J/ApJ/927/185 Surveys of clumps & cores in Cygnus X. II. VLA obs. (Wang+, 2022)
Surveys of clumps, cores, and condensations in Cygnus X.
II. Radio properties of massive dense cores.
Wang Y., Qiu K., Cao Y., Cheng Yu, Liu J., Hu Bo
<Astrophys. J., 927, 185 (2022)>
=2022ApJ...927..185W 2022ApJ...927..185W
ADC_Keywords: Radio continuum; Star Forming Region; H II regions; YSOs;
Infrared sources
Keywords: Radio jets ; Protostars ; Star formation ; H II regions
Abstract:
We have carried out a high-sensitivity and high-resolution radio
continuum study toward a sample of 47 massive dense cores (MDCs) in
the Cygnus X star-forming complex using the Karl G. Jansky Very Large
Array, aiming to detect and characterize the radio emission associated
with star-forming activities down to ∼0.01pc scales. We have detected
64 radio sources within or closely around the FWHMs of the MDCs, of
which 37 are reported for the first time. The majority of the detected
radio sources are associated with dust condensations embedded within
the MDCs, and they are mostly weak and compact. We are able to build
spectral energy distributions for eight sources. Two of them indicate
nonthermal emission and the other six indicate thermal free-free
emission. We have determined that most of the radio sources are
ionized jets or winds originating from massive young stellar objects,
whereas only a few sources are likely to be ultracompact HII regions.
Further quantitative analyses indicate that the radio luminosity of
the detected radio sources increases along the evolution path of the
MDCs.
Description:
The VLA X-Band radio continuum observations (Project code: 16A-301,
PI: Keping Qiu) were made on 2016 June 29 using the VLA. The
observations were carried out in the B configuration with all 27
antennas, which provided a typical angular resolution of ∼0.6",
corresponding to a linear scale of ∼0.004pc at a distance of 1.4kpc.
The observations were set in full polarization mode with two 1GHz
basebands centered at 9.5GHz and 10.5GHz, respectively.
There were a total of 22 observing fields covering 29 massive dense
cores (MDCs). The MDCs not covered were MDC 839 and 1112, the eight
MDCs in DR21, and the eight MDCs in the OB2 association, whose
archival data had similar observational settings. For each observing
field, the on-source integration time was 90s, resulting in a
sensitivity of ∼20uJy/beam.
See Section 3.1.
The VLA K-band radio continuum and spectral line observations (Project
code: 17A-107, PI: Keping Qiu) were made during April and May 2017
using the VLA. The observations were carried out in the D
configuration with all 27 antennas, which provided a typical angular
resolution of ∼4", corresponding to a linear scale of ∼0.02pc at a
distance of 1.4kpc.
The observations were set in full polarization mode with two 1GHz
basebands centered at 22.3GHz and 24.0GHz, respectively.
A total of 33 observing fields were observed, in which two were mosaic
fields, each composed of two single-pointing fields. The entire
sample, except the MDCs in the DR21 and W75N regions, is covered. Each
observing field had an on-source integration time of 20 minutes,
resulting in a continuum sensitivity of ∼15uJy/beam.
See Section 3.2.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 131 47 Physical parameters of the massive dense cores (MDCs)
table3.dat 68 168 Properties of the radio continuum maps
table4.dat 157 169 *Radio sources
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Note on table4.dat: The fitting uncertainties and beam sizes are only
provided by Gaussian fitting or are obtained from the literature.
Direct measurement provides total flux densities, peak flux densities,
equivalent sizes of convolved major- and minor-axis only.
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See also:
V/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)
J/A+A/241/551 : Radio continuum in Cygnus X region (Wendker+ 1991)
J/ApJS/91/659 : Ultracompact HII regions radio images (Kurtz+ 1994)
J/A+AS/132/211 : Interstellar SiO sources (Harju+ 1998)
J/A+A/336/339 : VLA obs. of ultracompact HII regions (Molinari+ 1998)
J/MNRAS/301/640 : Ultracompact H II regions studies. II. (Walsh+, 1998)
J/A+A/465/865 : Masers towards high mass protostellar object (Edris+, 2007)
J/A+A/476/1243 : Millimeter continuum mapping of Cygnus X (Motte+, 2007)
J/A+A/474/911 : 1.3mm and CO(2-1) maps of IRAS 20343+4129 (Palau+, 2007)
J/PASJ/59/1185 : Water maser in galactic IRAS sources (Sunada+, 2007)
J/A+A/461/11 : Radio observations of MYSO candidates (Urquhart+, 2007)
J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)
J/A+A/510/A89 : RMS survey of young massive stars in far-IR (Mottram+, 2010)
J/ApJ/715/310 : Early stages of star formation in IRDCs (Rathborne+, 2010)
J/ApJ/720/679 : Optical spectroscopy in Cygnus X region (Beerer+, 2010)
J/MNRAS/404/661 : Young stellar outflows near-IR imaging (Varricatt+ 2010)
J/MNRAS/418/1689 : Red MSX water maser and ammonia emissions (Urquhart+, 2011)
J/ApJ/727/114 : BLAST 2005: a 10deg2 survey in Cygnus X (Roy+, 2011)
J/ApJ/775/63 : Gould's Belt VLA Survey. I. Ophiuchus complex (Dzib+, 2013)
J/ApJS/208/11 : Red MSX Source Survey: massive protostars (Lumsden+, 2013)
J/MNRAS/435/400 : ATLASGAL. Compact HII regions (Urquhart+, 2013)
J/A+A/570/A1 : Cygnus-X CO & SiO outflows datacubes (Duarte-Cabral+, 2014)
J/AJ/148/11 : Infrared photometry in Cygnus-X (Kryukova+, 2014)
J/AJ/150/191 : IR phot. of YSOs in Cygnus-X DR15 (Rivera-Galvez+, 2015)
J/MNRAS/453/645 : Massive molecular outflows (Maud+, 2015)
J/MNRAS/450/4364 : Extended H2 emission from massive YSOs (Navarete+, 2015)
J/MNRAS/458/3027 : Young and embedded clusters in Cygnus-X (Maia+, 2016)
J/ApJS/227/25 : Deep VLA obs. toward high-mass SFRs (Rosero+, 2016)
J/A+A/599/A139 : ATLASGAL massive clumps dust (Koenig+, 2017)
J/A+A/615/A94 : ALMA massive protocluster gas clumps maps (Fontani+, 2018)
J/A+A/615/A103 : CORNISH project. III. UCHII regions (Kalcheva+, 2018)
J/ApJS/234/8 : YSO jets from UWISH2. IV. Cygnus-X outflows (Makin+, 2018)
J/ApJS/235/3 : Massive outflows and ATLASGAL clumps (Yang+, 2018)
J/ApJS/241/1 : Surveys of clumps & cores in Cygnus X. I. MDCs (Cao+, 2019)
J/MNRAS/482/2681 : Hypercompact HII regions in the Galactic Plane (Yang+, 2019)
J/MNRAS/492/895 : Ultracompact HII regions (de la Fuente+, 2020)
J/A+A/653/A108 : Globules and pillars in Cygnus X (Schneider+, 2021)
J/A+A/664/A88 : LOFAR 148MHz Cygnus X region image (Emig+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- MDC [214/5417] Massive Dense Core identifier
6- 28 A23 --- [CQZ2019] Paper I identifier(s) (Cao+ 2019, J/ApJS/241/1)
30- 40 A11 --- M07 Motte+ 2007, J/A+A/476/1243 identifier(s)
42- 43 I2 h RAh [20] Hour of Right Ascension (J2000)
45- 46 I2 min RAm [19/40] Minute of Right Ascension (J2000)
48- 52 F5.2 s RAs Second of Right Ascension (J2000)
54 A1 --- DE- [+] Sign of declination (J2000)
55- 56 I2 deg DEd [37/42] Degree of Declination (J2000)
58- 59 I2 arcmin DEm Arcminute of Declination (J2000)
61- 64 F4.1 arcsec DEs Arcsecond of Declination (J2000)
66- 70 F5.3 pc Dmaj [0.18/0.6] Major axis of fitted FWHM
72- 76 F5.3 pc Dmin [0.17/0.5] Minor axis of fitted FWHM
78- 82 F5.1 deg PA [0.5/178] Position angle of fitte FWHM
84- 90 F7.2 Msun Mass [15.8/1283] Mass (1)
92- 96 F5.2 K Tdust [14/33.4] Dust temperature (1)
98-104 F7.1 Lsun LFIR [27.4/23522] Far infrared luminosity
106-111 F6.2 Jy F24 [0.03/543]? Spitzer/MIPS 24um flux (2)
113 A1 --- f_F24 [a] a=Flux scaled from MSX 21um flux
115-121 A7 cm-2 NH2 H2 column density
123-129 A7 cm-3 nH2 H2 column-averaged density
131 A1 --- Type Classification according to F24 (3)
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Note (1): Determined with a graybody thermal dust emission model.
Note (2): The 24um fluxes are obtained from the Spitzer Cygnus X Archive
Catalog (Kraemer+ 2010AAS...21541401K & Cygnus-X team 2011;
http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-dd?catalog=cygx_arch)
and the MSX6C Infrared Point Source Catalog (Egan+ 2003AAS...203.5708E 2003AAS...203.5708E
and MSX team 2015;
http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-dd?catalog=msxc6).
Note (3): The detailed definitions are given in Section 5. Code as follows:
N = starless MDC candidate (1 occurrence)
Q = infrared-quiet MDC (27 occurrences)
B = infrared-bright MDC (13 occurrences)
C = an MDC whose 24um flux is contaminated by external sources
and cannot be obtained (6 occurrences)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- MDC [214/5417]? Massive Dense Core identifier
6- 10 A5 --- Reg Region identifier
12- 24 A13 --- Code Project Code of MDC map
26 A1 --- f_Freq [abcdef] Flag on Freq (1)
28- 32 F5.2 GHz Freq [1.4/44] Central map frequency
34 A1 --- f_Bmaj Approximate flag on Bmaj
36- 41 F6.3 arcsec Bmaj [0.04/16] Synthesized beam major axis
43 A1 --- f_Bmin Approximate flag on Bmin
45- 50 F6.3 arcsec Bmin [0.03/13.4] Synthesized beam minor axis
52- 58 F7.2 deg BPA [-176/90]? Synthesized beam position angle
60- 68 E9.3 Jy/beam RMS [6.9e-06/0.0015] RMS of the map
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Note (1): Flag as follows:
a = Combined image of project 14A-092 7083 and 14A-092 9375.
b = Combined image of the C band data in projects AH398, AH549,
AK355, and AM446.
c = Combined image of the X band data in projects AC240, AK355, and AM446.
d = Combined image of the Ku band data in projects AC240, AK355, and AM446.
e = Flux density is interpolated from the original data; the other values
are the averages of the original data.
f = Combined image of project 13A-373 1665 and 13A-373 7871.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- MDC [247/5417] Massive Dense Core identifier (1)
6 A1 --- f_MDC [d] Flag on MDC (2)
8- 10 A3 --- ID Radio source identifier in MDC
12 A1 --- f_ID [ef] Flag on ID (2)
14- 15 I2 h RAh [20] Hour of Right Ascension (J2000)
17- 18 I2 min RAm Minute of Right Ascension (J2000)
20- 25 F6.3 s RAs Second of Right Ascension (J2000)
27 A1 --- DE- [+] Sign of the Declination (J2000)
28- 29 I2 deg DEd [37/42] Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 39 F6.3 arcsec DEs Arcsecond of Declination (J2000)
41- 44 F4.1 GHz Freq [1.4/44] Map frequency
46- 51 F6.3 arcsec Dmaj [0.05/16.3]? Source convolved major-axis
length
53- 57 F5.3 arcsec e_Dmaj [0/9.6]? Uncertainty in Dmaj
59- 64 F6.3 arcsec Dmin [0.04/12]? Source convolved minor-axis length
66- 70 F5.3 arcsec e_Dmin [0/2.5]? Uncertainty in Dmin
72- 75 A4 --- f_Dmaj0 Flag on Dmaj0 (2)
76- 80 F5.3 arcsec Dmaj0 [0.02/6.3]? Source deconvolved major-axis
length
82- 85 F4.2 arcsec e_Dmaj0 [0.01/0.05]? Fitting uncertainty in Dmaj0
87- 90 A4 --- f_Dmin0 Flag on Dminj0 (2)
91- 95 F5.3 arcsec Dmin0 [0.01/5.7]? Source deconvolved minor-axis
length
97- 100 F4.2 arcsec e_Dmin0 [0.01/0.1]? Fitting uncertainty in Dmin0
102- 108 F7.4 mJy Snu [0.04/83] Integrated flux
110- 115 F6.3 mJy/beam SnuPk [0.01/78]? Peak flux density
117- 121 F5.3 mJy/beam e_SnuPk [0/2.6]? Uncertainty in SnuPk
123- 127 F5.3 mJy/beam RMS [0.007/1.5] RMS map noise
129- 141 A13 --- Code VLA Project Code of MDC map
143 A1 --- f_Code [abc] Flag on Code (2)
145 A1 --- Meth Method of parameter determination (3)
147- 149 A3 --- Pos Relative position between source and MDC (4)
151- 153 A3 --- Assoc Source associated with a dust condensation?
155- 157 A3 --- New First time source reported?
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Note (1): According to Cao+ (2021ApJ...918L...4C 2021ApJ...918L...4C).
Note (2): Flag as follows:
d = The radio source is on the edge of the maps and is severely affected
by the noises after beam correction. this may cause large
uncertainties in the measured flux densities.
e = The radio sources are unresolved in the map. Also, 1112-r4 and r5 are
likely to be one radio HH-object
(Rodriguez-Kamenetzky+ 2020MNRAS.496.3128R 2020MNRAS.496.3128R).
f = The radio source is resolved by the observations in Q band A array.
The resolved structure is 0.001 pc and is much smaller than the
focused spacial scale in this work. Here we take them as substructures
instead of individual sources.
? = the source has failed to be deconvolved by the Gaussian fitting
task, IMFIT.
* = source is a point source.
a = AM432 is the data used in Carral+ (1999RMxAA..35...97C 1999RMxAA..35...97C).
Their measured flux density is 1.1±0.1mJy.
b = 13B-210 is the data used in Rosero+ (2016, J/ApJS/227/25).
The K band flux density of 274-r1 (20343+4129A in Rosero+ 2016) is
about 0.917mJy in their work. Only peak intensity of 274-r2
(20343+4129B in Rosero+ 2016) is provided in Rosero+ 2016. We also
find it very weak.
c = Project AG625 is the data used in Neria+ (2010RMxAA..46..253N 2010RMxAA..46..253N).
Their measured flux densities of 327-r1 (VLA 3), 742-r2 (VLA 1),
and 742-r3 (VLA 4) are 0.49±0.04, 0.57±0.05, and 0.09±0.03,
respectively.
Note (3): "G/D/L" means that the measurement is done by Gaussian fitting ("G"),
directly measured within selected contour levels ("D"), or obtained
from the literature ("L"), respectively.
Note (4): "In" or "out" means that the radio source is in or out of the
FWHM area of an MDC, respectively.
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History:
From electronic version of the journal
References:
Cao et al. Paper I. 2019ApJS..241....1C 2019ApJS..241....1C Cat. J/ApJS/241/1
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Jan-2024