OH is easily formed at low-temperature
environments, via successive hydrogenation of CO on cold dust
surfaces.
Description:
The observations of the 175 high-mass star-forming regions were
performed in 2016 June, 2020 August and September, and 2021 April with
the IRAM 30m telescope. The Eight Mixer Receiver (EMIR) with dual
polarization and the Fourier transform spectrometer backend were used
to cover the frequency ranges of 90.6-98.2GHz in the 3mm band,
108.0-115.4GHz and 138.4-146.0GHz in the 2mm band, and 215.6-224.2GHz
in the 1.3mm band.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 89 175 Information on detected CH3OH transition lines
table4.dat 67 1117 Measured CH3OH spectra line parameters toward
our sample by the IRAM 30m
table8.dat 95 111 Measured parameters of A-type and E-type CH3OH
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See also:
VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)
J/A+AS/80/149 : IRAS Sources behind the Solar circle (Wouterloot+ 1989)
J/A+A/308/573 : Ammonia on YSOs IRAS sources (Molinari+ 1996)
J/A+AS/133/29 : Molecular line survey towards UC HII (Hatchell+ 1998)
J/ApJS/125/161 : A database of dense cores mapped in ammonia (Jijina+, 1999)
J/ApJS/155/149 : CH3OH 70-61 A+ maser sources (Kurtz+, 2004)
J/ApJ/702/1615 : CH3OH maser survey of EGOs (Cyganowski+, 2009)
J/ApJS/196/9 : 95GHz maser survey toward GLIMPSE EGOs (Chen+, 2011)
J/A+A/529/A161 : IRDC core G11.11-0.12P1 methanol maps (Gomez+, 2011)
J/MNRAS/418/1689 : Red MSX water maser and ammonia emissions (Urquhart+, 2011)
J/ApJS/202/1 : 1mm spectral line survey toward GLIMPSE EGOs (He+, 2012)
J/other/ChA+A/36.238 : Outflows toward massive cores (Sun+, 2012)
J/ApJS/206/9 : New EGOs from Spitzer GLIMPSE II survey. I. (Chen+, 2013)
J/A+A/560/A73 : Horsehead H2CO and CH3OH 30m and PdBI maps (Guzman+, 2013)
J/A+A/563/A97 : IRAM 30m reduced spectra of 59 sources (Gerner+, 2014)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/MNRAS/452/637 : Distance-limited sample of MYSOs (Maud+, 2015)
J/MNRAS/452/4029 : RMS survey (Urquhart+, 2015)
J/MNRAS/471/100 : Hi-GAL compact source catalog. -71.0<l<67.0 (Elia+, 2017)
J/A+A/599/A139 : ATLASGAL massive clumps dust (Koenig+, 2017)
J/A+A/598/A59 : G31.41+0.31 SMA spectra (Rivilla+, 2017)
J/ApJ/845/116 : Mapping sp. line survey toward W51 in 3mm (Watanabe+, 2017)
J/ApJS/231/20 : A new 95GHz methanol maser catalog. I. (Yang+, 2017)
J/ApJ/846/160 : 6.7GHz Class II methanol maser survey (Yang+, 2017)
J/A+A/611/A6 : ATLASGAL massive clumps H2CO data (Tang+, 2018)
J/MNRAS/473/1059 : Complete sample of Gal. clump properties (Urquhart+, 2018)
J/ApJ/885/131 : ∼200 high-mass SFR plx & PMs with VLBI (Reid+, 2019)
J/ApJ/877/154 : H2CO TMRT obs. of Galactic molecular clouds (Yan+, 2019)
J/ApJS/241/18 : A 6.7GHz methanol maser survey. II. |b|<2° (Yang+, 2019)
J/ApJS/248/18 : 44 and 95GHz obs. of class I methanol masers (Yang+, 2020)
J/ApJS/263/9 : Maser transitions from G358.93-0.03 burst (Miao+, 2022)
J/ApJS/258/19 : 12.2GHz methanol survey toward 6.7GHz masers (Song+, 2022)
J/MNRAS/510/3389 : High-mass star formation evol. trends (Urquhart+, 2022)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Source name
15- 16 I2 h RAh Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27 A1 --- DE- Sign of the Declination (J2000)
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 38 F5.2 arcsec DEs Arcsecond of Declination (J2000)
40- 58 A19 --- CName ATLASGAL catalog source name (1)
60- 64 F5.2 kpc DGC [0/22.7] Galactocentric distance
66- 67 I2 --- Nl [0/19] Number of methanol lines
69- 89 A21 --- Det Maser detection (2)
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Note (1): Name of associated source in Urquhart+ (2018, J/MNRAS/473/1059).
Note (2): Sources with blank values stand for those no maser detected.
The transition in the column indicated that maser was
detected on this transition.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Source name
15- 23 F9.2 MHz Freq [94541.79/220078.56]? Transition line
frequency (1)
25- 28 F4.2 K RMS [0.01/0.5]? Root mean square in Tmb (1)
30- 34 F5.2 K.km/s Int [0.04/84.2]? Integrated line intensity (1)
36- 39 F4.2 K.km/s e_Int [0.0/4.2]? Uncertainty in Int (1)
41- 46 F6.2 km/s VLSR [-93/127.1]? Local standard of rest velocity (1)
48- 51 F4.2 km/s e_VLSR [0/1.2]? Uncertainty in VLSR (1)
53- 57 F5.2 km/s DelV [0.7/22.6]? Line Full-Width at Half-Maximum (1)
59- 62 F4.2 km/s e_DelV [0/6.5]? Uncertainty in DelV (1)
64- 67 F4.2 K Tmb [0.03/8]? Main beam temperature (1)
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Note (1): Sources with blank values stand for those non-detections or those
could not be given one reliable fit due to blending features in the
spectra or narrow maser features in the spectra.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Source name
15- 20 F6.2 K TRot-E [4.5/255]? CH3OH E-type rotational
temperature
22- 26 F5.2 K e_TRot-E [0.07/74]? Uncertainty in TRot-E
28- 33 F6.2 10+14/cm2 N-E [0.3/239]? CH3OH E-type column density
35- 39 F5.2 10+14/cm2 e_N-E [0.05/20]? Uncertainty in N-E
41- 45 F5.2 10-9 X-E [2/91]? CH3OH E-type relative abundance
47- 52 F6.2 10-9 e_X-E [0.1/134]? Uncertainty in X-E
54- 58 F5.2 K TRot-A [0.03/58]? CH3OH A-type rotational
temperature
60- 65 F6.2 K e_TRot-A [0.04/120]? Uncertainty in TRot-A
67- 72 F6.2 10+14/cm2 N-A [0.1/103]? CH3OH A-type column density
74- 78 F5.2 10+14/cm2 e_N-A [0.08/14]? Uncertainty in N-A
80- 84 F5.2 10-9 X-A [0.18/95]? CH3OH A-type relative abundance
86- 90 F5.2 10-9 e_X-A [0.09/12]? Uncertainty in X-A
92- 95 F4.2 --- E/A [0.2/6.1]? Density ratio between E and A
types
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Aug-2023