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J/MNRAS/452/4029                  RMS survey                   (Urquhart+, 2015)

The RMS survey: ammonia mapping of the environment of massive young stellar objects. Urquhart J.S., Figura C.C., Moore T.J.T., Csengeri T., Lumsden S.L., Pillai T., Thompson M.A., Eden D.J., Morgan L.K. <Mon. Not. R. Astron. Soc., 452, 4029-4053 (2015)> =2015MNRAS.452.4029U (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Radio sources ; Infrared sources ; Morphology Keywords: stars: early-type - stars: formation - ISM: molecules - radio lines: ISM Abstract: We present the results of ammonia observations towards 66 massive star forming regions identified by the Red Midcourse Space Experiment Source survey. We have used the Green Bank Telescope and the K-Band Focal Plane Array to map the ammonia (NH3) (1,1) and (2,2) inversion emission at a resolution of 30 arcsec in 8 arcmin regions towards the positions of embedded massive star formation. We have identified a total of 115 distinct clumps, approximately two-thirds of which are associated with an embedded massive young stellar object or compact HII region, while the others are classified as quiescent. There is a strong spatial correlation between the peak NH3 emission and the presence of embedded objects. We derive the spatial distribution of the kinetic gas temperatures, line widths, and NH3 column densities from these maps, and by combining these data with dust emission maps we estimate clump masses, H2 column densities and ammonia abundances. The clumps have typical masses of ∼1000M and radii ∼0.5pc, line widths of ∼2km/s and kinetic temperatures of ∼16-20K. We find no significant difference between the sizes and masses of the star-forming and quiescent subsamples; however, the distribution maps reveal the presence of temperature and line width gradients peaking towards the centre for the star-forming clumps while the quiescent clumps show relatively uniform temperatures and line widths throughout. Virial analysis suggests that the vast majority of clumps are gravitationally bound and are likely to be in a state of global free fall in the absence of strong magnetic fields. The similarities between the properties of the two subsamples suggest that the quiescent clumps are also likely to form massive stars in the future, and therefore provide an excellent opportunity to study the initial conditions of massive pre-stellar and protostellar clumps. Description: Derived clump parameters for clumps associated with compact HII regions and massive YSOs identified by the RMS survey. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 60 66 Observed field parameters table2.dat 82 115 *The FellWalker source catalogue table3.dat 101 115 Detected NH3 clump parameters table4.dat 61 88 Matches between NH3 clumps and RMS sources table6.dat 53 115 Derived clump parameters
Note on table2.dat: The parameters given in this table have been obtained from the higher signal-to-noise NH3 (1,1) integrated emission maps.
See also: J/A+A/461/11 : Radio observations of MYSO candidates (Urquhart+, 2007) J/A+A/474/891 : 13CO observations of YSOs in South Gal. plane (Urquhart+, 2007) J/A+A/487/253 : The RMS survey: 13CO observations of YSOs (Urquhart+ 2008) J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009) J/ApJS/208/11 : The Red MSX Source Survey: massive protostars (Lumsden+, 2013) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Field sequential number 4- 18 A15 --- Field Field name (GLLL.lll+BB.bbb) 20- 21 I2 h RAh Right ascension (J2000) 23- 24 I2 min RAm Right ascension (J2000) 26- 30 F5.2 s RAs Right ascension (J2000) 32 A1 --- DE- Declination sign (J2000) 33- 34 I2 deg DEd Declination (J2000) 36- 37 I2 arcmin DEm Declination (J2000) 39- 42 F4.1 arcsec DEs Declination (J2000) 44- 47 F4.2 K.km/s Map Map sensitivity 49 I1 --- NClump Number of clumps 51- 55 F5.1 km/s VLSR ?=- LSR velocity 57- 60 F4.1 kpc Dist ?=- Distance
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Field sequential number 4- 18 A15 --- Clump Clump name (GLLL.lll+BB.bbb) 20- 21 I2 h RAh Right ascension (J2000) 23- 24 I2 min RAm Right ascension (J2000) 26- 30 F5.2 s RAs Right ascension (J2000) 32 A1 --- DE- Declination sign (J2000) 33- 34 I2 deg DEd Declination (J2000) 36- 37 I2 arcmin DEm Declination (J2000) 39- 42 F4.1 arcsec DEs Declination (J2000) 44- 45 I2 arcsec maj Semi-major axis 47- 48 I2 arcsec min Semi-minor axis 50- 52 I3 deg PA Position angle measured anticlockwise from Galactic north 54- 56 F3.1 --- Aspect Aspect ratio 58- 61 F4.1 arcsec thetaR Effective radius of the source 63- 66 F4.1 K.km/s/beam NH3peak NH3 peak flux density 68- 71 F4.2 K.km/s/beam e_NH3peak rms uncertainty on NH3peak 73- 77 F5.1 K.km/s NH3int NH3 integrated flux density 79- 82 F4.1 --- SNR Signal-to-noise ratio
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Field sequential number 4- 18 A15 --- Clump Clump name (GLLL.lll+BB.bbb) 20- 24 F5.1 km/s VLSR LSR velocity 26- 28 F3.1 km/s DV Intrinsic FWHM line width 30- 32 F3.1 km/s e_DV rms uncertainty on DV 34- 36 F3.1 -- taumain Optical depth of the transition 38- 40 F3.1 -- e_taumain rms uncertainty on taumain 42- 45 F4.1 K Tex Excitation temperature 47- 50 F4.1 K e_Tex rms uncertainty on Tex 52- 55 F4.1 K Trot Rotation temperature 57- 60 F4.1 K e_Trot rms uncertainty on Trot 62- 65 F4.1 K Tkin Kinetic temperature 67- 70 F4.1 K e_Tkin rms uncertainty on Tkin 72- 75 F4.2 --- Bff Beam filling factor (Tex/Trot) 77- 81 F5.2 [cm-2] logN(NH3) NH3 column density measured towards the emission peak 83- 87 F5.2 [cm-2] <logN(NH3)> NH3 column density median value determined over the clump 89- 93 F5.2 [-] log(N(NH3)/N(H2)) ?=- NH3 abundance measured towards the emission peak 95- 99 F5.2 [-] <log(N(NH3)/N(H2))> ? NH3 abundance median value determined over the clump 101 I1 --- Notes [1/3]? Notes (1)
Note (1): Note as follows: 1 = the emission profile appears to arise from a single clump 2 = the emission profile appears to arise from multiple distinct clumps along the line of sight 3 = identifies sources that are associated with broad emission wings, which are themselves indicative of outflow motion
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Field sequential number 4- 18 A15 --- Clump Clump name 20- 37 A18 --- RMS MSX Source Name 39- 42 F4.1 arcsec Offset ?=- Angular offset between RMS and Clump positions 44- 61 A18 --- RMSType RMS source type
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Field sequential number 4- 18 A15 --- Clump Clump name (GLLL.lll+BB.bbb) 20- 22 A3 --- RMS? [yes/no ] RMS association ? 24- 27 F4.1 kpc Dist ?=- Distance 29- 32 F4.2 kpc Rad ?=- Radius 34- 38 F5.2 [cm-2] log(PeakN(H2)) ?=- NH2 peak column density 40- 42 F3.1 [Msun] logMclump ?=- Clump mass 44- 48 F5.2 [Msun] logMvir ?=- Virial mass 50- 53 F4.2 [Lsun] logLbol ?=- Bobometric velocity (1)
Note (1): The bolometric luminosity given is the sum of all RMS sources embedded in each clump.
Acknowledgements: James Urquhart, j.s.urquhart(at)gmail.com
(End) Patricia Vannier [CDS] 14-Mar-2016
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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