J/A+A/610/A27 Compact radio sources in NGC 6334D to F (Medina+, 2018)
Richness of compact radio sources in NGC 6334D to F.
Medina S.-N.X., Dzib S.A., Tapia M., Rodriguez L.F., Loinard L.
<Astron. Astrophys., 610, A27 (2018)>
=2018A&A...610A..27M 2018A&A...610A..27M (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Radio sources ; Photometry, infrared
Keywords: radio continuum: stars - stars: formation -
radiation mechanisms: thermal - radiation mechanisms: non-thermal -
techniques: interferometric
Abstract:
The presence and properties of compact radio sources embedded in
massive star forming regions can reveal important physical properties
about these regions and the processes occurring within them. The
NGC 6334 complex, a massive star forming region, has been studied
extensively. Nevertheless, none of these studies has focused in its
content in compact radio sources. Aims. Our goal here is to report on
a systematic census of the compact radio sources toward NGC 6334, and
their characteristics. This will be used to attempt to define their
very nature.
We used the VLA C band (4-8GHz) archive data with 0.36" (500AU)
of spatial resolution and noise level of 50Jy/bm to carry out a
systematic search for compact radio sources within NGC 6334. We also
searched for infrared counterparts to provide some constraints on the
nature of the detected radio sources.
A total of 83 compact sources and three slightly resolved sources were
detected. Most of them are here reported for the first time. We found
that 29 of these 86 sources have infrared counterparts and three are
highly variable. Region D contains 18 of these sources. The compact
source toward the center, in projection, of region E is also detected.
From statistical analyses, we suggest that the 83 reported compact
sources are real and most of them are related to NGC 6334 itself. A
stellar nature for 27 of them is confirmed by their IR emission.
Compared with Orion, region D suffers a deficit of compact radio
sources. The infrared nebulosities around two of the slightly resolved
sources are suggested to be warm dust, and we argue that the
associated radio sources trace free-free emission from ionized
material. We confirm the thermal radio emission of the compact source
in region E. However, its detection at infrared wavelengths implies
that it is located in the foreground of the molecular cloud. Finally,
three strongly variable sources are suggested to be magnetically
active young stars.
Description:
We have used an archival observation of NGC 6334 obtained with the
Karl G. Jansky Very Large Array (VLA) telescope of the NRAO1 in the
C-band (4 to 8GHz) obtained as part of the project 10C-186. The data
were taken on 7 July 2011, while the array was in A-configuration, its
most extended. Two sub-bands, each 1GHz wide and centered at 5.0 and
7.1GHz, respectively, were recorded simultaneously.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 93 27 Infrared photometry for stellar counterparts of
compact radio sources
table2.dat 116 16 Infrared photometry around the region of
cometary nebulae
tablea1.dat 89 83 Radio properties of compact sources in NGC 6334
--------------------------------------------------------------------------------
See also:
J/ApJS/69/99 : NGC6334 centers of star formation JHK photometry (Straw+ 1989)
J/A+A/316/102 : JHK Photometry in NGC 6334 (Tapia+, 1996)
J/A+A/357/1020 : JHK photometry in NGC 6334 IV (Persi+, 2000)
J/ApJ/707/1 : Water and Methanol masers in NGC 6334I(N) (Brogan+, 2009)
J/A+A/587/A135 : Halpha images of NGC 6334 and NGC 6357 (Russeil+, 2016)
J/A+A/592/A54 : Combined ArTeMiS+SPIRE 350um image of NGC6334 (Andre+, 2016)
J/ApJ/778/96 : Spitzer and NEWFIRM observations of NGC 6334 (Willis+, 2013)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Note [DR] Note (G1)
3- 4 I2 --- ID [1/75] Identification number
6- 10 F5.2 mag Jmag ? 2MASS J magnitude
12- 15 F4.2 mag e_Jmag ? rms uncertainty on Jmag
17- 21 F5.2 mag Hmag ? 2MASS H magnitude
23- 26 F4.2 mag e_Hmag ? rms uncertainty on Hmag
28- 32 F5.2 mag Kmag ? 2MASS K magnitude
34- 37 F4.2 mag e_Kmag ? rms uncertainty on Kmag
39- 43 F5.2 mag [3.6] ? IRAC 3.6um magnitude
45- 48 F4.2 mag e_[3.6] ? rms uncertainty on [3.6]
50- 54 F5.2 mag [4.5] ? IRAC 4.5um magnitude
56- 59 F4.2 mag e_[4.5] ? rms uncertainty on [4.5]
61- 65 F5.2 mag [5.8] ? IRAC 5.8um magnitude
67- 70 F4.2 mag e_[5.8] ? rms uncertainty on [5.8]
72- 75 F4.2 mag [8.0] ? IRAC 8.0um magnitude
77- 80 F4.2 mag e_[8.0] ? rms uncertainty on [8.0]
81- 93 A13 --- Notes Notes (G2)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Note [ab] Note (1)
3- 4 I2 h RAh Right ascension (J2000)
6- 7 I2 min RAm Right ascension (J2000)
9- 13 F5.2 s RAs Right ascension (J2000)
15 A1 --- DE- Declination sign (J2000)
16- 17 I2 deg DEd Declination (J2000)
19- 20 I2 arcmin DEm Declination (J2000)
22- 25 F4.1 arcsec DEs Declination (J2000)
27- 31 F5.2 mag Jmag ? 2MASS J magnitude
33- 36 F4.2 mag e_Jmag ? rms uncertainty on Jmag
38- 42 F5.2 mag Hmag ? 2MASS H magnitude
44- 47 F4.2 mag e_Hmag ? rms uncertainty on Hmag
49- 53 F5.2 mag Kmag ? 2MASS K magnitude
55- 58 F4.2 mag e_Kmag ? rms uncertainty on Kmag
60- 64 F5.2 mag [3.6] ? IRAC 3.6um magnitude
66- 69 F4.2 mag e_[3.6] ? rms uncertainty on [3.6]
71- 75 F5.2 mag [4.5] ? IRAC 4.5um magnitude
77- 80 F4.2 mag e_[4.5] ? rms uncertainty on [4.5]
82- 85 F4.2 mag [5.8] ? IRAC 5.8um magnitude
87- 90 F4.2 mag e_[5.8] ? rms uncertainty on [5.8]
92- 95 F4.2 mag [8.0] ? IRAC 8.0um magnitude
97-100 F4.2 mag e_[8.0] ? rms uncertainty on [8.0]
102-110 A9 --- Notes Notes (G2)
112-116 A5 --- Other Other name
--------------------------------------------------------------------------------
Note (1): Notes as follows:
a = Around VLA J172041.75-354808.2
b = Around VLA J172041.59-354837.3
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Note [RD] Note (G1)
3- 4 I2 --- ID [1/83] Identification number
6- 24 A19 --- VLA VLA name (JHHMMSS.ss+DDMMSS.s)
26- 49 A24 --- OName Other name (2)
51- 53 I3 uJy S6GHz Flux density at 6GHz
55- 56 I2 uJy e_S6GHz rms uncertainty on S6GHz
58 A1 --- l_S5GHz Limit flag on S5GHz (3)
59- 61 I3 uJy S5GHz Flux density at 5GHz
63- 65 I3 uJy e_S5GHz ? rms uncertainty on S5GHz
67 A1 --- l_S7GHz Limit flag on S7GHz (3)
68- 70 I3 uJy S7GHz ? Flux density at 7GHz
72- 74 I3 uJy e_S7GHz ? rms uncertainty on S7GHz
76 A1 --- l_alpha Limit flag on alpha
77- 80 F4.1 --- alpha ? spectral index (Sν∝νalpha)
82- 84 F3.1 --- e_alpha ? rms uncertainty on alpha
86- 89 F4.1 --- S/N Signal-to-noise ratio obtained from
the 6.0GHz map
--------------------------------------------------------------------------------
Note (2): Other names are obtained from the following catalogs:
2MASS = Cutri et al. (2003, Cat. II/246/)
CXOU = Feigelson et al. (2009, Cat. J/AJ/138/227)
[HBM2006b] = Hunter et al. (2006ApJ...649..888H 2006ApJ...649..888H)
CM = Brogan et al. (2016ApJ...832..187B 2016ApJ...832..187B)
SSTU = Willis et al. (2013, Cat. J/ApJ/778/96)
[S2000e] = Sandell (2000A&A...358..242S 2000A&A...358..242S)
[HBC2014] = Hunter et al. (2014ApJ...788..187H 2014ApJ...788..187H)
Note (3): Upper-limits to fluxes are obtained as three times the noise level in
the image, that are at the same time used as the error for these upper-limits.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Note as follows:
D = Sources inside region D
R = Remaining sources
Note (G2): NOtes as follows:
1 = early B spectral type
2 = late B to early A spectral type
3 = late-type
4 = near-IR excess
5 = mid-IR excess
6 = Class II
7 = Class I
8 = 10<AV<28
9 = AV>28
X = X-ray source (Feigelson et al., 2009, Cat. J/AJ/138/227)
CHII-E = C HII region E
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 19-Apr-2018