J/A+A/453/1003 SCUBA ultracompact HII regions (Thompson+, 2006)
A SCUBA imaging survey of ultracompact HII regions.
The environments of massive star formation.
Thompson M.A., Hatchell J., Walsh A.J., Macdonald G.H., Millar T.J.
<Astron. Astrophys., 453, 1003-1026 (2006)>
=2006A&A...453.1003T 2006A&A...453.1003T
ADC_Keywords: H II regions ; Millimetric/submm sources
Keywords: stars: formation - ISM: HII regions - ISM: dust, extinction -
submillimeter - radio continuum: ISM
Abstract:
We present a SCUBA submillimetre (450 and 850µm) survey of the
environment of 105 IRAS point sources, selected from the Wood and
Churchwell (1989ApJS...69..831W 1989ApJS...69..831W) and Kurtz et al. (1994, Cat.
J/ApJS/91/659) radio ultracompact (UC) HII region surveys. We detected
a total of 155 sub-mm clumps associated with the IRAS point sources
and identified three distinct types of object: ultracompact cm-wave
sources that are not associated with any sub-mm emission (sub-mm quiet
objects), sub-mm clumps that are associated with ultracompact cm-wave
sources (radio-loud clumps); and sub-mm clumps that are not associated
with any known ultracompact cm-wave sources (radio-quiet clumps). 90%
of the sample of IRAS point sources were found to be associated with
strong sub-mm emission. We consider the sub-mm colours, morphologies
and distance-scaled fluxes of the sample of sub-mm clumps and show
that the sub-mm quiet objects are unlikely to represent embedded UC
HII regions unless they are located at large heliocentric distances.
Description:
Our observations were carried out using the SCUBA common-user
bolometer array in operation at the James Clerk Maxwell Telescope
(JCMT). The observations were performed in a flexibly-scheduled mode
whereby observations are not scheduled over a pre-defined period but
are carried out over a 6-month observing semester according to the
appropriate weather (atmospheric opacity) band, the visibility of the
sources from the telescope and the scientific priority of the
observations. The survey data were thus obtained by visiting observers
over several separate periods across the 98B (Aug.-Jan.) and 99A
(Feb.-July) observing semesters at the JCMT.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 54 105 UC HII fields observed during the survey, their central
coordinates and estimated distance to the UC HIIs in
each field
refs.dat 144 19 References
table2.dat 105 159 Identifications, coordinates, peak and integrated fluxes
of each submillimetre source detected in the survey
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See also:
J/ApJS/91/659 : Ultracompact HII regions radio images (Kurtz+ 1994)
J/A+A/336/339 : VLA observations of UC HII regions (Molinari+ 1998)
J/A+AS/133/29 : Molecular line survey towards UC HII (Hatchell+ 1998)
J/A+AS/120/283 : Water maser features in UC HII regions (Hofner+ 1996)
J/ApJS/155/123 : JHKs photometry of UC HII regions (Alvarez+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Field UC HII field designation
14 A1 --- n_Field [+] Note on Field (1)
15 A1 --- f_Field [*] Note on Field (2)
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 26 F4.1 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 38 F4.1 arcsec DEs Declination (J2000)
40- 43 F4.1 kpc Dist ?=- Distance or near distance (3)
44 A1 --- --- [/]
45- 48 F4.1 kpc Dist2 ? Far distance (3)
50- 54 A5 --- r_Dist Distance reference
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Note (1): Fields indicated with a dagger (+) show no evidence for UC HII
regions in the Wood & Churchwell (1989ApJS...69..831W 1989ApJS...69..831W) and
Hofner et al. (1994ApJ...429L..85H 1994ApJ...429L..85H) surveys,
or in the literature search described in Sect. 2.1
Note (2): Fields indicated by an asterisk (*) were subject to the 450µm
calibration problems described in Sect. 2.3.
Note (3): In cases where there is an ambiguity between the near and far
kinematic distance both values are listed.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 43 A20 --- Aut Author's name
47-144 A98 --- Com Comments
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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- 13 A13 --- Field UCH II field designation
15 A1 --- m_Field [a-d] Multiplicity index on Field
17- 34 A18 --- Source Source designation (1)
36 A1 --- n_Source [a-e] Note on Source (2)
38- 39 I2 h RAh Right ascension (J2000)
41- 42 I2 min RAm Right ascension (J2000)
44- 47 F4.1 s RAs Right ascension (J2000)
49 A1 --- DE- Declination sign (J2000)
50- 51 I2 deg DEd Declination (J2000)
53- 54 I2 arcmin DEm Declination (J2000)
56- 57 I2 arcsec DEs Declination (J2000)
59 A1 --- l_Fp450um Limit flag on Fp450um (3)
60- 64 F5.1 Jy Fp450um ?=- Peak flux density at 450um (in Jy/beam) (6)
66- 69 F4.1 Jy e_Fp450um ? rms uncertainty in Fp450um (in Jy/beam) (4)
70 A1 --- n_Fp450um [+] Note on Fp450um (5)
72- 75 F4.1 Jy Fp850um ?=- Peak flux density at 850um (in Jy/beam) (6)
77- 79 F3.1 Jy e_Fp850um ? rms uncertainty in Fp850um (in Jy/beam) (4)
81 A1 --- l_Fi450um Limit flag on F450umI (3)
82- 87 F6.1 Jy Fi450um ?=- Integrated flux density at 450um
(in Jy/beam) (6)
89- 93 F5.1 Jy e_Fi450um ? rms uncertainty in F450umI (in Jy/beam) (4)
94 A1 --- n_Fi450um [+] Note on Fi450um (5)
96-100 F5.1 Jy Fi850um ?=- Integrated flux density at 850um
(in Jy/beam) (6)
102-105 F4.1 Jy e_Fi850um ? rms uncertainty in F850umI (in Jy/beam) (4)
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Note (1): All source positions were measured from the 850µm images unless
otherwise stated.
Note (2): Notes as follows:
a = A noisy bolometer clipped from the final rebinned image is
located close to this source and thus the measured flux is a
lower limit to the true flux.
b = These sources are separable in the unsmoothed 450µm image but
blended in the 850µm image. The quoted 850µm flux is
that of the blended single source. The coordinates quoted are
measured from the 450µm image.
c = These sources are separable in the 850µm images but blended
into one source in the smoothed 450µm images. The quoted
450µm flux is the flux of the blended single source.
d = A noisy bolometer clipped from the final rebinned 850µm image
lies over this source and it was not possible to masure any
sensible peak or integrated 850µm flux.
e = This sources lies on the edge of the field of view and thus one
or more of the quoted fluxes is a lower limit to the true flux.
Note (3): Upper limits for non-detections at 450um
Note (4): Quoted errors include calibration uncertainties of 30% at 450µm
and 10% at 850µm.
Note (5): 450µm peak flux measurements indicated by a dagger (+) are
measured from smoothed images and the flux density unit in this
case is Janskys per 14" beam.
The resolution of the unsmoothed images is 8" at 450 µm
and 14" at 850 µm.
Note (6): Where it was not possible to measure a 450µm flux, either due
to the smaller FOV of the short wavelength array or calibration
problems this is indicated by an ellipsis (---).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Jan-2007