J/ApJ/756/27 Classification of sources from the 2XMMi-DR3 cat. (Lin+, 2012)
Classification of X-ray sources in the XMM-Newton serendipitous source catalog.
Lin D., Webb N.A., Barret D.
<Astrophys. J., 756, 27 (2012)>
=2012ApJ...756...27L 2012ApJ...756...27L
ADC_Keywords: X-ray sources ; Surveys ; Cross identifications
Keywords: catalogs; infrared: general; X-rays: general
Abstract:
We carry out classification of 4330 X-ray sources in the 2XMMi-DR3
catalog. They are selected under the requirement of being a point
source with multiple XMM-Newton observations and at least one
detection with the signal-to-noise ratio larger than 20. For about
one-third of them we are able to obtain reliable source types from the
literature. They mostly correspond to various types of stars (611),
active galactic nuclei (AGNs, 753), and compact object systems (138)
containing white dwarfs, neutron stars, and stellar-mass black holes.
We find that about 99% of stars can be separated from other source
types based on their low X-ray-to-IR flux ratios and frequent X-ray
flares. AGNs have remarkably similar X-ray spectra, with the power-law
photon index centered around 1.91±0.31, and their 0.2-4.5keV flux
long-term variation factors have a median of 1.48, with 98.5% being
less than 10. In contrast, 70% of compact object systems can be very
soft or hard, highly variable in X-rays, and/or have very large
X-ray-to-IR flux ratios, separating them from AGNs. Using these
results, we derive a source type classification scheme to classify the
other sources and find 644 candidate stars, 1376 candidate AGNs, and
202 candidate compact object systems, whose false identification
probabilities are estimated to be about 1%, 3%, and 18%, respectively.
There are still 320 sources associated with nearby galaxies and 151 in
the Galactic plane, which we expect to be mostly compact object
systems or background AGNs. We also have 100 candidate ultraluminous
X-ray sources. They are found to be much less variable than other
accreting compact objects.
Description:
The 2XMMi-DR3 catalog (Cat. IX/41) is based on 4953 pointed
observations. These observations have a variety of modes of data
acquisition, exposures (>1000s), and optical blocking filters (thick,
medium, and thin). The catalog contains detections in five basic
individual energy bands (0.2-0.5, 0.5-1.0, 1.0-2.0, 2.0-4.5, and
4.5-12.0keV, numbered 1-5, respectively), for each European Photon
Imaging Camera (EPIC), i.e., pn, MOS1/M1, and MOS2/M2. Results are
also given for various combinations of energy bands and cameras. Band
8 refers to the total band 0.2-12.0keV, and EPIC/EP refers to all
cameras.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 185 19637 Source detections and simple fits with
an absorbed power law
table4.dat 538 4330 General source properties and source classification
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See also:
B/cb : Cataclysmic Binaries, LMXBs, and related objects (Ritter+, 2013)
B/xmm : XMM-Newton Obs. Log (XMM-Newton Science Operation Center, 2012)
IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)
IX/41 : XMM-Newton Serendipitous Source Catalogue 2XMMi-DR3 (XMM-SSC, 2010)
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
VII/155 : Third Reference Cat. of Bright Galaxies (RC3) (de Vaucouleurs+ 1991)
J/A+A/557/A81 : XMM-LSS field X-ray sources classification (Melnyk+, 2013)
J/A+A/527/A126 : 2XMMi/SDSS DR7 cross-correlation (Pineau+, 2011)
J/ApJS/194/4 : Classification of CCCP X-ray sources (Broos+, 2011)
J/ApJS/192/10 : Chandra ACIS survey in 383 nearby galaxies. I. (Liu, 2011)
J/A+A/493/339 : XMM-Newton serendipitous Survey. V. (Watson+, 2009)
J/ApJS/184/138 : XID II: RASS-2MASS cross-association (Haakonsen+, 2009)
J/A+A/480/599 : XMM-Newton survey of M31 centre field (Stiele+, 2008)
J/AJ/133/2495 : Classification of RASS optical counterparts (Dragomir+, 2007)
J/ApJS/157/59 : Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005)
J/ApJ/616/1284 : Automated classification of ROSAT sources (McGlynn+, 2004)
http://xmmssc-www.star.le.ac.uk/Catalogue/xcat_public_2XMMi-DR3.html : XMM
catalogue public pages
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Source [837/262284] Unique source identifier (SRCID)
8- 17 I010 --- Obsno Observation identifier
19- 24 I6 --- detID ? Unique detection ID (1)
26- 33 E8.2 ct/s R1 [0/67.2] R1 MOS1-medium-filter equivalent
count rate in 0.2-0.5 keV
35- 42 E8.2 ct/s e_R1 Error in R1
44- 51 E8.2 ct/s R2 R2 MOS1-medium-filter equivalent count
rate in 0.5-1.0 keV
53- 60 E8.2 ct/s e_R2 Error in R2
62- 69 E8.2 ct/s R3 R3 MOS1-medium-filter equivalent count
rate in 1.0-2.0 keV
71- 78 E8.2 ct/s e_R3 Error in R3
80- 87 E8.2 ct/s R4 R4 MOS1-medium-filter equivalent count
rate in 2.0-4.5 keV
89- 96 E8.2 ct/s e_R4 Error in R4
98-105 E8.2 ct/s R5 R5 MOS1-medium-filter equivalent count
rate in 4.5-12 keV
107-114 E8.2 ct/s e_R5 Error in R5
116-119 F4.1 --- chi2 [0/92]? Reduced χ2 of fit with
absorbed power law (PL)
121-122 I2 --- dof ? Degrees of freedom
124-128 F5.2 10+22/cm2 NH [0/20]? Best-fitting column density
130-134 F5.2 10+22/cm2 b_NH ? Lower 90% confidence bound of NH
136-140 F5.2 10+22/cm2 B_NH ? Upper 90% confidence bound of NH
142-146 F5.2 --- Gamma [-2/10]? Best-fitting PL photon index Γ
148-152 F5.2 --- b_Gamma [-2/10]? Lower 90% confidence bound of Gamma
154-158 F5.2 --- B_Gamma [-2/10]? Upper 90% confidence bound of Gamma
160-167 E8.2 mW/m2 Flux ? Power law fit 0.2-12 keV flux
169-176 E8.2 mW/m2 b_Flux ? Lower 90% confidence bound of Flux
178-185 E8.2 mW/m2 B_Flux ? Upper 90% confidence bound of Flux
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Note (1): For a unique source, the detections are specified by Obsno and
detID (SRCID(detection)), which are "OBS_ID" and "SRCID" in the
2XMMi-DR3 catalog, respectively. "Source" (SRCID) is different from
detID only when several "unique" sources in the 2XMMi-DR3 catalog are
rematched together (see Table 1). When the source has no detection in
the 2XMMi-DR3 catalog for an observation, the corresponding detID is
empty, and the fit was not carried out. There are 17 detections not
used in our study (thus not in this table too), because of large
discrepancy between pn and MOS measurements or large extended radius
used in the 2XMMi-DR3 catalog (causing fake large fluxes).
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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- 6 I6 --- Source [837/262284] Unique source identifier
8- 29 A22 --- 2XMMi 2XMMi-DR3 Source designation
(JHHMMSS.s+DDMMSS)
31- 39 F9.5 deg RAdeg Mean source ICRS right ascension (J2000)
41- 49 F9.5 deg DEdeg Mean source ICRS declination (J2000)
51- 54 F4.1 arcsec ePos [0.1/1.1] Mean error on position
56- 64 F9.5 deg GLON Galactic longitude
66- 74 F9.5 deg GLAT Galactic latitude
76- 80 F5.2 10+22/cm2 nH [0.01/2.1] Leiden/Argentine/Bonn Survey of
Galactic HI column density
82- 83 I2 --- Nobs [2/37] Number of observations
85- 92 F8.2 d Dto Time span of all observations
94- 95 I2 --- Nd [1/36] Number of detections from 2XMMi-DR3
97-104 F8.2 d Dtd Time span of all detections from 2XMMi-DR3
106-110 A5 --- Type Source type (1)
112-112 A1 --- u_Type [AB] The source type category; A=identified,
B=candidate
114-133 A20 --- Ref Reference, mostly on the source type
135-159 A25 --- RefID Source name/designation in the reference
161-179 A19 --- RefType Spectral type and/or object type in the
reference (2)
181-185 A5 --- Char Reasons of classifying it as a compact
object system (3)
187-191 F5.2 [-] X/o ? X-ray-to-optical flux ratio logarithm (4)
193-197 F5.2 [-] X/ir ? X-ray-to-IR flux ratio logarithm (4)
199-203 F5.1 --- Fp/bg ? Maximum ratio of flare peak to persistent
background; 1.0 if from visual inspection
205-214 I010 --- OFp ? Correspoding observation ID of the flare
216-223 E8.2 mW/m2 F14max Maximum flux in 0.2-4.5keV band (erg/cm2/s)
225-232 E8.2 mW/m2 e_F14max Error on F14max
234-243 I010 --- OF14max Corresponding observation ID of F14max
245-252 E8.2 mW/m2 F14min Minimum flux in 0.2-4.5keV band
254-261 E8.2 mW/m2 e_F14min Error on F14min
263-272 I010 --- OF14min Corresponding observation ID of F14min
274-281 F8.2 --- var14 [1/30458] Flux variation factor in
0.2-4.5keV band
283-286 F4.1 --- Svar14 Significance of flux variation
288-295 E8.2 mW/m2 F8max ? Maximum flux in 0.2-12.0keV band
297-304 E8.2 mW/m2 e_F8max ? Error on F8max
306-315 I010 --- OF8max ? Corresponding observation ID of F8max
317-324 E8.2 mW/m2 F8min Minimum flux in 0.2-12.0keV band
326-333 E8.2 mW/m2 e_F8min Error on F8min
335-344 I010 --- OF8min Corresponding observation ID of F8min
346-353 F8.2 --- var8 [1/24121]? Flux variation factor in
0.2-12.0keV band
355-358 F4.1 --- Svar8 ? Significance of flux variation
360-371 A12 --- USNOB1 ? USNO B1.0 Source designation (I/284)
373-376 F4.1 arcsec Dxo [0/59]? Angular separation between the X-ray
position and USNOB1 source
378-382 F5.2 mag B1mag [-0.2/24.8]? USNOB1 B1 magnitude
384-388 F5.2 mag R1mag [0/25.5]? USNOB1 R1 magnitude
390-394 F5.2 mag B2mag [0/25.2]? USNOB1 B2 magnitude
396-400 F5.2 mag R2mag [0/50]? USNOB1 R2 magnitude
402-406 F5.2 mag Imag [0/19.6]? USNOB1 I magnitude
408-408 I1 --- f_USNOB1 ? 1 if the optical match is bad
410-426 A17 --- 2MASS ? 2MASS PSC Source designation (II/246)
428-431 F4.1 arcsec Dxir [0/29]? Angular separation between the X-ray
position and 2MASS PSC source
433-438 F6.3 mag Jmag [-1.5/18.8]? 2MASS J magnitude; 1.2um
440-444 F5.3 mag e_Jmag [0/10]? Mean error on J magnitude
446-451 F6.3 mag Hmag [-1.9/17.8]? 2MASS H magnitude; 1.6um
453-457 F5.3 mag e_Hmag [0/0.7]? Mean error on H magnitude
459-464 F6.3 mag Kmag [-2.1/17]? 2MASS Ks magnitude; 2.2um
466-470 F5.3 mag e_Kmag [0/0.4]? Mean error on Ks magnitude
472-472 I1 --- f_2MASS ? 1 if the IR match is bad
474-488 A15 --- RC3Name ? RC3 Galaxy name
490-498 F9.5 deg RA3deg ? Right ascension (J2000), from RC3 or NED
500-508 F9.5 deg DE3deg ? Declination (J2000), from RC3 or NED
510-516 F7.1 arcsec D3 [0.1/36585]? Angular separation from the
RC3 match
518-521 F4.2 --- rD3 ? Ratio of angular separation to D25
isophote elliptical radius
523-529 F7.3 Mpc Dist [0.05/232.2]? Distance to the galaxy
531-538 E8.2 10-7W Lmax ? Maximum 0.2-12.0 keV luminosity (erg/s)
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Note (1): Source type as follows:
Star = star, probably main-sequence star if TpGrad=A;
PrSt = pre-main-sequence star;
OrVr = Orion variable;
VrSt = variable star (probably eclipsing binary, rotationally variable
or pulsating variable star);
FlSt = flaring star;
Sy1n = narrow-line Seyfert 1;
Sy1 = Seyfert 1;
Sy2 = Seyfert 2;
LIN = low-ionization nuclear emission-line region;
Bla = blazars;
QSO = quasi-stellar object/quasar;
AGN = active galactic nucleus;
G = galaxy;
BHB = black-hole X-ray binary;
Bstr = burster;
aPsr = accretion-powered X-ray pulsar;
rPsr = rotation-powered pulsar;
INS = thermally cooling isolated neutron star;
MGR = magnetar;
CV = cataclysmic variable;
ULX = ultra-luminous X-ray source;
CO = compact object system (containing a
white dwarf/neuton star/stellar-mass black hole);
XGS = candidate non-nuclear extragalactic source;
GPS = source probably in the Galactic plane (|b|≤10 degree);
SNR = supernova remnant;
Mixed = refer to RefType for the detailed type.
Note (2): Refer to the reference and note (1) for the meaning of symbols
Note (3): Compact object system for the following reasons:
S = soft (HR1←0.4, HR2←0.5, HR3←0.7, or HR4←0.8)
H = hard (-0.1<HR3<0.5 and -0.25<HR4<0.1)
V = highly variable V_var(0.2-4.5 keV)>10
R = high X-ray-to-IR flux ratio (log(FX/FIR)>2.5)
E = non-nuclear extra-galactic
G = in the Galactic plane (|b|<10)
L = literature, which includes more source properties such as dips
Note (4): The lower limit is given when there is no optical/IR counterpart.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 14-Mar-2014