J/ApJS/245/12 6.7GHz methanol masers & RRLs in MSX regions (Ouyang+, 2019)
The relationship between 6.7GHz methanol masers and radio recombination lines
in high-mass star-forming regions.
Ouyang X.-J., Chen Xi, Shen Z.-Q., Yang K., Li X.-Q., Chen H.-Y., Zhao Z.,
Sobolev A.M.
<Astrophys. J. Suppl. Ser., 245, 12 (2019)>
=2019ApJS..245...12O 2019ApJS..245...12O
ADC_Keywords: H II regions; Masers; Radio lines; Interstellar medium
Keywords: Astrophysical masers ; Interstellar medium ; H II regions ; Surveys ;
Star formation ; Interstellar molecules
Abstract:
We report a systematic survey of a 6.7GHz Class II methanol maser
toward a sample of 448 sources selected from the Red Midcourse Space
Experiment Source catalog. These sample sources are composed of
high-mass star-forming region (HMSFR) candidates and have been studied
as tracers of HMSFRs, such as water masers or radio continuum emission
of ultracompact HII region. The survey was conducted using the
Shanghai Tianma Radio Telescope. Through the observations, we
simultaneously studied the 4.7 and 6.0GHz excited-state interstellar
hydroxyl (OH) maser lines and 10 hydrogen radio recombination lines
(RRLs) in the C band. In total, we detected 6.7GHz methanol masers and
RRLs from 102 and 116 sources, respectively. In addition, 4, 3, and 10
sources exhibit OH masers at 4765.56, 6030.75, and 6035.09MHz
transitions, respectively. Through the survey, we identified four new
6.7GHz methanol maser sources and three new excited-state OH maser
sources (one at 4750MHz and two at 6035MHz). The statistical analysis
demonstrated that there is a positive correlation of luminosity
between 6.7GHz methanol masers and RRLs. A good correlation of
integrated luminosity between radio continuum emission and the 6.7GHz
methanol masers is presented with respect to the RRL emission sources.
The average of the integrated luminosities of the RRLs in the sources
with 6.7GHz masers is greater than those without the 6.7GHz masers;
similarly, the average of integrated luminosities of the 6.7GHz
methanol masers in the sources with RRLs is greater than those without
the RRLs. Moreover, we found that the averages of the emission measure
and electron temperature of HII regions associated with 6.7GHz
methanol masers are larger than those without the 6.7GHz methanol
masers. This suggests that the masers are most likely produced in high
gas density and luminous regions with brighter RRLs and higher radio
continuum emission.
Description:
The observations were conducted using the Shanghai Tianma Radio
Telescope (TMRT) from 2017 March to 2017 August. The 6.7GHz methanol
maser, 10 hydrogen radio recombination lines (H98α-H102α,
H108α-H113α), and four excited-state OH maser lines were
simultaneously covered in the survey.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 53 207 Ultracompact HII region sample with radio
continuum emission
table2.dat 57 398 Water maser or ammonia emission sample
table4.dat 228 98 Comparisons of the 6.7GHz methanol masers between
our survey and previous surveys
table5.dat 169 488 Properties of masers, radio recombination lines
(RRLs) and radio continuum emission
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See also:
V/114 : MSX6C Infrared Point Source Catalog (Egan+, 2003)
VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)
J/A+A/171/261 : RRLs of Southern HII Regions (Caswell+ 1987)
J/MNRAS/291/261 : Methanol maser of IRAS-selected sources (Walsh+ 1997)
J/A+AS/137/43 : OH/H2O masers database (Forster+, 1999)
J/A+AS/143/269 : 6.7GHz methanol maser emission survey (Szymczak+, 2000)
J/A+A/403/1095 : 6.7GHz methanol maser survey of low-mass YSO (Minier+, 2003)
J/A+A/417/615 : Maser and outflows in UC HII region (Codella+, 2004)
J/ApJS/155/149 : CH3OH 70-61 A+ maser sources (Kurtz+, 2004)
J/MNRAS/359/1498 : Class I and class II methanol masers (Ellingsen+, 2005)
J/AJ/129/348 : Radio compact HII regions in the Milky Way (Giveon+, 2005)
J/A+A/432/737 : General Cat. of 6.7GHz Methanol Masers (Pestalozzi+, 2005)
J/A+A/434/613 : Water maser survey of methanol masers (Szymczak+, 2005)
J/MNRAS/377/571 : GLIMPSE 6.7GHz methanol masers non-det. (Ellingsen+, 2007)
J/A+A/487/253 : The RMS survey: 13CO observations of YSOs (Urquhart+, 2008)
J/ApJ/702/1615 : CH3OH maser survey of EGOs (Cyganowski+, 2009)
J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)
J/ApJS/194/32 : HII Region Discovery Survey (HRDS). II. (Anderson+, 2011)
J/ApJS/196/9 : 95GHz methanol maser survey of GLIMPSE EGOs (Chen+, 2011)
J/MNRAS/418/1689 : Red MSX water maser and ammonia emissions (Urquhart+, 2011)
J/MNRAS/416/1764 : H2O Southern Galactic Plane Survey (HOPS) (Walsh+, 2011)
J/ApJS/200/5 : 95GHz class I methanol maser survey (Chen+, 2012)
J/AN/333/634 : Torun methanol source catalogue (Szymczak+, 2012)
J/ApJS/206/9 : New EGOs from Spitzer GLIMPSE II survey. I. (Chen+, 2013)
J/ApJ/763/2 : 95GHz methanol masers in molecular outflows (Gan+, 2013)
J/ApJS/208/11 : Red MSX Source Survey: massive protostars (Lumsden+, 2013)
J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014)
J/MNRAS/439/2584 : Southern methanol masers at 36 and 44GHz (Voronkov+, 2014)
J/MNRAS/442/2240 : Accurate water maser positions from HOPS (Walsh+, 2014)
J/ApJ/833/18 : Ultra-compact HII regions & methanol masers. I. (Hu+, 2016)
J/ApJS/227/26 : ATCA obs. of ground-state OH masers (Qiao+, 2016)
J/ApJ/846/160 : 6.7GHz Class II methanol maser survey (Yang+, 2017)
J/ApJS/231/20 : A new 95GHz methanol maser catalog. I. (Yang+, 2017)
J/ApJS/234/33 : A GBT survey of large Galactic HII regions (Anderson+, 2018)
J/ApJS/241/18 : A 6.7GHz methanol maser survey. II. |b|<2° (Yang+, 2019)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- MSX6C Source name (GLLL.llll+BB.bbbb)
19- 20 I2 h RAh Hour of Right Ascension (J2000)
22- 23 I2 min RAm Minute of Right Ascension (J2000)
25- 29 F5.2 s RAs Second of Right Ascension (J2000)
31- 31 A1 --- DE- Sign of the Declination (J2000)
32- 33 I2 deg DEd Degree of Declination (J2000)
35- 36 I2 arcmin DEm Arcminute of Declination (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of Declination (J2000)
43- 43 A1 --- D-6668MHz [y ] Detection, 6668MHz tracer
45- 45 A1 --- D-RRLs [y ] Detection, RRLs tracer
47- 47 A1 --- D-4765MHz [y ] Detection, 4765MHz tracer
49- 49 A1 --- D-6030MHz [y ] Detection, 6030MHz tracer
51- 51 A1 --- D-6035MHz [y ] Detection, 6035MHz tracer
53- 53 A1 --- T2 [y ] Is the source also listed in Table 2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- MSX6C Source name (GLLL.llll+BB.bbbb)
19- 20 I2 h RAh Hour of Right Ascension (J2000)
22- 23 I2 min RAm Minute of Right Ascension (J2000)
25- 29 F5.2 s RAs Second of Right Ascension (J2000)
31- 31 A1 --- DE- Sign of the Declination (J2000)
32- 33 I2 deg DEd Degree of Declination (J2000)
35- 36 I2 arcmin DEm Arcminute of Declination (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of Declination (J2000)
43- 43 A1 --- D-Water [yn ] Detection, Water
45- 45 A1 --- D-Ammonia [yn ] Detection, Ammonia
47- 47 A1 --- D-6668MHz [y ] Detection, 6668MHz tracer
49- 49 A1 --- D-RRLs [y ] Detection, RRLs tracer
51- 51 A1 --- D-4765MHz [y ] Detection, 4765MHz tracer
53- 53 A1 --- D-6030MHz [y ] Detection, 6030MHz tracer
55- 55 A1 --- D-6035MHz [y ] Detection, 6035MHz tracer
57- 57 A1 --- T1 [y ] Is the source also listed in Table 1
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- MSX6C Source name (GLLL.llll+BB.bbbb)
18 A1 --- --- [;]
19- 35 A17 --- Assoc Associated MSX6C to
first MSX6C (GLLL.llll+BB.bbbb)
38-109 A72 --- OName Name(s) in other surveys (1)
111-115 A5 --- r_OName References for sources in other surveys (2)
117-135 A19 arcmin Offsets Position offset(s) from MMB position (3)
137-228 A92 --- Notes Notes on differences between this survey and
others
--------------------------------------------------------------------------------
Note (1): The name of the source adopted in other surveys. This is a semicolon
delimited list for objects detected in multiple surveys.
Note (2): References as follows:
MMB = the Methanol Multibeam survey -- Caswell+ (2010MNRAS.404.1029C 2010MNRAS.404.1029C),
(2011MNRAS.417.1964C 2011MNRAS.417.1964C); Green et al. (2009MNRAS.392..783G 2009MNRAS.392..783G),
(2010MNRAS.409..913G 2010MNRAS.409..913G), (2012MNRAS.420.3108G 2012MNRAS.420.3108G);
Breen et al. (2015MNRAS.450.4109B 2015MNRAS.450.4109B);
P = Pestalozzi et al. (2005A&A...432..737P 2005A&A...432..737P);
O = Olmi et al. (2014A&A...566A..18O 2014A&A...566A..18O);
M = Menten (1991ApJ...380L..75M 1991ApJ...380L..75M);
S00 = Szymczak et al. (2000A&AS..143..269S 2000A&AS..143..269S);
S12 = Szymczak et al. (2012AN....333..634S 2012AN....333..634S);
X08 = Xu et al. (2008A&A...485..729X 2008A&A...485..729X).
Note (3): This is a semi-colon delimited list of offsets; one for each other
survey detection.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- MSX6C Source name (GLLL.llll+BB.bbbb)
18 A1 --- --- [;]
19- 35 A17 --- Assoc Associated MSX6C to
first MSX6C (GLLL.llll+BB.bbbb)
38- 38 A1 --- SLflag [s ] Sidelobe effect flag (1)
40- 49 A10 --- Tracer Tracer (2)
51- 52 A2 --- x_Si Units for Si, depending on Tracer
54- 60 A7 --- x_Sp Units for Sp, depending on Tracer
62- 68 A7 --- x_logLi Units for logLi, depending on Tracer
70- 81 A12 --- x_logLp Units for logLp, depending on Tracer
83- 91 F9.3 --- Si [0/70795]? Integrated flux density in Tracer
95-103 F9.3 --- Sp [0.001/15489]? Peak flux density in Tracer
105-109 F5.1 km/s Vpeak [-64.1/116]? Velocities at peak emission
111-115 F5.1 km/s VR1 [-64/111]? Velocity Range, parameter 1 (3)
117-123 F7.3 km/s VR2 [-60/120.3]? Velocity Range, parameter 2 (3)
125-128 F4.1 --- logLi [-2.7/6.3]? Integrated intensity, log
130-134 F5.1 --- logLp [-2.8/962.4]? Peak intensity, log
136-138 F3.1 [K] logTe [4.5/7.5]? Electron temperature, log
140-143 F4.1 [pc/cm6] logEM [6.2/10]? Emission measure, log
145-149 F5.2 kpc Dist [0.6/18]? Distances of sources
151-154 F4.2 kpc e_Dist [0.04/1.5]? Symmetric (or lower)
uncertainty on Dist
156-159 F4.2 kpc E_Dist [0.27]? Upper uncertainty on Dist
161-163 A3 --- Arm Spiral arm(s) (4)
165-169 A5 --- Refs Reference(s) of previously known methanol
masers, continuum emissions and water
masers (5)
--------------------------------------------------------------------------------
Note (1): The emission may be contributed from neighborhoods due to sidelobe
effect of single dish observations.
Note (2): RRL may be repeated multiple times for a single source because
multiple RRL velocity components were detected from the source.
Note (3): Velocity range parameters vary for different tracers --
CH_3OH 6.7: VR1 and VR2 are the min/max velocity range for the masers;
RRLs = VR1 is the FWHM of RRL determined by Gaussian fitting;
VR2 is the FWHM error.
Note (4): Spiral arms as follows:
... = No assignment;
3kF = 3-kpc far side;
AqS = Aquila Spur;
AqR = Aquila Rift;
Loc = Local arm;
LoS = Local spur;
Nor = Norma arm;
Out = Outer arm;
Per = Perseus arm;
ScF = Scutum far;
ScN = Scutum near;
SgF = Sagittarius far;
SgN = Sagittarius near.
Note (5): References as follows:
New = new masers detected in our survey
1 = MMB: the Methanol Multibeam survey -- Caswell+ (2010MNRAS.404.1029C 2010MNRAS.404.1029C),
(2011MNRAS.417.1964C 2011MNRAS.417.1964C); Green et al. (2009MNRAS.392..783G 2009MNRAS.392..783G),
(2010MNRAS.409..913G 2010MNRAS.409..913G), (2012MNRAS.420.3108G 2012MNRAS.420.3108G);
Breen et al. (2015MNRAS.450.4109B 2015MNRAS.450.4109B);
2 = Pestalozzi et al. (2005A&A...432..737P 2005A&A...432..737P);
3 = Urquhart et al. (2009A&A...501..539U 2009A&A...501..539U);
4 = Urquhart et al. (2011MNRAS.418.1689U 2011MNRAS.418.1689U);
5 = Kim et al. (2018ApJS..236...31K 2018ApJS..236...31K);
6 = Sanna et al. (2014ApJ...781..108S 2014ApJ...781..108S);
7 = Xu et al. (2011ApJ...733...25X 2011ApJ...733...25X);
8 = Immer et al. (2013A&A...553A.117I 2013A&A...553A.117I);
9 = Wu et al. (2014A&A...566A..17W 2014A&A...566A..17W);
10 = Xu et al. (2009ApJ...693..413X 2009ApJ...693..413X);
11 = Rygl et al. (2012A&A...539A..79R 2012A&A...539A..79R);
12 = Moscadelli et al. (2009ApJ...693..406M 2009ApJ...693..406M);
13 = Choi et al. (2014ApJ...790...99C 2014ApJ...790...99C);
14 = Xu et al. (2008A&A...485..729X 2008A&A...485..729X);
15 = Olmi et al. (2014A&A...566A..18O 2014A&A...566A..18O);
16 = Menten (1991ApJ...380L..75M 1991ApJ...380L..75M);
17 = Szymczak et al. (2000A&AS..143..269S 2000A&AS..143..269S);
18 = Szymczak et al. (2012AN....333..634S 2012AN....333..634S).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Mar-2020