J/AJ/141/123 Molecular clouds associated with HII regions (Azimlu+, 2011)
Study of molecular clouds associated with H II regions.
Azimlu M., Fich M.
<Astron. J., 141, 123 (2011)>
=2011AJ....141..123A 2011AJ....141..123A
ADC_Keywords: H II regions ; Molecular clouds ; Carbon monoxide
Keywords: galaxies: star formation - H II regions - ISM: clouds -
ISM: individual objects: (S104, S149, S152, S175, S192-4, S196, S212,
S288, S305, S307)
Abstract:
The properties of molecular clouds associated with 10 HII regions
were studied using CO observations. We identified 142 dense clumps
within our sample and found that our sources are divided into two
categories: those with clumps that show a power-law size-line-width
relation (Type I) and those that do not show any relation (Type II).
The clumps in the Type I sources have larger power-law indices than
found in previous studies. The clumps in the Type II sources have
larger line widths than do the clumps in the Type I sources.
Description:
The observations were carried out in different stages. In the first
stage from 1998 August to November, we made 7'x7' 12CO(2-1) maps
of S175A, S175B, S192/S193, S196, S212, and S305. The details of these
observations have been described in Paper I (Azimlu et al.,
2009AJ....137.4897A 2009AJ....137.4897A). Pointed observations in 13CO(2-1) on peaks of
identified dense clumps within each region were made from 2005 August
to 2006 February. In this period, we also made a 7'x7' 12CO(2-1)
map of S104 with the same observational settings as in 1998, but due
to the large angular size of this HII region we missed most of the
associated molecular gas in our map. Therefore, we decided to extend
the S104 map to a larger area.
Further observations were made with the new ACSIS system at the JCMT
between 2006 October and 2009 January. We extended the S104 map to a
9'x9' map and made four more 7'x7' 12CO(2-1) maps: around S148/S149,
S152, S288, and S307.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 11 Properties of selected regions
table2.dat 76 141 Physical parameters measured for the entire sample
table3.dat 63 141 Physical parameters calculated for all clumps
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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- 9 A9 --- Region Region name
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 19 I2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 29 I2 arcsec DEs Declination (J2000)
31- 34 F4.2 kpc Dist Distance
36- 39 F4.2 kpc e_Dist rms uncertainty on Dist
41- 45 F5.1 km/s Vlsr LSR velocity
47 I1 arcmin Diam Angular diameter
49- 53 F5.2 pc Diaml Linear diameter
55- 59 A5 ---- SpT Spectral type of exciting star
61 A1 --- r_SpT [abcd] Origin of SpT (1)
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Note (1): Notes as follows:
a = Data about exciting star and distance from
Caplan et al. (2000MNRAS.311..317C 2000MNRAS.311..317C).
b = Data about exciting star and distance from
Russeil et al. (2007, Cat. J/A+A/470/161).
c = Data about exciting star and distance from
Moffat et al. (1979A&AS...38..197M 1979A&AS...38..197M).
d = No exciting star is identified for this HII region. The kinematic distance
is reported here. Note that S196 is close to S192/S193 in position and
velocity and is likely to be at the same distance.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Region Region name
12- 15 A4 --- Clump Clump designation, within the region,
[AF2011] Region CNN in Simbad
17- 18 I2 h RAh Right ascension (J2000) (1)
20- 21 I2 min RAm Right ascension (J2000) (1)
23- 26 F4.1 s RAs Right ascension (J2000) (1)
28 A1 --- DE- Declination sign (J2000) (1)
29- 30 I2 deg DEd Declination (J2000) (1)
32- 33 I2 arcmin DEm Declination (J2000) (1)
35- 39 F5.2 arcsec DEs Declination (J2000) (1)
41- 45 F5.2 pc Re Effective radius
47- 51 F5.3 pc e_Re rms uncertainty on Re
53- 56 F4.1 K 12Tb Corrected antenna temperature for 12CO(2-1)
58- 61 F4.1 K 13Tb ?=- Corrected antenna temperature for 13CO(2-1)
63- 69 F7.3 km/s V12 Peak velocity for 12CO(2-1) emission line
71- 76 F6.2 km/s V13 ?=- Peak velocity for 13CO(2-1) emission line
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Note (1): Position of the 12CO(2-1) peak.
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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- 9 A9 --- Region Region name
11- 14 A4 --- Clump Clump designation, within the region
16- 21 F6.3 K Tex Excitation temperature
23- 26 F4.2 km/s DV12 FWHM of the Gaussian best fit to
the 12CO spectra
28- 31 F4.2 km/s DV13 ?=- FWHM of the Gaussian best fit to
the 13CO spectra
33- 38 F6.2 10+20cm-2 NH ?=- Hydrogen column density calculated from
the LTE assumption
40- 44 F5.1 cm-3 nH2 ?=- H2 volume density
46- 49 I4 Msun Mint Velocity-integrated mass
51- 55 F5.1 Msun e_Mint rms uncertainty on Mint
57- 58 I2 --- tau12 ? Calculated optical depth for 12CO
60- 63 F4.2 --- tau13 ? Calculated optical depth for 13CO
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History:
From electronic version of the journal
References:
Azimlu et al., Paper I 2009AJ....137.4897A 2009AJ....137.4897A
(End) Patricia Vannier [CDS] 02-Aug-2012