J/ApJ/517/282 Atomic carbon observations of H II regions (Huang+, 1999)
Atomic carbon observations of southern hemisphere H II region
Huang M., Bania T.M., Bolatto A., Chamberlin R.A., Ingalls J.G.,
Jackson J.M., Lane A.P., Stark A.A., Wilson R.W., Wright G.A.
<Astrophys. J. 517, 282 (1999)>
=1999ApJ...517..282H 1999ApJ...517..282H
ADC_Keywords: H II regions ; Radio lines
Keywords: H II regions - ISM: atoms - ISM: molecules
Abstract:
We report observations of atomic carbon (C I [3P - 3P0]) for a
sample of 49 southern hemisphere H II regions using the Antarctic
Submillimeter Telescope and Remote Observatory. The sources are
compact and isolated members of the Wilson et al. (1970) H109α
radio recombination line (RRL) catalog. The fourth Galactic quadrant
is well covered by the sample. Atomic carbon emission is detected
toward all of the regions, with multiple C I emission components found
toward most sources. The RRL velocity is used to identify the C I
emission associated with the H II region. We measure the mean velocity
difference between the C I and RRL emission to be 0.8±2.8 km
s-1. Within the measurement errors this is exact agreement in
velocity; we conclude that all H II regions have associated C I
emission. The mean C I line temperature of these components is
2.4±1.8 K, compared with 0.7±0.7 K for the C I emission
components not associated with the H II region. This suggests that C I
intensity is dominated by local heating. The FWHM line width of C I
gas associated with H II regions also is marginally greater than that
found for unassociated gas (6.7±3.0, compared with 4.8±2.4 km
s-1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 113 C I emission properties of the HII regions
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Object name
19- 20 I2 h RAh Right Ascension (B1950)
22- 23 I2 min RAm Right Ascension (B1950)
25- 28 F4.1 s RAs Right Ascension (B1950)
30 A1 --- DE- Declination (B1950)
31- 32 I2 deg DEd Declination (B1950)
34- 35 I2 arcmin DEm Declination (B1950)
37- 38 I2 arcsec DEs Declination (B1950)
40- 45 F6.1 km/s VLSR Local Standard of Rest velocity
48- 50 F3.1 km/s e_VLSR Uncertainty in V-LSR
53- 55 F3.1 K Temp Peak temperature
59- 61 F3.1 K e_Temp Uncertainty in Temp
63- 66 F4.1 km/s FWHM Full Width Half Maximum of the emission line
70- 72 F3.1 km/s e_FWHM Uncertainty in FWHM
74- 77 F4.1 K.km/s Area Line area
81- 83 F3.1 K.km/s e_Area Uncertainty in Area
85- 88 F4.2 K GRMS Residual rms after Gaussian fit subtraction
90- 93 F4.2 K BRMS 1σ rms noise level in the baseline
95- 96 A2 --- n_Name Bn: nth order polynomial baseline removed
98- 99 A2 --- f_Name [orfn] (1)
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Note (1):
o = blended lines make Gaussian fits nonunique
r = emission at reference position contaminating at least one
emission-line component
f = spectrum also contains emission feature too complex to fit
n = polynomial baseline removed
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History:
From ApJ electronic edition
References:
Wilson, T. L., Mezger, P. G., Gardner, F. F., & Milne, D. K. 1970,
A&A, 6, 364 (1970A&A.....6..364W 1970A&A.....6..364W)
(End) Greg Schwarz [AAS] 07-Mar-2000