J/ApJS/219/41 VLA & Chandra obs. of IRAS20126+4104 region (Montes+, 2015)
X-ray and radio observations of the massive star-forming region IRAS 20126+4104.
Montes V.A., Hofner P., Anderson C., Rosero V.
<Astrophys. J. Suppl. Ser., 219, 41 (2015)>
=2015ApJS..219...41M 2015ApJS..219...41M (SIMBAD/NED BibCode)
ADC_Keywords: X-ray sources ; Cross identifications ; Photometry, infrared ;
Radio continuum
Keywords: open clusters and associations: individual: IRAS 20126+4104;
radio continuum: stars; stars: formation; stars: pre-main sequence;
X-rays: stars
Abstract:
We present results from Chandra ACIS-I and Karl G. Jansky Very Large
Array 6cm continuum observations of the IRAS 20126+4104 massive
star-forming region. We detect 150 X-ray sources within the 17'x17'
ACIS-I field, and a total of 13 radio sources within the 9.2' primary
beam at 4.9GHz. Among these observations are the first 6cm detections
of the central sources reported by Hofner et al.
(2007A&A...465..197H 2007A&A...465..197H), namely, I20N1, I20S, and I20var. A new variable
radio source is also reported. Searching the 2MASS archive, we
identified 88 near-infrared (NIR) counterparts to the X-ray sources.
Only four of the X-ray sources had 6cm counterparts. Based on an NIR
color-color analysis and on the Besancon simulation of Galactic
stellar populations, we estimate that approximately 80 X-ray sources
are associated with this massive star-forming region. We detect an
increasing surface density of X-ray sources toward the massive
protostar and infer the presence of a cluster of at least 43 young
stellar objects within a distance of 1.2pc from the massive protostar.
Description:
We observed the IRAS 20126+4104 region with the Chandra ACIS-I
instrument on 2003 March 17 for a total exposure time of 39.35ks.
C-band (6cm) continuum observations of the massive star-forming region
IRAS 20126+4104 were conducted with the VLA operated by NRAO on 2011
August 7.
These data are augmented by NIR and optical archival data. We identify
150 X-ray sources, 88 of which have NIR counterparts. For the Mid-IR
wavelength regions we searched the Spitzer Enhanced Imaging Products
Point Source catalog.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 150 Observed X-ray properties
table4.dat 67 13 Radio sources in the 6cm continuum band
table5.dat 110 105 Multi-wavelength counterparts
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
J/ApJ/685/1005 : Spitzer and high-mass star forming regions (Qiu+, 2008)
J/ApJS/168/100 : X-ray study of star-forming region NGC 6357 (Wang+, 2007)
J/ApJS/163/306 : Chandra study of the Cep B star-forming region (Getman+, 2006)
J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/150] Running sequence number
5- 21 A17 --- CXO CXO name (HHMMSS.s+DDMMSS.s; J2000)
23- 28 F6.3 s RAs [0.4/59.3] Second of right ascension (J2000)
with higher precision
30- 35 F6.3 arcsec DEs [0.8/60] Arcsecond of declination (J2000)
with higher precision
37- 40 F4.2 ct/ks CR [0.2/9.9] Observed count rate
42- 46 F5.2 10-17W/m2 Fx [0.1/13]? Observed X-ray flux;
10-14erg/cm2/s (1)
48- 52 F5.2 --- HR ? Hardness ratio (2)
54- 55 A2 --- Cl Variability classification (V: variable;
FL: flaring; or constant if left blank)
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Note (1): No entry in the Fx column indicates that no acceptable model fit
could be found.
Note (2): The HR is defined as (hx-sx)/(hx+sx) where hx is the
count rate in the 2-8keV energy range and sx is the count rate
between 0.5-2keV. Values of ±1.00 in the HR column thus indicate
that the source was only detected in the hard or soft energy band.
No entry in the hardness ratio column (HR) indicates that the source
was only detected in the full energy range.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- VLA Radio source designation (GLL.llll+B.bbb)
17 A1 --- f_VLA Flag on VLA (1)
19- 20 I2 h RAh Hour of right ascension (J2000)
22- 23 I2 min RAm Minute of right ascension (J2000)
25- 29 F5.2 s RAs Second of right ascension (J2000)
31 A1 --- DE- Sign of declination (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of declination (J2000)
43- 46 F4.1 uJy rms [6/27.1] rms
48- 53 F6.1 uJy Snu [42.4/1682] 6cm flux density
55- 57 A3 --- H07 Radio source in Hofner et al.
2007A&A...465..197H 2007A&A...465..197H (2)
59- 64 A6 --- Rad Radio source in Anderson et al.
2011AJ....142..158A 2011AJ....142..158A (2)
66- 67 I2 --- Seq [30/50]? X-ray counterpart
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Note (1): Flag as follows:
c = Sources located outside the 7.4GHz primary beam. Fluxes were measured
in the 4.9GHz map.
d = Sources located outside the 4.9GHz primary beam. Fluxes were measured
in the 4.9GHz map.
Note (2): Var = Variable source = <[HCO2007] I20var> in Simbad; N1 and S are
<[HCO2007] WN> in Simbad.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/149] Sequence number
5- 21 A17 --- CXO CXO name (HHMMSS.s+DDMMSS.s; J2000)
23- 40 A18 --- 2MASS 2MASS name (HHMMSS.ss+DDMMSS.s; J2000)
42 A1 --- f_2MASS [a-ce-g] Flag on 2MASS (1)
44- 61 A18 --- SSTSLP SSTSLP name (HHMMSS.ss+DDMMSS.s; J2000)
63 A1 --- f_SSTSLP [d] Flag on SSTSLP (1)
65- 79 A15 --- VLA VLA name (GLL.llll+B.bbbb)
81- 92 A12 --- USNO-B1.0 USNO-B1 name
94- 98 F5.2 mag Jmag [8.1/17.9]? 2MASS J-band magnitude
100-104 F5.2 mag Hmag [7.8/17.4]? 2MASS H-band magnitude
106-110 F5.2 mag Ksmag [7.7/16.1]? 2MASS Ks-band magnitude
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Note (1): Flag as follows:
a = Theses sources have in the 2MASS band one or two filter detections with
quality flag U. This means that the source is not detected in this band or
it is detected but not resolved in a consistent fashion with other bands.
The 2MASS data for those sources are not used for the cluster analysis.
b = The majority of the 2MASS counterparts have a quality flag A (high-quality
photometry) in the three bands, except for nine of them. The photometric
quality flags listed for those nine sources, respectively, for the J, H,
and Ks bands: source 15 AAC, source 21 AAB, source 36 AAB, source 41 AAE,
source 55 BAA, source 61 BAC, source 67 AAB, source 78 BAA,
source 111 AEA.
c = Spectral type OB star. Identifiers: HD 228515, ALS 11001, CSI+41-20127 1,
GSC 03155-00985, LS III +41 6, 2MASS J20142661+4112101, TYC 3155-985-1.
d = Same Spitzer counterparts found as in Qiu et al. (2008, J/ApJ/685/1005).
e = Spectral type B star. Identifiers: TYC 3155-859-1, ALS 11003,
CSI+41-20128 2, GSC 03155-00859, LS III +41 7, 2MASS J20143205+4112498.
f = Spectral type F8 star. Identifiers: HD 228527, AG+41 1862, BD+40 4073,
GSC 03155-00817, 2MASS J20143246+4114537, PPM 59547, SAO 49350,
TYC 3155-817-1.
g = Spectral type K5 star. Identifiers: HD 228590, BD+40 4078,
GSC 03159-00721, 2MASS J20151437+4115318, TYC 3159-721-1.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 08-Dec-2015