J/ApJS/258/19 12.2GHz methanol maser survey toward 6.7GHz masers (Song+, 2022)
A 12.2GHz methanol maser survey toward the 6.7GHz counterparts associated
with/without UC HII regions.
Song S.-M., Chen Xi, Shen Z.-Q., Li B., Yang K., Ouyang X., Sobolev A.M.,
Zhao Z., Li X.-Q., Cai F.
<Astrophys. J. Suppl. Ser., 258, 19 (2022)>
=2022ApJS..258...19S 2022ApJS..258...19S
ADC_Keywords: Masers; Radio lines
Keywords: Astrophysical masers ; Star formation ; Interstellar medium
Abstract:
We report a new survey of the 12.2GHz Class II methanol masers toward
a sample of 367 sources with the 6.7GHz methanol masers conducted with
the Shanghai 65m Tianma Radio Telescope. This sample has been
previously made with observations of the radio continuum emission of
UC HII regions by the VLA. A total of 176 sources were detected with
the 12.2GHz methanol maser, with a detection rate of 48%, including
8 new detections. A lower detection rate (<10%) was determined toward
the sources in the Galactic longitude ranges of 60°-180°,
revealing that the physical environments from those sources in the
Local arm or the tails of Galactic arms do not easily excite the
12.2GHz masers. In addition, two detections of highly excited-state OH
masers at the 13.4GHz transition were made, one of which is a new
detection. Compared to previous surveys, one-third of the detected
12.2GHz masers show considerable flux variations, implying the
possible changes of their physical environments associated with
variable radiation fields from their host high-mass young stellar
objects. A positive log-log correlation is found between the
luminosities of the 6.7 and 12.2GHz masers in our observed sample,
suggesting that both the transition masers have similar excitation
conditions. The statistical analysis for the relationships between the
methanol maser luminosity and UC HII region spatial size indicates
that the maser luminosities of both the 6.7 and 12.2GHz transitions
have a decreasing trend with the spatial sizes of the associated UC
HII regions, indicating that the Class II methanol masers might fade
away with the HII region evolution.
Description:
We use Hu+ (2016, J/ApJ/833/18) catalog of the 6.7GHz methanol masers
with high positional accuracies measured by the VLA as our survey
sample for searching the 12.2GHz methanol masers.
The observations were performed during 2017 January and 2018 September
with the 65m Tianma radio telescope (TMRT) in Shanghai, China. We used
the Ku band receiver covering the frequency range of 12-18GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 367 Sample sources with information of the 6.7GHz
methanol maser line parameters
table2.dat 60 9 Line parameters of the 8 newly-detected 12.2GHz
methanol masers
table3.dat 60 252 Line parameters of the 12.2GHz methanol masers
already detected in previous observations
table4.dat 219 147 Comparison between the 12.2GHz maser profiles
of our survey and previous surveys
table5.dat 80 53 Sources with considerable variations of the 12.2GHz
methanol masers compared to previous surveys
table6.dat 38 2 Line parameters of the 13.4GHz OH masers detected
in our survey
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See also:
VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)
J/MNRAS/291/261 : Methanol maser of IRAS-selected sources (Walsh+ 1997)
J/MNRAS/301/640 : Ultracompact H II regions studies. II. (Walsh+, 1998)
J/A+A/413/233 : 12.2GHz methanol survey (Blaszkiewicz+, 2004)
J/ApJ/656/255 : Arecibo methanol maser Gal. plane survey (Pandian+, 2007)
J/other/PASA/26.454 : Precise positions of methanol masers (Caswell, 2009)
J/ApJ/717/L133 : Formaldehyde maser flares in IRAS1856+0408 (Araya+, 2010)
J/AN/333/634 : Torun methanol source catalogue (Szymczak+, 2012)
J/MNRAS/431/1752 : ATLASGAL 6.7GHz methanol masers (Urquhart+, 2013)
J/ApJ/783/130 : Plx of high mass star forming regions (Reid+, 2014)
J/MNRAS/439/2584 : Southern methanol masers at 36 & 44GHz (Voronkov+, 2014)
J/MNRAS/461/2288 : Infall motions in massive star-forming reg. (He+, 2016)
J/ApJ/833/18 : Ultra-compact HII regions & methanol masers (Hu+, 2016)
J/ApJS/227/18 : Stellar bowshock nebulae from MIR (Kobulnicky+, 2016)
J/ApJ/846/160 : 6.7GHz Class II methanol maser survey (Yang+, 2017)
J/ApJ/885/131 : ∼200 high-mass SFR plx & PMs with VLBI (Reid+, 2019)
J/ApJ/877/154 : H2CO TMRT obs. of Gal. molecular clouds (Yan+, 2019)
J/ApJS/241/18 : A 6.7GHz methanol maser survey. II. (Yang+, 2019)
J/ApJ/899/145 : Sulfur isotopes in SFR with ARO & 30m IRAM (Yu+, 2020)
J/ApJS/249/6 : Galactic interstellar ratio 18O/17O. (Zhang+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name, GLLL.lll+BB.bbb
17- 18 I2 h RAh Hour of Right Ascension (J2000) (1)
20- 21 I2 min RAm Minute of Right Ascension (J2000) (1)
23- 27 F5.2 s RAs Second of Right Ascension (J2000) (1)
29- 29 A1 --- DE- Sign of the Declination (J2000) (1)
30- 31 I2 deg DEd Degree of Declination (J2000) (1)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000) (1)
36- 39 F4.1 arcsec DEs Arcsecond of Declination (J2000) (1)
41- 46 F6.2 km/s Vpk [-70/153] Velocity at the spectral peak (2)
48- 52 F5.2 km/s Vr [0.17/21] Velocity range (2)
54- 60 F7.2 Jy Spk6.7 [0.23/3629] Peak flux density (2)
62- 68 F7.2 Jy Spk6.7b [0.6/5196]? Peak flux density (3)
70- 74 F5.2 kpc Dist [0.77/15.77] Distance (4)
76- 76 A1 --- m12 [YN] Detected 12.2GHz methanol maser in survey
78- 78 A1 --- UCHII [YN] UC HII detected by Hu+ (2016, J/ApJ/833/18)
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Note (1): Observed coordinates in our TMRT survey.
Declination signs in the coordinates of G213.704-12.596 and
G232.620+0.995 are corrected for 06 07 47.86-06 22 56.7 (instead of
06 07 47.86+06 22 56.7) and 07 32 09.78-16 58 12.6 (instead of
07 32 09.78+16 58 12.6) at CDS.
Note (2): Line parameters of the 6.7GHz methanol maser observed by
Hu+ (2016, J/ApJ/833/18)
Note (3): Peak flux density of the 6.7GHz maser detected by
Yang+ (2019, J/ApJS/241/18)
Note (4): Distances of the sample sources from the Sun calculated by the methods
of Reid+ (2016ApJ...823...77R 2016ApJ...823...77R and 2019, J/ApJ/885/131).
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Byte-by-byte Description of file: table[23].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name, GLLL.lll+BB.bbb
17- 26 A10 "Y/M/D" Epoch Observation date
28- 34 F7.2 Jy Spk [0.4/1377] Peak flux density
36- 40 F5.1 km/s Vpk [-59/157] Velocity at the peak
42- 46 F5.1 km/s Vr-min [-63/156] Velocity range, lower
48- 52 F5.1 km/s Vr-max [-56/159] Velocity range, upper
54- 60 F7.2 Jy.km/s I [0.16/2036] Integrated flux density
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name, GLLL.lll+BB.bbb
17- 42 A26 --- Survey 12.2GHz survey reference(s) (G1)
44-219 A176 --- Comp Comparisons of 12.2GHz masers
between different surveys
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Source name, GLLL.lll+BB.bbb
17- 22 F6.2 Jy Spk12.2 [0.84/748.25] Peak flux density of the 12.2GHz,
this survey
24- 28 F5.1 Jy Spk12.2b [0.4/401] Peak flux density of the 12.2GHz,
literature (1)
30- 35 F6.1 Jy Spk6.7 [2.7/5196] Peak flux density of the 6.7GHz
methanol maser detected by
Yang+ (2019, J/ApJS/241/18)
37- 41 A5 --- r_Date1 Reference for first observation date (G1)
42 A1 --- --- [(]
43- 49 A7 "Y/M" Date1 First observation date
50 A1 --- --- [)]
52- 56 A5 --- r_Date2 Reference for second observation date (G1)
57 A1 --- --- [(]
58- 64 A7 "Y/M" Date2 Second observation date if any
65 A1 --- --- [)]
67- 71 A5 --- r_Date3 Reference for third observation date (G1)
72 A1 --- --- [(]
73- 79 A7 "Y/M" Date3 Third observation date if any
80 A1 --- --- [)]
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Note (1): Breen et al. (2012MNRAS.421.1703B 2012MNRAS.421.1703B, 2012MNRAS.426.2189B 2012MNRAS.426.2189B,
2014MNRAS.438.3368B 2014MNRAS.438.3368B and 2016MNRAS.459.4066B 2016MNRAS.459.4066B)
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name, GLLL.lll+BB.bbb
15- 18 F4.2 Jy Spk [1/2.16] Peak flux density
20- 23 F4.1 km/s Vpk [-2.6/14.2] Velocity at the peak
25- 28 F4.1 km/s Vr-min [-3.8/13.8] Velocity range, lower
30- 33 F4.1 km/s Vr-max [-1.8/14.5] Velocity range, upper
35- 38 F4.2 Jy.km/s I [0.22/0.51] Integrated flux density
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Global notes:
Note (G1): Survey references as follows:
Bla04 = Blaszkiewicz & Kus (2004, J/A+A/413/233);
Bre10 = Breen et al. (2010MNRAS.406.1487B 2010MNRAS.406.1487B and 2010MNRAS.401.2219B 2010MNRAS.401.2219B);
Bre12 = Breen et al. (2012MNRAS.421.1703B 2012MNRAS.421.1703B and 2012MNRAS.426.2189B 2012MNRAS.426.2189B);
Bre14 = Breen et al. (2014MNRAS.438.3368B 2014MNRAS.438.3368B);
Bre16 = Breen et al. (2016MNRAS.459.4066B 2016MNRAS.459.4066B);
Bre18 = Breen et al. (2018MNRAS.474.3898B 2018MNRAS.474.3898B);
Cas93 = Caswell et al. (1993MNRAS.260..425C 1993MNRAS.260..425C);
Cas95 = Caswell et al. (1995MNRAS.274.1126C 1995MNRAS.274.1126C);
Gay94 = Gaylard et al. (1994MNRAS.269..257G 1994MNRAS.269..257G).
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History:
From electronic version of the journal
13-Jun-2022:Insert into VizieR
* 13-May-2024: declination signs for two objects corrected in Table 1.
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Apr-2022