J/ApJ/763/2 95GHz methanol masers in molecular outflows (Gan+, 2013)
A search for 95 GHz class I methanol masers in molecular outflows.
Gan C.-G., Chen X., Shen Z.-Q., Xu Y., Ju B.-G.
<Astrophys. J., 763, 2 (2013)>
=2013ApJ...763....2G 2013ApJ...763....2G
ADC_Keywords: Masers ; Radio lines ; Interstellar medium
Keywords: galaxies: star formation; ISM: jets and outflows; masers;
radio lines: ISM
Abstract:
We have observed a sample of 288 molecular outflow sources including
123 high-mass and 165 low-mass sources in order to search for class I
methanol masers at the 95GHz transition and to investigate the
relationship between outflow characteristics and class I methanol
maser emission with the Purple Mountain Observatory 13.7m radio
telescope. Our survey detected 62 sources with 95GHz methanol masers
above a 3σ detection limit, which includes 47 high-mass sources
and 15 low-mass sources. Therefore, the detection rate is 38% for
high-mass outflow sources and 9% for low-mass outflow sources,
suggesting that class I methanol masers are relatively easily excited
in high-mass sources. There are 37 newly detected 95GHz methanol
masers (including 27 high-mass and 10 low-mass sources), 19 of which
are newly identified (i.e., first identification) class I methanol
masers (including 13 high-mass and 6 low-mass sources). A statistical
analysis of the distributions of maser detections with the outflow
parameters reveals that the maser detection efficiency increases with
the outflow properties (e.g., mass, momentum, kinetic energy,
mechanical luminosity of outflows, etc.). Systematic investigations of
the relationships between the intrinsic luminosity of methanol masers
and the outflow properties (including mass, momentum, kinetic energy,
bolometric luminosity, and mass-loss rate of the central stellar
sources) indicate a positive correlation. This further supports the
theory that class I methanol masers are collisionally pumped and
associated with shocks when outflows interact with the surrounding
ambient medium.
Description:
Single-point observations of 95GHz class I methanol masers toward the
selected 288 sources were made over a period from 2010 June to
September with the PMO 13.7m telescope in Delingha, China. The spectra
were recorded with an Acousto-Optical Spectrometer backend, which has
a total bandwidth of 42.7MHz, resulting in a velocity resolution of
0.13km/s and total velocity coverage of 135km/s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 115 136 Detected 95GHz methanol masers in high-mass sources
(47 high-mass sources)
table3.dat 115 38 Detected 95GHz methanol masers in low-mass sources
(15 low-mass sources)
table6.dat 57 226 Sources that have no 95GHz methanol masers detected
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See also:
VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)
J/AZh/89/611 : Class I methanol maser catalog (Bayandina+, 2012)
J/ApJS/200/5 : 95GHz class I methanol maser survey (Chen+, 2012)
J/ApJS/196/9 : 95GHz methanol maser survey toward GLIMPSE EGOs (Chen+, 2011)
J/ApJ/702/1615 : CH3OH maser survey of EGOs (Cyganowski+, 2009)
J/other/PASA/26.454 : Precise positions of methanol masers (Caswell, 2009)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/AZh/84/839 : Methanol emission of isolated maser (Larionov+, 2007)
J/AZh/84/579 : Catalog of Class I methanol masers (Val'tts+, 2007)
J/ApJ/656/255 : Arecibo methanol maser Survey (Pandian+, 2007)
J/MNRAS/359/1498 : Class I and class II methanol masers (Ellingsen+, 2005)
J/A+A/432/737 : General Cat. of 6.7GHz Methanol Masers (Pestalozzi+, 2005)
J/A+A/426/503 : Cat. of high velocity molecular outflows (Update) (Wu+ 2004)
J/ApJS/155/149 : CH3OH 70-61 A+ maser sources (Kurtz+, 2004)
J/A+A/403/1095 : 6.7GHz methanol masers survey of YSO (Minier+, 2003)
J/A+A/314/615 : Maps of the 36 GHz methanol emission (Liechti+, 1996)
J/AZh/72/22 : A 95 GHz Survey of Methanol Masers (Valtts+, 1995)
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1 A1 --- n_Name [abc] New or known detection (1)
3- 15 A13 --- Name Source name (sorted by galactic coordinates)
17- 31 A15 --- OName Other name (2)
33- 34 I2 h RAh Hour of right ascension (J2000)
36- 37 I2 min RAm Minute of right ascension (J2000)
39- 42 F4.1 s RAs Second of right ascension (J2000)
44 A1 --- DE- Sign of declination (J2000)
45- 46 I2 deg DEd Degree of declination (J2000)
48- 49 I2 arcmin DEm Arcminute of declination (J2000)
51- 52 I2 arcsec DEs Arcsecond of declination (J2000)
54- 59 F6.2 km/s Vlsr [-57.6/85.7] Velocity at peak VLSR
61- 64 F4.2 km/s e_Vlsr [0/0.7] Vlsr uncertainty
66- 70 F5.2 km/s DV [0.2/12.4] Line FWHM ΔV
72- 75 F4.2 km/s e_DV [0.03/6.1] DelV uncertainty
77- 81 F5.2 Jy P [0.6/73] Momentum of outflows (P)
83- 88 F6.2 Jy.km/s S [0.3/409] Integrated intensity at 95GHz
90- 94 F5.2 Jy.km/s e_S [0.03/11] S uncertainty
96-102 F7.2 Jy.km/s Sint [1/1071]? Total 95GHz integrated intensity
104-107 F4.2 Jy rms [0.1/3]? 1σrms noise of the
observations
109 A1 --- A36 [Y-] 36GHz classI CH3OH maser association? (3)
111 A1 --- A44 [Y-] 44GHz classI CH3OH maser association? (4)
113 A1 --- A95 [Y-] 95GHz classI CH3OH maser association? (5)
115 A1 --- A6.7 [Y-] 6.7GHz classII CH3OH maser
association? (6)
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Note (1): Flag as follows:
a = Sources that had 95GHz class I methanol masers detected previously.
b = Sources that have 95GHz class I methanol masers detected for the first
time.
c = Sources that only have 95GHz class I methanol masers detected thus far
(newly identified class I methanol masers).
Note (2): Other source names from Wu et al. (2004, Cat. J/A+A/426/503) and so
the corresponding equatorial coordinates.
Note (3): Liechti & Wilson (1996, Cat. J/A+A/314/615).
Note (4): Val'tts & Larionov (2007, Cat. J/AZh/84/579),
Kurtz et al. (2004, Cat. J/ApJS/155/149),
Larionov & Val'tts (2007, Cat. J/AZh/84/839),
Fontani et al. (2010A&A...517A..56F 2010A&A...517A..56F),
Kalenskii et al. (2006ARep...50..289K 2006ARep...50..289K, 2010MNRAS.405..613K 2010MNRAS.405..613K),
Litovchenko et al. (2011ARep...55.1086L 2011ARep...55.1086L), and
Bae et al. (2011ApJS..196...21B 2011ApJS..196...21B).
Note (5): Val'tts et al. (1995, Cat. J/AZh/72/22),
Val'tts & Larionov (2007, Cat. J/AZh/84/579),
Kalenskii et al. (1994A&AS..103..129K 1994A&AS..103..129K, 2006ARep...50..289K 2006ARep...50..289K),
Larionov et al. (1999A&AS..139..257L 1999A&AS..139..257L),
Fontani et al. (2010A&A...517A..56F 2010A&A...517A..56F), and
Chen et al. (2011, Cat. J/ApJS/196/9; 2012, Cat. J/ApJS/200/5).
Note (6): Xu et al. (2009A&A...507.1117X 2009A&A...507.1117X),
Caswell (2009, Cat. J/other/PASA/26.454),
Caswell et al. (2010, Cat. VIII/96; 2011MNRAS.417.1964C 2011MNRAS.417.1964C), and
Green et al. (2010-2012, Cat. VIII/96)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name
15- 29 A15 --- OName Other name from Wu et al., 2004,
Cat. J/A+A/426/503
31- 32 I2 h RAh Hour of right ascension (J2000)
34- 35 I2 min RAm Minute of right ascension (J2000)
37- 40 F4.1 s RAs Second of right ascension (J2000)
42 A1 --- DE- Sign of declination (J2000)
43- 44 I2 deg DEd Degree of declination (J2000)
46- 47 I2 arcmin DEm Arcminute of declination (J2000)
49- 50 I2 arcsec DEs Arcsecond of declination (J2000)
52- 55 F4.2 Jy rms [0.3/2.8] rms noise
57 A1 --- Mass Mass type (L: low-mass source or H: high-mass)
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 22-Oct-2014