J/ApJS/209/30 MYStIX project: Bayesian matching (Naylor+, 2013)
Bayesian matching for X-ray and infrared sources in the MYStIX project.
Naylor T., Broos P.S., Feigelson E.D.
<Astrophys. J. Suppl. Ser., 209, 30 (2013)>
=2013ApJS..209...30N 2013ApJS..209...30N
ADC_Keywords: X-ray sources ; Infrared sources ; Cross identifications
Keywords: methods: data analysis - methods: statistical - stars: formation -
stars: pre-main sequence
Abstract:
Identifying the infrared counterparts of X-ray sources in Galactic
plane fields such as those of the MYStIX project presents particular
difficulties due to the high density of infrared sources. This high
stellar density makes it inevitable that a large fraction of X-ray
positions will have a faint field star close to them, which standard
matching techniques may incorrectly take to be the counterpart.
Instead we use the infrared data to create a model of both the field
star and counterpart magnitude distributions, which we then combine
with a Bayesian technique to yield a probability that any star is the
counterpart of an X-ray source. In our more crowded fields, between
10% and 20% of counterparts that would be identified on the grounds of
being the closest star to an X-ray position within a 99% confidence
error circle are instead identified by the Bayesian technique as field
stars. These stars are preferentially concentrated at faint
magnitudes. Equally importantly the technique also gives a probability
that the true counterpart to the X-ray source falls beneath the
magnitude limit of the infrared catalog. In deriving our method, we
place it in the context of other procedures for matching astronomical
catalogs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2a.dat 139 25502 *UKIRT (near-IR) matching results
table2b.dat 110 25502 *Spitzer (mid-IR) matching results
table2.dat 84 20 MYStIX datasets from 2013ApJS..209...26F 2013ApJS..209...26F;
table added by CDS from 2013, ApJS, 209, 26
refs.dat 68 69 References of table2.dat
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Note on table2a.dat and table2b.dat: Tables 2(a) and 2(b) give the NIR and
Spitzer matches, respectively, for all MYStIX fields with these datasets
listed in Table 2 of Feigelson et al. (2013ApJS..209...26F 2013ApJS..209...26F). The tables give
all stars which have a likelihood of being the counterpart of greater than
0.05 (assuming a star falls within our search radius defined above), the
probability that each such star is the counterpart, and the probability there
is no counterpart in the IR catalog.
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJS/209/32 : MYStIX probable young stars (MPCM) (Broos+, 2013)
J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)
J/ApJS/209/29 : MYStIX: MIR observations and catalogs (Kuhn+, 2013)
J/ApJS/209/28 : MYStIX Wide-Field NIR data: crowded fields (King+, 2013)
J/ApJS/209/27 : MYStIX: the Chandra X-ray sources (Kuhn+, 2013)
J/A+A/539/A119 : Pismis 24 stars with X-ray emission (Fang+, 2012)
J/ApJ/753/117 : X-ray catalog of Eagle Nebula (Guarcello+, 2012)
J/ApJ/747/51 : Lagoon Nebula stars. I. Rotation periods (Henderson+, 2012)
J/ApJS/194/14 : A Pan-Carina YSO catalog (Povich+, 2011)
J/ApJS/194/12 : Trumpler 16 in the CCCP (Wolk+, 2011)
J/ApJS/194/11 : Chandra study of Trumpler 15 in Carina (Wang+, 2011)
J/ApJS/194/9 : X-ray star clusters in the Carina complex (Feigelson+, 2011)
J/ApJS/194/6 : Candidate X-ray emitting OB stars in Carina (Povich+, 2011)
J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)
J/ApJ/743/166 : X-ray and infra-red study of RCW 38 (Winston+, 2011)
J/ApJ/743/39 : Spitzer obs. of W3 molecular cloud (Rivera-Ingraham+, 2011)
J/ApJ/733/113 : IRAC observations of IC 1795 (Roccatagliata+, 2011)
J/ApJ/733/50 : MIR phot. monitoring of the ONC (Morales-Calderon+, 2011)
J/A+A/527/A77 : NGC 1893 optical and NIR photometry (Prisinzano+, 2011)
J/A+A/521/A61 : Stars associated to Eagle Nebula (NGC6611) (Guarcello+ 2010)
J/ApJ/725/2485 : X-rays from the star-forming complex W40 (Kuhn+, 2010)
J/ApJ/720/679 : Optical spectroscopy in Cygnus X region (Beerer+, 2010)
J/ApJ/716/474 : The Rosette star-forming complex. III. (Wang+, 2010)
J/MNRAS/407/1170 : IRAC photometry of M8 (Kumar+, 2010)
J/ApJ/707/1 : Water and Methanol masers in NGC 6334I(N) (Brogan+, 2009)
J/ApJ/698/1 : Spitzer observations of NGC 2362 (Currie+, 2009)
J/ApJ/696/1278 : The extended star-forming environment of M17 (Povich+, 2009)
J/ApJ/696/47 : Rosette star-forming complex with Chandra. II. (Wang+, 2009)
J/AJ/138/1116 : A Spitzer view of NGC 2264 (Sung+, 2009)
J/A+A/496/453 : Photometry of candidate members of NGC6611 (Guarcello+, 2009)
J/AJ/138/227 : Stellar clusters in NGC 6334 complex (Feigelson+, 2009)
J/ApJ/675/464 : Chandra observations of NGC 2244 (Wang+, 2008)
J/A+A/488/211 : Infrated photometry of NGC 1893 (Caramazza+, 2008)
J/ApJS/169/353 : Chandra sources in M17 (Broos+, 2007)
J/ApJS/168/100 : X-ray study of star-forming region NGC 6357 (Wang+, 2007)
J/AJ/134/999 : X-ray observations of NGC 2264 (Dahm+, 2007)
J/AJ/133/2072 : Spitzer observations of NGC 2362 (Dahm+, 2007)
J/ApJ/660/1532 : Spitzer/IRAC-MIPS survey of NGC 2244 (Balog+, 2007)
J/ApJ/654/347 : Chandra X-ray observations in Eagle Nebula. I. (Linsky+, 2007)
J/ApJ/654/338 : Spitzer photometry in W3 molecular cloud (Ruch+, 2007)
J/A+A/462/245 : BVI photometry in NGC 6611 (Guarcello+, 2007)
J/ApJ/643/965 : Spitzer photometry of the Trifid nebula (M20) (Rho+, 2006)
J/ApJ/642/972 : IR phot. of a star-forming core in NGC 2264 (Young+, 2006)
J/ApJ/646/269 : Multiwavelength analysis of NGC 2362 (Delgado+, 2006)
J/A+A/460/133 : Chandra X-ray sources in NGC 2362 (Damiani+, 2006)
J/A+A/455/903 : ACIS-I observations of NGC 2264 (Flaccomio+, 2006)
J/AJ/132/1100 : X-ray and IR sources in RCW 38 (Wolk+, 2006)
J/MNRAS/367/513 : JHKs[3.5][4.5] photometry of NGC 3372 (Tapia+, 2006)
J/ApJS/160/319 : COUP: observations and source lists (Getman+, 2005)
J/ApJ/608/781 : NGC 6530 Chandra X-ray catalog (Damiani+, 2004)
J/ApJ/607/904 : Chandra obs. of Trifid nebula (Rho+, 2004)
J/AJ/128/1684 : NGC 2264: VRIHα photometry (Sung+, 2004)
J/AJ/127/2659 : CHANDRA observations of NGC 2264 (Ramirez+, 2004)
J/ApJ/598/375 : Chandra X-ray observations of NGC 2024 (Skinner+, 2003)
Byte-by-byte Description of file: table2a.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- CXO X-ray source name (HHMMSS.ss+DDMMSS.s; J2000)
20- 23 F4.2 --- p.n0 [0/1]?=- Probability that no counterpart
exists in the near-IR catalog
25- 28 F4.2 --- p.n1 [0/1]?=- Probability for the first match
30- 40 F11.7 deg RAn1deg ?=- Right ascension (J2000) for first match
42- 52 F11.7 deg DEn1deg ?=- Declination (J2000) for first match
54- 57 F4.2 --- p.n2 [0/1]?=- Probability for the second match
59- 69 F11.7 deg RAn2deg ?=- Right ascension (J2000) for second match
71- 81 F11.7 deg DEn2deg ?=- Declination (J2000) for second match
83- 86 F4.2 --- p.n3 [0/1]?=- Probability for the third match
88- 98 F11.7 deg RAn3deg ?=- Right ascension (J2000) for third match
100-110 F11.7 deg DEn3deg ?=- Declination (J2000) for third match
112-115 F4.2 --- p.n4 [0/1]?=- Probability for the fourth match
117-127 F11.7 deg RAn4deg ?=- Right ascension (J2000) for fourth match
129-139 F11.7 deg DEn4deg ?=- Declination (J2000) for fourth match
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Byte-by-byte Description of file: table2b.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- CXO X-ray source name (HHMMSS.ss+DDMMSS.s; J2000)
20- 23 F4.2 --- p.m0 [0/1]?=- Probability that no counterpart
exists in the mid-IR catalog
25- 28 F4.2 --- p.m1 [0/1]?=- Probability for the first match
30- 40 F11.7 deg RAm1deg ?=- Right ascension (J2000) for first match
42- 52 F11.7 deg DEm1deg ?=- Declination (J2000) for first match
54- 57 F4.2 --- p.m2 [0/1]?=- Probability for the second match
59- 69 F11.7 deg RAm2deg ?=- Right ascension (J2000) for second match
71- 81 F11.7 deg DEm2deg ?=- Declination (J2000) for second match
83- 86 F4.2 --- p.m3 [0/1]?=- Probability for the third match
88- 98 F11.7 deg RAm3deg ?=- Right ascension (J2000) for third match
100-110 F11.7 deg DEm3deg ?=- Declination (J2000) for third match
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 8 A8 --- Reg Region name
10 A1 --- f_Reg [a-c] Specific data origin(s) (1)
12 I1 --- Np [1/5]? Chandra number of pointings
14- 23 A10 ks Exp Chandra exposure time(s)
25 A1 --- f_Exp [c] Specific exposures (1)
27- 40 A14 --- RefX Chandra principal published studies
reference(s) (see refs.dat file)
42 A1 --- f_RefX [a] Remarks for Orion field (1)
44- 49 A6 --- NIR Near-IR surveys designation (2)
51 A1 --- f_NIR [a-c] Specific near-IR data origin(s) (1)
53- 63 A11 --- MIR MIR Spitzer Space Telescope surveys (3)
65 A1 --- f_MIR [a] Specific mid-IR data origin(s) (1)
67- 84 A18 --- Refs Mid-IR reference(s) (see refs.dat file)
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Note (1): Flag as follows:
a = Chandra Orion Ultradeep Project. X-ray source list and properties
were obtained from Getman et al. (2005, Cat. J/ApJS/160/319). About 22
publications based on the X-ray sources are associated with Getman et al.
(2005, Cat. J/ApJS/160/319) in the 2005 October Special Issue of The
Astrophysical Journal Supplement Series. The near-IR counterparts are
based on deep VLT/ISAAC observations. Mid-IR counterparts are obtained
from the Spitzer survey of Megeath et al. (2012AJ....144..192M 2012AJ....144..192M).
b = X-ray source list and properties were obtained from Kuhn et al. (2010,
Cat. J/ApJ/725/2485). Near-IR counterparts are based on UKIRT
observations.
c = The Carina observations are obtained from the Chandra Carina Complex
Project (Townsley et al. 2011ApJS..194....1T 2011ApJS..194....1T) based on a large mosaic
of Chandra images (Broos et al. 2011, Cat. J/ApJS/194/2), VLT/HAWK-I
near-IR images (Preibisch et al. 2011A&A...530A..34P 2011A&A...530A..34P), and Spitzer IRAC
observations (Povich et al. 2011, Cat. J/ApJS/194/14). The MYStIX field
of view is restricted to the HAWK-I survey field; this is shown in
Figure 5 of Townsley et al. (2011ApJS..194....1T 2011ApJS..194....1T) and Figure 1 of
Preibisch et al. (2011A&A...530A..34P 2011A&A...530A..34P). Chandra exposures overlap
so exposures can vary across a cluster, particularly for Tr 16.
Note (2): Many of these observations were performed by the UKIDSS GPS
surveying 1800deg2 of the Galactic plane (Lawrence et al. 2007, Cat.
II/319; Lucas et al. 2008, Cat. II/316). The remaining fields were
observed with the same UKIRT/WFCAM camera using UKIDSS procedures.
For MYStIX targets inaccessible to UKIRT, and for brighter stars that
are saturated in UKIRT images, we obtained JHK photometry from the
Point Source Catalog of the Two Micron All Sky Survey (2MASS PSC)
obtained with dedicated 1.3m telescopes (Skrutskie 2006, Cat. VII/233).
Note (3): All of the MYStIX star-forming complex targets have Spitzer IRAC
coverage. Five are only covered by the short-exposure Galactic Legacy
Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) project (Benjamin
et al. 2003PASP..115..953B 2003PASP..115..953B). Ten have deeper archived observations
that we analyze as part of the MYStIX effort. For the Carina complex,
we take infrared results published by the Chandra Carina Complex
Project (CCCP; see refs.dat file). For RCW 38 and NGC 3576, the data
are obtained from the Vela-Carina survey (PI: Majewski).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code number
4- 22 A19 --- BibCode Bibcode
24- 46 A23 --- Aut Author's name(s)
48- 68 A21 --- Comm VizieR catalog reference
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History:
From electronic version of the journal
References:
Feigelson et al. Overview. 2013ApJS..209...26F 2013ApJS..209...26F
Kuhn et al. X-ray sources. 2013ApJS..209...27K 2013ApJS..209...27K Cat. J/ApJS/209/27
King et al. Crowded fields. 2013ApJS..209...28K 2013ApJS..209...28K Cat. J/ApJS/209/28
Kuhn et al. MIR. 2013ApJS..209...29K 2013ApJS..209...29K Cat. J/ApJS/209/29
Naylor et al. Bayesian matching. 2013ApJS..209...30N 2013ApJS..209...30N (this paper)
Povich et al. IR excess cat. 2013ApJS..209...31P 2013ApJS..209...31P Cat. J/ApJS/209/31
Broos et al. Young stars. 2013ApJS..209...32B 2013ApJS..209...32B Cat. J/ApJS/209/32
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 09-Jan-2014