J/ApJ/888/118 Chandra and IR study toward IRAS 16562-3959 (Montes+, 2020)
A Chandra X-ray and infrared study of the stellar population in the high-mass
star-forming region IRAS 16562-3959.
Montes V.A., Hofner P., Oskinova L.M., Linz H.
<Astrophys. J., 888, 118-118 (2020)>
=2020ApJ...888..118M 2020ApJ...888..118M (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region; X-ray sources; Photometry, infrared; YSOs
Keywords: Young star clusters; Massive stars; Protostars
Pre-main sequence stars; Star formation; X-ray stars
Abstract:
We present the results from Chandra X-ray observations, and near- and
mid-infrared analysis, using VISTA/VVV and Spitzer/GLIMPSE catalogs,
of the high-mass star-forming region IRAS 16562-3959, which contains a
candidate for a high-mass protostar. We detected 249 X-ray sources
within the ACIS-I field of view. The majority of the X-ray sources
have low count rates (<0.638cts/ks) and hard X-ray spectra. The search
for YSOs in the region using VISTA/VVV and Spitzer/GLIMPSE catalogs
resulted in a total of 636 YSOs, with 74 Class I and 562 Class II
YSOs. The search for near- and mid-infrared counterparts of the X-ray
sources led to a total of 165 VISTA/VVV counterparts, and a total of
151 Spitzer/GLIMPSE counterparts. The infrared analysis of the X-ray
counterparts allowed us to identify an extra 91 Class III YSOs
associated with the region. We conclude that a total of 727 YSOs are
associated with the region, with 74 Class I, 562 Class II, and
91 Class III YSOs. We also found that the region is composed of
16 subclusters. In the vicinity of the high-mass protostar, the
stellar distribution has a core-halo structure. The subcluster
containing the high-mass protostar is the densest and the youngest in
the region, and the high-mass protostar is located at its center. The
YSOs in this cluster appear to be substantially older than the
high-mass protostar.
Description:
The IRAS 16562-3959 high-mass star-forming region was observed with
the Chandra X-Ray Observatory at three different epochs on 2013 Feb 2,
2015 Jun 30 and 2015 Jul 3.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 65 249 X-ray sources
table3.dat 91 98 X-ray properties
table4.dat 109 249 Infrared counterparts
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
II/348 : VISTA Variable in the Via Lactea Survey DR2 (Minniti+, 2017)
II/368 : The Spitzer (SEIP) source list (SSTSL2) (Spitzer Science Center, 2021)
J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005)
J/ApJ/669/493 : Spitzer/Chandra YSOs in Serpens cloud core (Winston+, 2007)
J/ApJS/177/465 : X-ray variability in NGC6946, NGC4485/90 (Fridriksson+, 2008)
J/ApJ/686/1195 : IR photometry in the γ Vel cluster (Hernandez+, 2008)
J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)
J/A+A/534/A131 : Clumps in the giant molecular cloud G345.5+1.0 (Lopez+, 2011)
J/ApJ/743/166 : X-ray and infra-red study of RCW 38 (Winston+, 2011)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
J/A+A/550/A42 : Extinction map towards the Galactic bulge (Chen+, 2013)
J/ApJ/787/108 : Ages for massive SFR stellar populations (Getman+, 2014)
J/ApJ/787/109 : Age estimates for NGC 2024 and ONC stars (Getman+, 2014)
J/ApJS/213/1 : The MSFRs Omnibus X-ray Catalog (MOXC) (Townsley+, 2014)
J/ApJS/219/41 : VLA & Chandra obs. of IRAS20126+4104 region (Montes+, 2015)
J/ApJ/822/49 : Cand. YSOs in AFGL 333 with NEWFIRM & Spitzer (Jose+, 2016)
J/A+A/595/A88 : G345.45+1.50 13CO(3-2) clumps (Lopez-Calderon+, 2016)
J/ApJS/227/25 : 6 & 1.3cm deep VLA obs. toward high-mass SFRs (Rosero+, 2016)
J/A+A/585/A49 : VCNS II. The IR-excess-selected population (Zeidler+, 2016)
J/A+A/615/A148 : Pre-main sequence stars in Scorpius OB1 (Damiani, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/249] Running sequence number
5- 6 I2 h RAh [16/17] Hour of Chandra Right Ascension (J2000)
8- 9 I2 min RAm Minute of Chandra Right Ascension (J2000)
11- 15 F5.2 s RAs Second of Chandra Right Ascension (J2000)
17 A1 --- DE- [-] Sign of the Chandra Declination (J2000)
18- 19 I2 deg DEd [39/40] Degree of Chandra Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Chandra Declination (J2000)
24- 27 F4.1 arcsec DEs Arcsecond of Chandra Declination (J2000)
29- 32 F4.2 ct/ks CR [0.09/5.8] Observed count rate
34- 38 F5.2 10-14mW/m2 Fx [0/12] Observed X-ray flux; 10-14erg/s/cm2
40- 44 F5.2 --- HR [-1/0.93] Hardness ratio (1)
46 I1 --- STVar1 [0/2]? Short Term variability in obs #1
(var if >5) (2)
48 I1 --- STVar2 [0/9]? Short Term variability in obs #2
(var if >5) (2)
50 I1 --- STVar3 [0/9]? Short Term variability in obs #3
(var if >5) (2)
52- 56 F5.2 --- LTVar [0.05/14.1]? Long Term variability parameter
(variable if >3)
58- 65 A8 --- Var Variability type(s) (STV=short term
variability or LTV=long term variability)
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Note (1): Defined as HR=(hx-sx)/(hx+sx) where hx is the count rate in
the 2-8keV energy range, and sx is the count rate in the 0.5-2keV
energy range.
Note (2): Log of observations as below (Table 1):
---------------------------------------------------------------------------
Obs # Chandra ObsID Inst Exposure Date Roll angle
cycle (ks) (deg)
---------------------------------------------------------------------------
1 14 14537 ACIS-I 5.02 2013 Feb 02 95.45
2 16 16658 ACIS-I 38.58 2015 Jun 30 300.22
3 16 17691 ACIS-I 40.07 2015 Jul 03 300.22
---------------------------------------------------------------------------
If the variability index is between 0 and 3, it is unlikely that the
source is variable. If STVar is 4 or 5, the source may be variable,
and if STVar is above 5, the source is definitely variable.
See Section 3.2.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [3/245] Source number
5- 9 F5.2 10+22/cm2 NH [0.2/41.4] Hydrogen column density
11- 15 F5.2 10+22/cm2 E_NH [0.2/31] Upper uncertainty in NH
17- 21 F5.2 10+22/cm2 e_NH [0.17/15] Lower uncertainty in NH
23- 26 F4.2 keV kT [0.29/8.7] Temperature
28 A1 --- f_kT [a] Flag on kT (1)
30- 33 F4.2 keV E_kT [0.5/3.6]? Upper uncertainty in kT
35- 38 F4.2 keV e_kT [0.2/1.8]? Lower uncertainty in kT
40- 45 F6.2 10-5/cm3 EM [0.9/263] Emission measure
47- 52 F6.2 10-5/cm3 E_EM [0.5/850] Upper uncertainty in EM
54- 59 F6.2 10-5/cm3 e_EM [0.45/225] Lower uncertainty in EM
61- 66 F6.2 10-14mW/m2 Fx [1.1/214] Corrected X-ray flux;
in 10-14erg/s/cm2 units
68- 73 F6.2 10-14mW/m2 E_Fx [0.5/130] Upper uncertainty in Fx
75- 80 F6.2 10-14mW/m2 e_Fx [0.5/173] Lower uncertainty in Fx
82- 86 F5.2 [10-7W] logLx [30.5/33] log corrected X-ray luminosity
88- 91 F4.2 --- chi2 [0.01/1.2] Reduced χ2
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Note (1): Flag as follows:
a = The temperature was assumed and frozen for these sources.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/249] Running sequence number
5- 10 F6.3 mag Jmag [9.18/19.8]? J band magnitude
12- 16 F5.3 mag e_Jmag [0.001/0.3]? Uncertainty in Jmag
18- 23 F6.3 mag Hmag [8.7/19.3]? H band magnitude
25- 29 F5.3 mag e_Hmag [0/0.4]? Uncertainty in Hmag
31- 36 F6.3 mag Ksmag [8.7/18.6]? Ks band magnitude
38- 42 F5.3 mag e_Ksmag [0/0.4]? Uncertainty in Ksmag
44- 48 F5.2 mag 3.6mag [7/14.3]? Spitzer/IRAC 3.6 micron band magnitude
50- 53 F4.2 mag e_3.6mag [0.03/0.3]? Uncertainty in 3.6mag
55- 59 F5.2 mag 4.5mag [6.7/14.1]? Spitzer/IRAC 4.5um band magnitude
61- 64 F4.2 mag e_4.5mag [0.03/0.4]? Uncertainty in 4.5mag
66- 70 F5.2 mag 5.8mag [6.5/12.7]? Spitzer/IRAC 5.8um band magnitude
72- 75 F4.2 mag e_5.8mag [0.03/0.4]? Uncertainty in 5.8mag
77- 81 F5.2 mag 8.0mag [6.9/10.9]? Spitzer/IRAC 8.0um band magnitude
83- 86 F4.2 mag e_8.0mag [0.02/0.3]? Uncertainty in 8.0mag
88-109 A22 --- Type Source type
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Jun-2021