J/ApJS/181/255 CO in Galactic HII regions (Anderson+, 2009)
The molecular properties of Galactic H II regions.
Anderson L.D., Bania T.M., Jackson J.M., Clemens D.P., Heyer M., Simon R.,
Shah R.Y., Rathborne J.M.
<Astrophys. J. Suppl. Ser., 181, 255-271 (2009)>
=2009ApJS..181..255A 2009ApJS..181..255A
ADC_Keywords: H II regions ; Radio lines ; Interstellar medium
Keywords: H II regions - ISM: clouds - ISM: evolution - ISM: lines and bands -
ISM: structure - radio lines: ISM
Abstract:
We derive the molecular properties for a sample of 301 Galactic HII
regions including 123 ultra compact (UC), 105 compact, and 73 diffuse
nebulae. We analyze all sources within the BU-FCRAO Galactic Ring
Survey (GRS) of 13CO emission known to be HII regions based upon the
presence of radio continuum and cm-wavelength radio recombination line
emission. Unlike all previous large area coverage 13CO surveys, the
GRS is fully sampled in angle and yet covers ∼75deg2 of the Inner
Galaxy. The angular resolution of the GRS (46") allows us to
associate molecular gas with HII regions without ambiguity and to
investigate the physical properties of this molecular gas. We find
clear CO/HII morphological associations in position and velocity for
∼80% of the nebular sample. Compact HII region molecular gas clouds
are on average larger than UC clouds: 2.2' compared to 1.7'.
Description:
We trace these molecular properties of Galactic HII regions using the
13COJ=1->0 emission mapped by the Boston University-Five College
Radio Astronomy Observatory (BU-FCRAO) Galactic Ring Survey (GRS:
Jackson et al. 2006ApJS..163..145J 2006ApJS..163..145J, available at
http://www.bu.edu/galacticring).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 96 301 HII region source sample
table3.dat 89 301 Properties of molecular cloud HII region sources
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See also:
VIII/58 : A Survey of Radio H II Regions in the Northern Sky (Lockman+ 1989)
VII/50 : CO Radial Velocities Toward Galactic H II Regions (Blitz+ 1982)
J/A+A/417/107 : CO velocities in southern HII regions (Russeil+, 2004)
J/ApJ/690/706 : Distances for HII regions (Anderson+, 2009)
http://www.bu.edu/galacticring : BU-FCRAO GRS home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name (ALL.ll+B.bba)
14- 18 F5.2 deg GLON Galactic longitude
20- 24 F5.2 deg GLAT Galactic latitude
26- 27 I2 h RAh Hour of Right Ascension (J2000)
29- 30 I2 min RAm Minute of Right Ascension (J2000)
32- 33 I2 s RAs Second of Right Ascension (J2000)
35 A1 --- DE- Sign of the Declination (J2000)
36- 37 I2 deg DEd Degree of Declination (J2000)
39- 40 I2 arcmin DEm Arcminute of Declination (J2000)
42- 43 I2 arcsec DEs Arcsecond of Declination (J2000)
45- 49 F5.1 km/s VLSR Local Standard of Rest velocity
51- 54 F4.1 km/s e_VLSR Uncertainty in VLSR
56- 71 A16 --- Aut Author's name of the reference
73- 91 A19 --- BibCode Bibcode of the reference
93- 96 A4 --- n_Name Additional comments (1)
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Note (1): Comments as follows:
a = Changed nebular classification from compact;
b = Changed from 19.67-0.14;
c = Changed from 21.44-0.56;
d = Changed from 23.25-0.27;
e = Changed nebular classification from diffuse;
f = Changed from 24.50-0.06;
g = Changed from 25.80-0.14;
h = Changed from 25.95+0.13;
i = Changed from 30.06-0.32;
j = Changed from 30.23-0.15;
k = Changed from 30.51-0.45;
l = Changed from 52.24-0.54.
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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- 12 A12 --- Name Source name (ALL.ll+B.bba)
14- 18 F5.2 deg GLONf ? Fitted ellipse Galactic longitude
20- 24 F5.2 deg GLATf ? Fitted ellipse Galactic latitude
26- 29 F4.1 arcmin Size ? Fitted ellipse size
31- 34 F4.1 arcmin MajAxis ? Fitted ellipse semi-major axis
36- 38 F3.1 arcmin MinAxis ? Fitted ellipse semi-minor axis
40- 44 F5.1 deg PA [-90/+90]? Fitted ellipse position angle
46- 51 F6.2 km/s Vel ? Fitted gaussian velocity
53- 56 F4.2 km/s e_Vel ? The 1σ uncertainty in Vel
58- 62 F5.2 K TMB ? Fitted gaussian brightness temperature
64- 67 F4.2 K e_TMB ? The 1σ uncertainty in TMB
69- 72 F4.2 km/s DelV ? Fitted gaussian FWHM line width
74- 77 F4.2 km/s e_DelV ? The 1σ uncertainty in DelV
79- 82 F4.1 K Tex ? CO excitation temperature
84- 87 F4.1 10+16/cm2 N13CO ? The 13CO column density
89 A1 --- CP [A-E] Nebular confidence parameter (1)
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Note (1): To distinguish sources with an unambiguous molecular gas
component at the HII region position and velocity from those with less
robust molecular gas associations, we assign a confidence parameter
(CP). Qualitative criteria for the confidence parameter are as follows:
A = no ambiguity in position or velocity, the molecular gas coincident with
radio continuum or shows clear signs of interaction;
B = either offset somewhat in position or velocity, or in a complex region of
molecular gas;
C = either offset in position or velocity or in a complex region, but fainter
than a B source and offset further;
D = diffuse emission near the correct position and velocity, but
uncharacterizable due to low intensity or ambiguous morphology;
E = nothing at all apparent in position and velocity.
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History:
From electronic version of the journal
References:
Anderson & Bania. Paper II. 2009ApJ...690..706A 2009ApJ...690..706A Cat. J/ApJ/690/706
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Feb-2011