J/ApJS/200/5 95GHz class I methanol maser survey (Chen+, 2012)
A 95 GHz class I methanol maser survey toward a sample of GLIMPSE point sources
associated with BGPS clumps.
Chen X., Ellingsen S.P., He J.-H., Xu Y., Gan C.-G., Shen Z.-Q., An T.,
Sun Y., Ju B.-G.
<Astrophys. J. Suppl. Ser., 200, 5 (2012)>
=2012ApJS..200....5C 2012ApJS..200....5C
ADC_Keywords: Masers ; Millimetric/submm sources ; Photometry, infrared ;
Radio lines ; Interstellar medium ; Surveys
Keywords: infrared: ISM - ISM: molecules - masers - radio lines: ISM -
stars: formation
Abstract:
We report a survey with the Purple Mountain Observatory 13.7m radio
telescope for class I methanol masers from the 95GHz (80-71A+)
transition. Two hundred and fourteen target sources were selected by
combining information from both the Spitzer GLIMPSE and 1.1mm Bolocam
Galactic Plane Survey (BGPS) catalogs. The observed sources satisfy
the GLIMPSE mid-IR criteria of [3.6]-[4.5]>1.3, [3.6]-[5.8]>2.5,
[3.6]-[8.0]>2.5 and 8.0um mag less than 10; they also have an
associated 1.1mm BGPS source. Class I methanol maser emission was
detected in 63 sources, corresponding to a detection rate of 29% for
this survey. For the majority of detections (43), this is the first
identification of class I methanol masers associated with these
sources. We show that the intensity of the class I methanol maser
emission is not closely related to mid-IR intensity or the colors of
the GLIMPSE point sources; however, it is closely correlated with
properties (mass and beam-averaged column density) of the BGPS
sources. Comparison of measures of star formation activity for the
BGPS sources with and without class I methanol masers indicates that
the sources with class I methanol masers usually have higher column
density and larger flux density than those without them.
Description:
We used the released catalogs from the GLIMPSE survey (version 2.0;
Cat. II/293) and the BGPS (version 1.0.1; Cat. J/ApJS/188/123) to
construct a target sample for our class I methanol maser search. The
observations of the 80-71A+ (95.1964630GHz) class I methanol
maser transition were made using the PMO 13.7m telescope in Delingha,
China during 2011 March-April.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 123 214 Sample parameters
table2.dat 36 214 Observed source positions and observing rms noise
table3.dat 46 133 Observed properties of 95GHz class I methanol
maser sources detected
table5.dat 45 63 Related parameters of the detected class I
methanol masers
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See also:
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
J/ApJS/196/9 : 95GHz methanol maser survey toward GLIMPSE EGOs (Chen+, 2011)
J/ApJS/195/14 : The Bolocam Galactic Plane Survey. V. (Schlingman+, 2011)
J/ApJS/188/123 : The Bolocam Galactic Plane Survey. II. (Rosolowsky+, 2010)
J/ApJ/721/137 : The Bolocam Galactic Plane Survey (BGPS) (Bally+, 2010)
J/MNRAS/377/571 : GLIMPSE 6.7GHz methanol masers non-detections (Ellingsen+,
2007)
J/AZh/84/579 : Catalog of Class I methanol masers (Val'tts+, 2007)
J/ApJ/656/255 : Arecibo methanol maser Galactic Plane Survey (Pandian+, 2007)
J/MNRAS/359/1498 : Class I and class II methanol masers (Ellingsen+, 2005)
J/A+A/428/1019 : Rest frequencies of methanol maser lines (Mueller+, 2004)
J/A+A/410/597 : Warm dust near methanol masers (Walsh+, 2003)
J/other/ChJAA/3.49 : Velocity of methanol maser sources (Xu+, 2003)
J/MNRAS/291/261 : Methanol maser of IRAS-selected sources (Walsh+ 1997)
J/A+AS/110/81 : Methanol masers towards IRAS sources (van der Walt+ 1995)
J/AZh/72/22 : A 95 GHz Survey of Methanol Masers (Valtts+, 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/214] Index number (G1)
5- 21 A17 --- SSTGLMC GLIMPSE point source name (GLLL.llll+BB.bbbb)
23- 27 F5.2 mag [3.6] Spitzer/IRAC 3.6 micron band magnitude
29- 32 F4.2 mag e_[3.6] Uncertainty in [3.6]
34- 38 F5.2 mag [4.5] Spitzer/IRAC 4.5 micron band magnitude
40- 43 F4.2 mag e_[4.5] Uncertainty in [4.5]
45- 49 F5.2 mag [5.8] Spitzer/IRAC 5.8 micron band magnitude
51- 54 F4.2 mag e_[5.8] Uncertainty in [5.8]
56- 59 F4.2 mag [8.0] Spitzer/IRAC 8.0 micron band magnitude
61- 64 F4.2 mag e_[8.0] Uncertainty in [8.0]
66- 69 I4 --- ID [1051/6501] BGPS source identifier (1)
71- 85 A15 --- BGPS BGPS source name (GLLL.lll+BB.bbb) (1)
87- 92 F6.2 arcsec Rad [5.13/128.72]? Radius of BGPS source (1)
94- 98 F5.3 Jy S40 BGPS source 1.1mm flux density with 40"
aperture (2)
100-104 F5.3 Jy e_S40 Uncertainty in S40
106-111 F6.3 Jy Sint BGPS source 1.1mmm integrated flux density (2)
113-117 F5.3 Jy e_Sint Uncertainty in Sint
119-123 F5.2 10+22/cm2 NH2 Beam-averaged H2 column density;
see section 4.2
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Note (1): BGPS = Bolocam Galactic Plane Survey (Rosolowsky et al. 2010,
Cat. J/ApJS/188/123; Schlingman et al. 2001, Cat. J/ApJS/195/14).
Blank radius indicate unresolved sources with the BGPS beam.
Note (2): Note that a flux calibration correction factor of 1.5 should be
applied to both the aperture and the integrated flux densities listed
here to calculate BGPS gas mass and column/volume density (see Sec.
4.2). In addition, an aperture correction of 1.46 is needed to apply
to aperture flux density within 40" after applied a flux calibration
correction factor of 1.5 to calculate the beam-averaged column density.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/214] Index number (G1)
5- 8 I4 --- ID [1051/6501] BGPS source identifier
10- 11 I2 h RAh [17/19] Hour of Right Ascension (J2000)
13- 14 I2 min RAm Minute of Right Ascension (J2000)
16- 20 F5.2 s RAs Second of Right Ascension (J2000)
22 A1 --- DE- [-] Sign of the Declination (J2000)
23- 24 I2 deg DEd [0/26] Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcminute of Declination (J2000)
29- 32 F4.1 arcsec DEs Arcsecond of Declination (J2000)
34- 36 F3.1 Jy rms [0.4/1.2] The rms noise of target source
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [11/212] Index number (G1)
5- 10 F6.2 km/s VLSR Peak Local Standard of Rest velocity (1)
12- 15 F4.2 km/s e_VLSR Uncertainty in VLSR
17- 21 F5.2 km/s DelV Line FWHM (1)
23- 26 F4.2 km/s e_DelV Uncertainty in DelV
28- 31 F4.1 Jy.km/s Si Integrated intensity (1)
33- 35 F3.1 Jy.km/s e_Si Uncertainty in Si
37- 40 F4.1 Jy Sp Peak flux density (1)
42- 46 F5.1 Jy.km/s Sint Total integrated flux density (2)
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Note (1): Of each maser feature estimated from Gaussian fits to the 95GHz
class I methanol maser lines.
Note (2): Of the maser spectrum obtained from summing the integrated flux
density of all maser features in each source in column "Si".
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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- 3 I3 --- Seq [11/212] Index number (G1)
4- 7 A4 --- f_Seq [DGS, ] Flag(s) on Seq (1)
9- 12 F4.1 kpc Dist [1.6/14.7] Kinematic distance (2)
13 A1 --- f_Dist [*] Assumed distance value (2)
15- 19 F5.1 10-6Lsun Lum Integrated luminosity of the 95GHz methanol
maser
21- 24 I4 --- ID [1251/6479] BGPS source number
26- 30 I5 Msun Mass BGPS derived gas mass
32- 36 F5.1 10+3/cm3 nH2 ? BGPS H2 average volume (3)
38- 41 F4.1 10+22/cm2 NH2 ? BGPS H2 column density (3)
43 A1 --- IRDC [Y/N] Association with IR Dark Cloud ?
45 A1 --- Mas [Y/N]? Association with a 6.7GHz methanol
maser? (4)
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Note (1): The sources marked by G, D, or S overlaid with that in reference:
G = Green & McClure-Griffiths (2011MNRAS.417.2500G 2011MNRAS.417.2500G)
D = Dunham et al. (2011ApJ...741..110D 2011ApJ...741..110D)
S = Schlingman et al. (2011, Cat. J/ApJS/195/14)
Note (2): The kinematic distance for the source, estimated from the Galactic
rotation curve of Reid et al. (2009ApJ...700..137R 2009ApJ...700..137R). For sources
overlapped with Green & McClure-Griffiths (2011MNRAS.417.2500G 2011MNRAS.417.2500G), we
adopted the distances estimated from their work. For the sources
(marked by *) whose distances cannot be derived from the Galactic
rotation curve, a distance of 4kpc is adopted for the source with an
IRDC association (N33), and that determined in Schlingman et al.
(2011, Cat. J/ApJS/195/14) for the other two sources (N194 and N210).
Note (3): The gas volume and column densities cannot be determined because of
the absence of radius information for the sources that are unresolved
by the BGPS beam.
Note (4): Association with a 6.7GHz methanol maser for which a precise position
has been measured. The positions of the 6.7GHz class II methanol
masers were identified from published 6.7GHz maser catalogs (Caswell
2009PASA...26..454C 2009PASA...26..454C; Caswell et al. 2010MNRAS.404.1029C 2010MNRAS.404.1029C,
2011MNRAS.417.1964C 2011MNRAS.417.1964C; Green et al. 2010MNRAS.409..913G 2010MNRAS.409..913G,
2012MNRAS.420.3108G 2012MNRAS.420.3108G).
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Global notes:
Note (G1): Which is organized by increasing galactic longitude.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Jul-2012