J/ApJ/833/18 Ultra-compact HII regions & methanol masers. I. (Hu+, 2016)
On the relationship of UC HII regions and class II methanol masers.
I. Source catalogs.
Hu B., Menten K.M., Wu Y., Bartkiewicz A., Rygl K., Reid M.J.,
Urquhart J.S., Zheng X.
<Astrophys. J., 833, 18-18 (2016)>
=2016ApJ...833...18H 2016ApJ...833...18H (SIMBAD/NED BibCode)
ADC_Keywords: Masers ; H II regions ; Radio continuum ; Radial velocities
Keywords: catalogs; ISM: molecules; masers; stars: formation
Abstract:
We conducted Very Large Array C-configuration observations to measure
positions and luminosities of Galactic Class II 6.7GHz methanol masers
and their associated ultra-compact HII regions. The spectral
resolution was 3.90625kHz and the continuum sensitivity reached
45µJy/beam. We mapped 372 methanol masers with peak flux densities
of more than 2Jy selected from the literature. Absolute positions have
nominal uncertainties of 0.3". In this first paper on the data
analysis, we present three catalogs; the first gives information on
the strongest feature of 367 methanol maser sources, and the second
provides information on all detected maser spots. The third catalog
presents derived data of the 127 radio continuum counterparts
associated with maser sources. Our detection rate of radio continuum
counterparts toward methanol masers is approximately one-third. Our
catalogs list properties including distance, flux density, luminosity,
and the distribution in the Galactic plane. We found no significant
relationship between luminosities of masers and their associated radio
continuum counterparts, however, the detection rate of radio continuum
emission toward maser sources increases statistically with the maser
luminosities.
Description:
372 unique targets were selected from the following methanol maser
surveys: the Methanol Multi-Beam catalog (MMB; Caswell & Breen
2010MNRAS.407.2599C 2010MNRAS.407.2599C; Green+ 2010-2012, VIII/96), the Arecibo Methanol
Maser Galactic Plane Survey (AMGPS; Pandian+ 2011ApJ...730...55P 2011ApJ...730...55P), the
Torun catalog of 6.7GHz methanol masers (Szymczak+ 2012, J/AN/333/634),
and other individual observations of known 6.7GHz methanol masers or
MSFRs (Caswell+ 1995MNRAS.272...96C 1995MNRAS.272...96C; Walsh+ 1997, J/MNRAS/291/261;
1998, J/MNRAS/301/640; Xu+ 2008A&A...485..729X 2008A&A...485..729X;
Caswell 2009, J/other/PASA/26.454).
The observations were conducted with the VLA in C-configuration using
five sessions from 2012 February 28 to April 16.
Spectral line data used 2048 channels across 8MHz, yielding a channel
spacing of 3.90625kHz at the central frequency of 6.6685192GHz and a
velocity resolution of 0.176km/s. The continuum observations employed
two 1GHz sub-bands from 4.9840 to 6.0080GHz (the low band) and from
6.6245 to 7.6485GHz (the high band) and each sub-band was divided into
16 channels.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 43 33 Non-detection sources
table3.dat 86 367 6.7GHz methanol maser catalog (corrected
version from the author)
table4.dat 86 8971 The maser spots catalog (corrected version
from the author)
table5.dat 85 279 Catalog of radio continuum counterpart of
maser sources
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See also:
VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)
J/MNRAS/446/3461 : 6.7-GHz methanol masers-dust associations (Urquhart+, 2015)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/A+A/563/A130 : GLIMPSE/BGPS 6.7GHz methanol maser survey (Sun+, 2014)
J/other/IJAA/4.571 : Methanol masers in HII regions (Farmer, 2014)
J/MNRAS/435/400 : ATLASGAL. Compact HII regions properties (Urquhart+, 2013)
J/ApJS/205/1 : CORNISH project. II. Source catalog (Purcell+, 2013)
J/A+A/549/A45 : ATLASGAL Compact Source Catalog: 330<l<21 (Contreras+, 2013)
J/AN/333/634 : Torun methanol source catalogue (Szymczak+, 2012)
J/ApJS/194/25 : VLBA calibrator search for the BeSSeL survey (Immer+, 2011)
J/other/PASA/26.454 : Precise positions of methanol masers (Caswell, 2009)
J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/ApJ/656/255 : Arecibo methanol maser Gal. Plane Survey (Pandian+, 2007)
J/A+A/453/1003 : SCUBA ultracompact HII regions (Thompson+, 2006)
J/A+A/403/1095 : 6.7GHz methanol masers survey of YSOs (Minier+, 2003)
J/MNRAS/301/640 : Ultracompact H II regions studies. II. (Walsh+, 1998)
J/MNRAS/291/261 : Methanol maser of IRAS-selected sources (Walsh+ 1997)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Source name (GLLL.ll+B.bb)
15- 16 I2 h RAh Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 26 F6.3 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- 43 A4 --- Ref Reference (1)
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Note (1): References as follows:
C10 = Caswell & Breen (2010MNRAS.407.2599C 2010MNRAS.407.2599C);
G10 = Green et al. (2010MNRAS.409..913G 2010MNRAS.409..913G; see VIII/96);
S14 = Sun et al. (2014, J/A+A/563/A130);
SZ12 = Szymczak et al.(2012, J/AN/333/634);
W97 = Walsh et al. (1997, J/MNRAS/291/261);
X09 = Xu et al. (2009A&A...507.1117X 2009A&A...507.1117X).
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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- 14 A14 --- Name Source name (GLLL.lll+B.bbb)
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 27 F6.3 s RAs Second of Right Ascension (J2000)
29- 29 A1 --- DE- Sign of the Declination (J2000)
30- 31 I2 deg DEd Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 40 F5.2 arcsec DEs Arcsecond of Declination (J2000)
42- 47 F6.2 km/s Vlsr [-70/153] Local Standard of Rest (LSR)
velocity of strongest maser spot
49- 53 F5.2 km/s DelV [0.1/21] Velocity range of maser ΔV
55- 61 F7.2 Jy/beam Spk [0.2/3629] Peak flux density
63- 70 F8.2 Jy Sint [0.4/37475] Integrated flux density
72- 75 F4.1 kpc Dist [0.6/17] Heliocentric distance
77- 79 F3.1 kpc e_Dist [0/3] Uncertainty in Dist
81- 84 F4.2 --- Prob Probability source is at Distance, Dist
(see section 5.2 for details)
86- 86 A1 --- Code Association code between maser source and
the continuum emission (G1)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Source name (GLLL.lll+B.bbb)
16- 17 I2 h RAh Hour of Right Ascension (J2000)
of reference position
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 27 F6.3 s RAs Second of Right Ascension (J2000)
29- 29 A1 --- DE- Sign of the Declination (J2000)
of reference position
30- 31 I2 deg DEd Degree of Declination (J2000)
of reference position
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 40 F5.2 arcsec DEs [0/60] Arcsecond of Declination (J2000)
42- 48 F7.2 km/s Vlsr [-72/159] Radial Velocity of maser spot
50- 56 F7.2 Jy/beam Spk [0.08/3629] Peak Flux of maser spot, Jansky
58- 65 F8.3 arcsec dX X offset to maser spot from reference position
67- 71 F5.3 arcsec e_dX Uncertainty in X offset
73- 80 F8.3 arcsec dY Y offset to maser spot from reference position
82- 86 F5.3 arcsec e_dY Uncertainty in Y offset
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Source name (GLLL.lll+B.bbb)
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs Second of Right Ascension (J2000)
28- 28 A1 --- DE- Sign of the Declination (J2000)
29- 30 I2 deg DEd Degree of Declination (J2000)
32- 33 I2 arcmin DEm Arcminute of Declination (J2000)
35- 38 F4.1 arcsec DEs Arcsecond of Declination (J2000)
40- 46 F7.2 mJy Fint [0.1/9300] Integrated flux of the entire
continuum source
48- 53 F6.2 --- I/P [0.1/562] Ratio of integrated flux to peak
pixel value
55- 59 F5.1 arcsec a Source elliptical shape parameter, a
61- 65 F5.1 arcsec b Source elliptical shape parameter, b
67- 71 F5.1 deg PA Source elliptical shape parameter, position
angle
73- 76 F4.2 pc Offset [0/7] Displacement between peaks of maser and
continuum sources
78- 78 A1 --- l_Diam Limit flag on Diam (1)
79- 83 F5.2 pc Diam [0.01/27] Diameter of the continuum source (2)
85- 85 A1 --- Code Association code between maser source and
the continuum emission (G1)
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Note (1): Upper limits given for the physical diameter of the corresponding
continuum source due to our limited resolving power.
Note (2): Diameter derived from the major axis "a" and the heliocentric
distance of the associated maser.
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Global notes:
Note (G1): Code as follows:
A = associated continuum emission is detected and classified as group A;
B = continuum emission is found in the vicinity of the maser but with
no evidence supporting physical relationship between maser and
continuum source;
N = Absence of continuum emission.
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History:
From electronic version of the journal
2017-Mar-18: Table 3 (correction of declination signs in Names) and
Table 4 (corrections of some spot offsets)
versions sent by the author
2022-Jun-10: Table 3, declination signs corrected (duplication of
declination signs from Table 4)
Acknowledgements:
Bo Hu [Purple Mountain Observatory, Chinese Academy of Science, China]
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Mar-2017