J/MNRAS/483/3146 Young massive stellar objects NH3 mapping (Billington+, 2019)
The RMS survey: Ammonia mapping of the environment of young massive stellar
objects - II.
Billington S.J., Urquhart J.S., Figura C., Eden D.J., Moore T.J.T.
<Mon. Not. R. Astron. Soc., 483, 3146-3167 (2019)>
=2019MNRAS.483.3146B 2019MNRAS.483.3146B (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Radial velocities
Keywords: stars: evolution - stars: massive - ISM: general
Abstract:
We present the results from NH3 mapping observations towards 34
regions identified by the Red MSX Source (RMS) survey. We have used
the Australia Telescope Compact Array to map ammonia (1,1) and (2,2)
inversion emission spectra at a resolution of 10arcsec with velocity
channel resolution of 0.4km/s towards the positions of embedded
massive star formation. Complementary data have been used from the
ATLASGAL and GLIMPSE Legacy Surveys in order to improve the
understanding of the regions and to estimate physical parameters for
the environments. The fields have typical masses of ∼1000M☉,
radii of ∼0.15pc, and distances of ∼3.5kpc. Luminosities range between
∼103 and ∼106L☉ and kinetic temperatures between 10 and 40K.
We classify each field into one of two subsets in order to construct
an evolutionary system for massive star formation in these regions
based on the morphology and relative positions of the NH3 emission,
RMS sources, and ATLASGAL thermal dust emission. Differences in
morphology between NH3 emission and ATLASGAL clumps are shown to
correspond to evolutionary stages of ongoing massive star formation in
these regions. The study has been further refined by including the
positions of known methanol and water masers in the regions to gain
insight into possible protostellar regions and triggered star
formation.
Description:
We have used images from the GLIMPSE Legacy Survey (Benjamin et al.
2003PASP..115..953B 2003PASP..115..953B, Cat. II/293; Churchwell et al.
2009PASP..121..213C 2009PASP..121..213C) in order to investigate the surrounding
environments at mid-infrared wavelengths. Three-colour images have
been created using data at IRAC 3.4, 4.5, and 8µm wavelength bands
from the Spitzer Space Telescope (Fazio et al. 1998SPIE.3354.1024F 1998SPIE.3354.1024F).
The APEX Large Area Survey of the Galaxy (ATLASGAL) survey (Schuller
et al. 2009A&A...504..415S 2009A&A...504..415S; Contreras et al. 2013A&A...549A..45C 2013A&A...549A..45C, Cat.
J/A+A/549/A45; Csengeri et al. 2014A&A...565A..75C 2014A&A...565A..75C, Cat.
J/A+A/565/A75) has surveyed 420deg2 of the Galactic plane, between
-80°=<l=<+60°, and -2°=<b=<+1.5° at 870µm
(345GHz). ATLASGAL has traced dust emission across the Galactic plane
and the compact source catalogue (CSC; Contreras et al.
2013A&A...549A..45C 2013A&A...549A..45C, Cat. J/A+A/549/A45; Urquhart et al.
2014A&A...568A..41U 2014A&A...568A..41U, Cat. J/A+A/568/A41) produced from these maps
consists of ∼10000 compact clumps. The ATLASGAL survey covers 33 out
of 34 of our observed fields. We have used emission contours overlaid
onto the three-colour GLIMPSE images to compare the distribution of
interstellar dust with the integrated ammonia emission and the
mid-infrared environment for each observed field.
Observations were made of the NH3 (1,1) and (2,2) inversion
transitions towards 34 Red MSX Sources (RMS) ientified MYSOs and HII
regions. These observations were made between 2011 February 15 and 22
(Project Id: C2369; Urquhart et al. 2010atnf.prop.3473U). These
observations were conducted using the Australia Telescope National
Facilities' (ATNF) Australia Telescope Compact Array (ATCA). The ATCA
comprises of six 22m diameter antennas, with five lying on a 3km long
east-west track with the sixth antenna being in a fixed position 3km
west of the track.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 39 34 Extracted field parameters from the ATLASGAL
survey
table2.dat 74 34 Observed field parameters
table3.dat 86 44 FellWalker source catalogue for detected clumps
table4.dat 54 44 Table of RMS associations with corresponding
angular offset values for all detected clumps
table6.dat 96 44 Detected NH3 clump parameters
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See also:
J/MNRAS/452/4029 : RMS survey (Urquhart+, 2015)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Field ID
4- 20 A17 --- Name Field Name from the ATLASGAL survey
(GLLL.llll+BB.bbbb)
22- 26 F5.3 [Lsun] Lbol ? Bolometric luminosity of the region
28- 32 F5.3 [Msun] Mfield ? Mass of the region
34- 39 F6.3 [cm-2] NH2 ? H2 column density
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Field ID
4- 20 A17 --- Name Field Name from the ATLASGAL survey
(GLLL.llll+BB.bbbb)
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 32 F5.2 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 45 F5.2 arcsec DEs Declination (J2000)
47 I1 --- NbC Number of clumps
49- 54 F6.1 km/s vLSR Radial velocity relative to local standard of
rest
56- 58 F3.1 kpc Dist Distance
60- 63 F4.2 Jy/beam rms Root mean square (rms) noise
65- 69 F5.2 arcsec Beammaj Beam major axis
71- 74 F4.2 arcsec Beammin Beam minor axis
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Field ID
4- 19 A16 --- Name Clump name derived from the galactic
coordinates of the peak emission of the
source (GLLL.llll+B.bbbb)
21- 22 I2 h RAh Right ascension (J2000)
24- 25 I2 min RAm Right ascension (J2000)
27- 31 F5.2 s RAs Right ascension (J2000)
33 A1 --- DE- Declination sign (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 44 F5.2 arcsec DEs Declination (J2000)
46- 50 F5.2 arcsec sigmaj Semimajor axis of the clump
52- 55 F4.2 arcsec sigmin Semiminor axis of the clump
57- 60 F4.2 --- Aspect Aspect ratio (sigmaj/sigmin)
62- 65 F4.2 pc Rad ? Radius of the clump
67- 73 F7.2 K.km/s Ssum Integrated flux
75- 79 F5.2 K.km/s Speak Peak emission value
81- 86 F6.3 --- SNR Signal to noise ratio
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Field ID
4- 19 A16 --- Name Clump name derived from the galactic
coordinates of the peak emission of the
source (GLLL.llll+B.bbbb)
21- 38 A18 --- OName RMS name (GLLL.llll+BB.bbbb)
40 A1 --- f_OName [*] Flag on OName (1)
42- 51 A10 --- Type RMS type (HII region or YSO)
53- 54 I2 arcsec AOffset Angular offset
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Note (1): Flag as follows:
* = RMS objects deeply embedded within the NH3 clump shown
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Field ID
4- 19 A16 --- Name Clump name derived from the galactic
coordinates of the peak emission of the
source (GLLL.llll+B.bbbb)
21 A1 --- f_Name [*] Flag on Name (1)
23- 29 F7.2 km/s vLSR Radial velocity relative to local standard
of rest
31- 34 F4.2 km/s Deltavpeak Intrinsic FWHM line width of the peak
36- 39 F4.2 km/s Deltavmean Intrinsic FWHM line width median value
41- 44 F4.2 K Texpeak Excitation temperature of the peak
46- 49 F4.2 K Texmean Excitation temperature median value
51- 55 F5.2 K Trotpeak Rotational temperature of the peak (2)
57- 61 F5.2 K Trotmean Rotational temperature median value (2)
63- 67 F5.2 K Tkinpeak Kinetic temperature of the peak
69- 73 F5.2 K Tkinmean Kinetic temperature median value
75- 78 F4.2 --- Bffpeak Beam filling factor of the entire sample of
the peak (3)
80- 83 F4.2 --- Bffmean Median value of the beam filling factor of
the entire sample (3)
85- 89 F5.2 [cm-2] NNH3peak NH3 column density of the peak
91- 96 F6.3 [cm-2] NNH3mean NH3 column density median value
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Note (1): Flag as follows:
* = Identified regions with contain dual spectra components
Note (2): For Tkin<T0=41.5K, the calculation of the rotation temperature can be
completed using the following equation (Walmsley & Ungerechts
1983A&A...122..164W 1983A&A...122..164W; Swift, Welch & Di Francesco 2005ApJ...620..823S 2005ApJ...620..823S):
Trot=Tkin/(1+Tkin/T0ln(1+0.6exp(-15.7/Tkin)))
Note (3): We have used the calculated values of rotational temperature in order
to determine the beam filling factor for the entire sample:
Bff=Tex/Trot
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History:
From electronic version of the journal
Reference:
Urquhart et al.. Paper I 2015MNRAS.452.4029U 2015MNRAS.452.4029U, Cat. J/MNRAS/452/4029
(End) Ana Fiallos [CDS] 27-Jul-2022