J/ApJS/194/9 X-ray star clusters in the Carina complex (Feigelson+, 2011)
X-ray star clusters in the Carina complex.
Feigelson E.D., Getman K.V., Townsley L.K., Broos P.S., Povich M.S.,
Garmire G.P., King R.R., Montmerle T., Preibisch T., Smith N.,
Stassun K.G., Wang J., Wolk S., Zinnecker H.
<Astrophys. J. Suppl. Ser., 194, 9 (2011)>
=2011ApJS..194....9F 2011ApJS..194....9F
ADC_Keywords: Clusters, open ; Associations, stellar ; X-ray sources ; Surveys
Keywords: ISM: individual objects (Carina Nebula) - open clusters and
associations: individual (Trumpler 14, Trumpler 15, Trumpler 16,
Collinder 228, C) - stars: formation - stars: pre-main sequence -
X-rays: stars
Abstract:
The distribution of young stars found in the Chandra Carina Complex
Project (CCCP) is examined for clustering structure. X-ray surveys are
advantageous for identifying young stellar populations compared to
optical and infrared surveys in suffering less contamination from
nebular emission and Galactic field stars. The analysis is based on
smoothed maps of a spatially complete subsample of ∼3000 brighter
X-ray sources classified as Carina members and ∼10000 stars from the
full CCCP sample. The principal known clusters are recovered, and some
additional smaller groups are identified. No rich embedded clusters
are present, although a number of sparse groups are found. The CCCP
reveals considerable complexity in clustering properties.
Description:
The CCCP observations and their analysis are described in detail by
Townsley et al. (2011ApJS..194....1T 2011ApJS..194....1T) and Broos et al. (2011, Cat.
J/ApJS/194/2). Twenty-two overlapping pointings with the Chandra
Advanced CCD Imaging Spectrometer (ACIS), each subtending 17'x17',
were observed. They cover a 1.4deg2 region. The X-ray data are
aligned to the Two Micron All Sky Survey (2MASS)/Hipparcos frame and,
in most cases, source positions have accuracies better than 0.5".
Infrared counterparts are found by positional coincidences with 2MASS,
VLT HAWK-I (Preibisch et al. 2011, Cat. J/ApJS/194/10), and other
published catalogs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 145 24 Principal clusters of X-ray stars in the Carina
star-forming complex (see section 3.1)
table2.dat 47 31 Small groups of X-ray stars outside of major clusters
table3.dat 87 14368 Carina cluster membership
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See also:
J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)
J/ApJS/194/4 : Source classifier for X-ray sources (Broos+, 2011)
J/ApJS/194/5 : Carina OB stars in the CCCP catalog (Gagne+, 2011)
J/ApJS/194/10 : NIR properties of YSO in the CCCP (Preibisch+, 2011)
J/ApJS/194/14 : A Pan-Carina YSO catalog (Povich+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- ClReg CCCP-Cl source identification (1)
4 A1 --- f_ClReg [d] Flag on CCCP-Cl D (1)
6- 7 I2 h RAh ? X-ray Hour of right ascension (J2000) (2)
9- 10 I2 min RAm ? X-ray Minute of right ascension (J2000)
12- 15 F4.1 s RAs ? X-ray Second of right ascension (J2000)
17 A1 --- DE- ? X-ray Sign of the declination (J2000) (2)
18- 19 I2 deg DEd ? X-ray Degree of declination (J2000)
21- 22 I2 arcmin DEm ? X-ray Arcminute of declination (J2000)
24- 25 I2 arcsec DEs ? X-ray Arcsecond of declination (J2000)
27- 28 A2 --- Cntr Contour (3)
30- 33 I4 --- N Star population of the cluster
35- 38 I4 --- Nmed Cluster members for wich Emed is available
40- 43 F4.2 keV Emed Average of the observed median X-ray event
energy statistic
45- 48 F4.2 keV e_Emed Standard deviation of Emed
50- 51 I2 mag AV Visual absorption (4)
53- 74 A22 --- OName Opt/IR cluster identification(s) (5)
76 A1 --- f_OName [s] s: Cluster within the Collinder 228 and
South Pillars region (see section 5.2)
78- 89 A12 --- Star1 First optical dominant star
91-115 A25 --- SpType1 MK spectral type for Star1 (6)
117 A1 --- Fig1 [a-y] Letter which identify Star1 in figure 2
119-130 A12 --- Star2 Second optical dominant star
132-143 A12 --- SpType2 MK spectral type for Star2 (6)
145 A1 --- Fig2 [b-t] Letter which identify Star2 in figure 2
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Note (1): Clusters are numbered 1-20; regions are A, B, C or D, and
have no position. The region D contains stars not assigned to
clusters 1-20 nor regions A-C.
Note (2): The cluster positions represent the surface density peaks; due to
non-spherical distributions, these may not correspond to mean or
median positions of the member stars.
Note (3): Contour counted from the lowest contour in figure 1(b)). For example,
contour "2m" represents the second lowest contour where "m" is
appended when the contour was modified to produce a closed boundary.
Note (4): Visual absorption, AV, can be estimated from the gas column
densities, NH, inferred from <Emed> assuming standard gas-to-dust
ratios (Vuong et al. 2003A&A...408..581V 2003A&A...408..581V). These AV estimates,
ranging from AV∼2 to 10mag, are reported with low precision.
Note (5): Correspondences to previously known optical and near-infrared star
clusters are established visually from maps given by Feinstein
(1995RMxAC...2...57F 1995RMxAC...2...57F) and Smith & Brooks (2008hsf2.book..138S 2008hsf2.book..138S). Note
that Trumpler 16 is divided into seven clusters in our analysis.
Associations with mid-infrared clusters in the South Pillars region
are based on the Spitzer IRAC study of Smith et al.
(2010MNRAS.406..952S 2010MNRAS.406..952S).
Note (6): Spectral type from Gagne et al. (2011, Cat. J/ApJS/194/5) or Simbad.
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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- 2 I2 --- Gp [1/31] CCCP-Gp source identification
4- 5 I2 h RAh X-ray Hour of right ascension (J2000)
7- 8 I2 min RAm X-ray Minute of right ascension (J2000)
10- 13 F4.1 s RAs X-ray Second of right ascension (J2000)
15 A1 --- DE- X-ray Sign of the declination (J2000)
16- 17 I2 deg DEd X-ray Degree of declination (J2000)
19- 20 I2 arcmin DEm X-ray Arcminute of declination (J2000)
22- 23 I2 arcsec DEs X-ray Arcsecond of declination (J2000)
25- 26 I2 --- N Star population of the cluster
28- 29 I2 --- Nmed Cluster members for which Emed is available
31- 34 F4.2 keV Emed ? Average of the observed median X-ray event
energy statistic
36- 39 F4.2 keV e_Emed ? Standard deviation of Emed
41- 43 I3 mag AV ? Visual absorption
45 A1 --- Cluster [ABJLMN] Spitzer cluster identification
47 A1 --- f_Cluster [s] s: Cluster within the Collinder 228 and
South Pillars region (see section 5.2)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- CCCP CCCP source number
(<[BTF2011] CCCP NNNNN> in Simbad)
7- 16 A10 --- Label CCCP source label (1)
18- 35 A18 --- CXOGNC IAU designation (HHMMSS.ss+DDMMSS.s)
37- 46 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
48- 57 F10.6 deg DEdeg Declination in decimal degrees (J2000)
59- 65 F7.1 ct Ncts Net counts
67- 71 F5.2 [ct/s/cm2] Flux2 Log photometric flux in the "total" 0.5-8keV
Chandra band; photons/s/cm2
73- 78 F6.2 keV Emed ?=-99 Median X-ray energy
80- 81 A2 --- Class Source membership class (2)
83- 85 A3 --- ClGp Cluster/Group membership (3)
87 A1 --- Reg [A-D] Large-scale region membership (4)
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Note (1): Source labels identify a CCCP pointing; they do not convey
membership in astrophysical clusters.
Note (2): Class from Broos et al., 2011, Cat. J/ApJS/194/4, as follows:
H0 = ambiguous source;
H1 = probable foreground star;
H2 = probable Carina member;
H3 = probable background star;
H4 = probable extragalactic contaminant.
Note (3): Designations "C1","C2", ..., "C20" refer to the 20 X-ray clusters
in Table 1. Designations "G1", "G2", ..., "G31" refer to the 31 X-ray
groups in Table 2.
Note (4): Designations "A", "B", "C", and "D" refer to the large-scale
X-ray regions in Table 1.
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History:
From electronic version of the journal
References:
Townsley et al. CCCP introduction 2011ApJS..194....1T 2011ApJS..194....1T
Broos et al. CCCP catalog Cat. J/ApJS/194/2
Getman et al. Contamination in X-ray studies 2011ApJS..194....3G 2011ApJS..194....3G
Broos et al. Source classifier Cat. J/ApJS/194/4
Gagne et al. O and B stars Cat. J/ApJS/194/5
Povich et al. Cand. X-ray emitting OB stars Cat. J/ApJS/194/6
Naze et al. O and B stars X-ray properties Cat. J/ApJS/194/7
Parkin et al. QZ Car (HD 93206) 2011ApJS..194....8P 2011ApJS..194....8P
Feigelson et al. X-ray star clusters Cat. J/ApJS/194/9
Preibisch et al. NIR properties of YSO Cat. J/ApJS/194/10
Wang et al. Trumpler 15 Cat. J/ApJS/194/11
Wolk et al. Trumpler 16 Cat. J/ApJS/194/12
Povich et al. Pan-Carina YSO catalog Cat. J/ApJS/194/14
Evans et al. Companions of B stars in Tr 16 2011ApJS..194...13E 2011ApJS..194...13E
Townsley et al. Diffuse X-ray emission Cat. J/ApJS/194/15
Townsley et al. Comparison of diffuse emission 2011ApJS..194...16T 2011ApJS..194...16T
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 26-May-2011