J/MNRAS/473/4937 AllWISE ctp to ROSAT/2RXS & XMMSLEW2 catalogs (Salvato+, 2018)
Finding counterparts for all-sky X-ray surveys with NWAY:
a Bayesian algorithm for cross-matching multiple catalogues.
Salvato M., Buchner J., Budavari T., Dwelly T., Merloni A.. Brusa M.,
Rau A., Fotopoulou S., Nandra K.
<Mon. Not. R. Astron. Soc. 473, 4937 (2018)>
=2018MNRAS.473.4937S 2018MNRAS.473.4937S (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Infrared sources ; Radio sources ; X-ray sources
Keywords: methods: data analysis - methods: statistical - catalogues -
virtual observatory tools
Abstract:
We release the AllWISE counterparts and Gaia matches to 106573 and
17665 X-ray sources detected in the ROSAT 2RXS and XMMSL2 surveys with
|b|>15°. These are the brightest X-ray sources in the sky, but
their position uncertainties and the sparse multi-wavelength coverage
until now rendered the identification of their counterparts a
demanding task with uncertain results. New all-sky multi-wavelength
surveys of sufficient depth, like AllWISE and Gaia, and a new Bayesian
statistics based algorithm, NWAY, allow us, for the first time, to
provide reliable counterpart associations.
NWAY extends previous distance and sky density based association
methods and, using one or more priors (e.g. colours, magnitudes),
weights the probability that sources from two or more catalogues are
simultaneously associated on the basis of their observable
characteristics. Here, counterparts have been determined using a
Wide-field Infrared Survey Explorer (WISE) colour-magnitude prior. A
reference sample of 4524 XMM/Chandra and Swift X-ray sources
demonstrates a reliability of 94.7 per cent (2RXS) and 97.4 per cent
(XMMSL2). Combining our results with Chandra-COSMOS data, we propose a
new separation between stars and AGN in the X-ray/WISE flux-magnitude
plane, valid over six orders of magnitude. We also release the NWAY
code and its user manual. NWAY was extensively tested with XMM-COSMOS
data.
Using two different sets of priors, we find an agreement of 96 per
cent and 99 per cent with published Likelihood Ratio methods. Our
results were achieved faster and without any follow-up visual
inspection. With the advent of deep and wide area surveys in X-rays
(e.g. SRG/eROSITA, Athena/WFI) and radio (ASKAP/EMU, LOFAR, APERTIF,
etc.) NWAY will provide a powerful and reliable counterpart
identification tool.
See for all the options the Nway manual at
https://github.com/JohannesBuchner/nway/raw/master/doc/nway-manual.pdf
Description:
AllWISE and GAIA counterparts to the ROSAT/2RXS and XMMSLEW2 with
|b|>15deg. The catalog include primary and secondary counterparts.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
2rxswg.dat 572 132254 Position and photometry for AllWISE and GAIA
counterparts to ROSAT/2RXS with |b|>15deg
xmmslew2.dat 692 19141 Position and photometry for AllWISE and GAIA
counterparts to XMMSLEW2 (release 2.0)
with |b|>15deg
--------------------------------------------------------------------------------
See also:
IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
J/A+A/588/A103 : Second ROSAT all-sky survey source catalog (Boller+, 2016)
IX/53 : XMM-Newton slew survey Source Catalogue, version 2.0
(XMM-SSC, 2017)
II/328 : AllWISE Data Release (Cutri+ 2013)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
https://www.cosmos.esa.int/web/xmm-newton/xmmsl2-ug : XMMSLEW2 Home Page
Byte-by-byte Description of file: 2rxswg.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 A21 --- 2RXS IAU Identifier from Boller et al.
(2016, Cat. J/A+A/588/A103) (2RXS_ID)
23- 42 E20.16 deg RAdeg 2RXS Right ascension (J2000.0) (2RXS_RA)
44- 63 E20.16 deg DEdeg 2RXS Declination (J2000.0) (2RXS_DEC)
65- 84 F20.16 arcsec ePos 2RXS positional error (2RXSeRADEC)
86- 93 F8.2 --- ExiML 2RXS source Detection Likelihood from
Boller et al. (2016, Cat. J/A+A/588/A103)
(2RXS_ExiML)
95-100 F6.4 pix Ext 2RXS source extent from Boller et al.
(2016, Cat. J/A+A/588/A103) (2RXS_Ext)
102-108 F7.2 --- ExtML Probability of the 2RXS source extend from
Boller et al. (2016, Cat. J/A+A/588/A103)
(2RXS_ExtML)
110-123 E14.5 mW/m2 SrcFlux 2RXS flux computed as in Dwelly et al.
(2017MNRAS.469.1065D 2017MNRAS.469.1065D) (2RXSSRCFLUX)
125-138 E14.5 mW/m2 e_SrcFlux 2RXS flux error (2RXSSRCFLUX_ERR)
140-158 A19 --- ALLWISE WISE All-Sky Release Catalogue name from
Cutri et al. (2013, Cat. II/328) (ALLW_ID)
160-170 E11.5 deg RAWdeg AllWISE Right Ascension (J2000.0) (ALLW_RA)
172-182 E11.5 deg DEWdeg AllWISE Declination (J2000.0) (ALLW_DEC)
184-195 F12.10 arcsec ePosW AllWISE positional error (ALLWeRADEC)
197-202 F6.3 mag W1mag ? AllWISE Vega magnitude in the W1 band
(ALLW_w1mpro)
204-209 F6.3 mag W2mag ? AllWISE Vega magnitude in the W2 band
(ALLW_w2mpro)
211-216 F6.3 mag W3mag ? AllWISE Vega magnitude in the W3 band
(ALLW_w3mpro)
218-223 F6.3 mag W4mag ? AllWISE Vega magnitude in the W4 band
(ALLW_w4mpro)
225-230 F6.4 mag e_W1mag ? AllWISE magnitude error in the W1 band
(ALLW_w1sigmpro)
232-237 F6.4 mag e_W2mag ? AllWISE magnitude error in the W2 band
(ALLW_w2sigmpro)
239-244 F6.4 mag e_W3mag ? AllWISE magnitude error in the W3 band
(ALLW_w3sigmpro)
246-251 F6.4 mag e_W4mag ? AllWISE magnitude error in the W4band
(ALLW_w4sigmpro)
253-258 F6.1 --- W1snr ? AllWISE signal to noise ratio in the W1
band (ALLW_w1snr)
260-265 F6.1 --- W2snr ? AllWISE signal to noise ratio in the W2
band (ALLW_w2snr)
267-271 F5.1 --- W3snr ? AllWISE signal to noise ratio in the W3
band (ALLW_w3snr)
273-278 F6.1 --- W4snr ? AllWISE signal to noise ratio in the W4
band (ALLW_w4snr)
280-283 A4 --- Flags ? AllWISE reliability flag from Cutri et al.
(2013, Cat. II/328) (ALLWccflags)
285-296 F12.9 arcsec SepW-2RXS [0/100[ Separation between X-ray source and
AllWISE candidate counterpart
(SeparationALLW2RXS)
298-311 F14.9 --- Distbf Logarithm of ratio between prior and
posterior, from separation, positional
error and number density (dist_bayesfactor)
313-326 E14.6 --- Distpost Distance posterior probability comparing
this association vs. no association
(dist_post)
328-342 F15.10 --- Bias Probability weighting introduced by AllWISE
prior. 1 indicates no change
(biasALLWCOLOURMAG_PIX)
344-357 E14.6 --- psingle Same as dist_post, but weighted by the
AllWISE color-magnitude prior. (p_single)
359-372 E14.6 --- pany For each entry in the X-ray catalogue, the
probability that there is a counterpart
(p_any) (1)
374-384 F11.9 --- pi Relative probability of the match (p_i) (2)
386 I1 --- MatchFlag Quality of the X-ray to WISE association
(match_flag) (3)
388-392 I5 --- GroupID ? Sequencial number for X-ray sources with
more than one possible counterpart
(GroupID) (4)
394-395 I2 --- GroupSize ? Number of possible All-WISE counterparts
for a given X-ray source (GroupSize) (5)
397-412 A16 --- 1RXS ? Source name in the 1RXS catalogues of
Voges et al. (1999, Cat. IX/10) and
Voges et al. (2000, Cat. IX/29)
(1RXS_ID) (6)
414-423 I10 --- 2MASS ? 2MASS Identifier as listed in the AllWISE
catalog (ALLW2MASSID)
425-430 F6.3 mag Jmag ? 2MASS magnitude in the J band, as from
AllWISE catalogue. (ALLWjm_2mass)
432-437 F6.3 mag Hmag ? 2MASS magnitude in the H band, as from
AllWISE catalogue. (ALLWhm_2mass)
439-444 F6.3 mag Kmag ? 2MASS magnitude in the K band, as from
AllWISE catalogue. (ALLWkm_2mass)
446-450 F5.3 mag e_Jmag ? 2MASS magnitude error in the J band as
reported in the AllWISE catalogue
(ALLWjmsig_2mass)
452-456 F5.3 mag e_Hmag ? 2MASS magnitude error in the H band as
reported in the AllWISE catalogue
(ALLWhmsig_2mass)
458-462 F5.3 mag e_Kmag ? 2MASS magnitude error in the K band as
reported in the AllWISE catalogue
(ALLWkmsig_2mass)
464-482 I19 --- Gaia ? Solution ID from the original Gaia DR1
catalogue from Fabricious et al.
(2016, Cat. I/337) (GaiaDR1ID)
484-497 E14.10 deg RAGdeg ? Gaia Right Ascension (J2000) (GaiaDR1RA)
499-512 F14.10 deg DEGdeg ? Gaia Declination (J2000) (GaiaDR1DEC)
514-522 F9.4 mas/yr pmRA ? Proper motion in Right Ascension as
measured by Gaia (pmra)
524-531 F8.3 mas/yr pmDE ? Proper motion in Declination as measured
by Gaia (pmdec)
533-538 F6.3 mas/yr e_pmRA ? Proper motion error in Right Ascension
as measured by Gaia (pmra_error)
540-545 F6.3 mas/yr e_pmDE ? Proper motion error in Declination as
measured by Gaia (pmdec_error)
547-555 E9.4 e-/s ? Gaia G-band mean flux (photgmean_flux)
557-565 E9.4 e-/s e_ ? Gaia G-band mean flux error
(photgmeanfluxerror)
567-572 F6.3 mag <Gmag> ? Gaia mean magnitude (photgmean_mag)
--------------------------------------------------------------------------------
Note (1): The lower pany, the lower is confidence that a reliable counterpart
was found.
Note (2): The pi add up to unity for each X-ray source.
Note (3): MatchFlag as follows:
1 = most probable match, if existing
2 = almost as good solutions
For this work we defined match_flag≡2 if pi/pi(match_flag≡1)>0.5.
A selection of match_flag≡1 select the best counterpart for each X-ray
source.
Note (4): All-WISE sources that are candidate to the same X-ray source have the
same value in this column.The column is blanck if the X-ray source has only
one possible counterpart. A sort on the GroupID value, will rank the first
non-unique match group together, followed by all the rows in the second
non-unique group, etc. All the unique matches are listed last.
Note (5): The column is blanck if the X-ray source has only one possible
counterpart
Note (6): Using this column the spectroscopic information from the follow-up
by eBOSS/SPIDERS, as presented in Dwelly et al. (2017MNRAS.469.1065D 2017MNRAS.469.1065D)
can be found.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: xmmslew2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- XMMSL2 XMMSLew2 identifier (XMMSL2_ID) (8)
24- 41 F18.14 deg RAdeg XMMSLew2 Right ascension (J2000.0)
(XMMSL2_RA)
43- 61 F19.15 deg DEdeg XMMSLew2 Declination (J2000.0) (XMMSL2_DEC)
63- 82 F20.16 arcsec ePos XMMSLew2 2RXS positional error
(XMMSL2eRADEC)
84- 95 F12.6 --- DetMLB8 ? XMMSL2 source Detection Likelihood in
band 8 (XMMSL2DETML_B8) (1)
97-108 F12.6 --- DetMLB7 ? XMMSL2 source Detection Likelihood in
band 7 (XMMSL2DETML_B7) (1)
110-122 F13.6 --- DetMLB6 ? XMMSL2 source Detection Likelihood in
band 6 (XMMSL2DETML_B6) (1)
124-132 F9.6 pix EXTB8 ? XMMSL2 source extent in units of image
pixels, in band 8 (XMMSL2EXTB8) (1)
134-142 F9.6 pix EXTB7 ? XMMSL2 source extent in units of image
pixels, in band 7 (XMMSL2EXTB7) (1)
144-152 F9.6 pix EXTB6 ? XMMSL2 source extent in units of image
pixels, in band 6 (XMMSL2EXTB86) (1)
154-164 F11.6 --- ExtMLB8 ? Probability of the XMMSL2 source extend
in band 8 (XMMSL2ExtML_B8) (1)
166-176 F11.6 --- ExtMLB7 ? Probability of the XMMSL2 source extend
in band 7 (XMMSL2ExtML_B7) (1)
178-188 F11.6 --- ExtMLB6 ? Probability of the XMMSL2 source extend
in band 6 (XMMSL2ExtML_B6) (1)
190-201 F12.8 mW/m2 FluxB8 ? XMMSL2 flux in band 8 (XMMSL2FLUXB8) (1)
203-213 F11.7 mW/m2 FluxB7 ? XMMSL2 flux in band 7 (XMMSL2FLUXB7) (1)
215-226 F12.8 mW/m2 FluxB6 ? XMMSL2 flux in band 6 (XMMSL2FLUXB6) (1)
228-238 F11.8 mW/m2 e_FluxB8 ? XMMSL2 flux error in band 8
(XMMSL2FLUXERR_B8) (1)
240-249 F10.7 mW/m2 e_FluxB7 ? XMMSL2 flux error in band 7
(XMMSL2FLUXERR_B7) (1)
251-261 F11.8 mW/m2 e_FluxB6 ? XMMSL2 flux error in band 6
(XMMSL2FLUXERR_B6) (1)
263-281 A19 --- ALLWISE WISE All-Sky Release Catalogue name from
Cutri et al. (2013) (ALLW_ID)
283-293 F11.7 deg RAWdeg AllWISE Right Ascension (J2000.0) (ALLW_RA)
295-305 F11.7 deg DEWdeg AllWISE Declination (J2000.0) (ALLW_DEC)
307-318 F12.10 arcsec ePosW AllWISE positional error (LLWeRADEC)
320-325 F6.3 mag W1mag ? AllWISE Vega magnitude in the W1 band
(ALLW_w1mpro)
327-332 F6.3 mag W2mag ? AllWISE Vega magnitude in the W2 band
(LLW_w2mpro)
334-339 F6.3 mag W3mag ? AllWISE Vega magnitude in the W3 band
(LLW_w3mpro)
341-346 F6.3 mag W4mag ? AllWISE Vega magnitude in the W4 band
(ALLW_w4mpro)
348-352 F5.3 mag e_W1mag ? AllWISE magnitude error in the W1 band
(ALLW_w1sigmpro)
354-359 F6.4 mag e_W2mag ? AllWISE magnitude error in the W2 band
(ALLW_w2sigmpro)
361-366 F6.4 mag e_W3mag ? AllWISE magnitude error in the W3 band
(ALLW_w3sigmpro)
368-373 F6.4 mag e_W4mag ? AllWISE magnitude error in the W4band
(ALLW_w4sigmpro)
375-380 F6.1 --- W1snr ? AllWISE signal to noise ratio in the W1
band (ALLW_w1snr)
382-387 F6.1 --- W2snr ? AllWISE signal to noise ratio in the W2
band (ALLW_w2snr)
389-394 F6.1 --- W3snr ? AllWISE signal to noise ratio in the W3
band (ALLW_w3snr)
396-401 F6.1 --- W4snr ? AllWISE signal to noise ratio in the W4
band (ALLW_w4snr)
403-406 A4 --- Flags ? AllWISE reliability flag from Cutri et al
2013aa (ALLWccflags)
408-419 F12.9 arcsec SepW-2XMM [0/100] Separation between X-ray source and
AllWISE candidate counterpart
(SeparationALLW2RXS)
421-432 F12.8 --- Distbf Logarithm of ratio between prior and
posterior, from separation, positional
error and number density (dist_bayesfactor)
434-446 E13.6 --- Distpost Distance posterior probability comparing
this association vs. no association
(dist_post)
448-462 F15.10 --- Bias Probability weighting introduced by AllWISE
prior. 1 indicates no change
(biasALLWCOLOURMAG_P)
464-476 E13.6 --- psingle Same as dist_post, but weighted by the
AllWISE color-magnitude prior (p_single)
478-490 E13.6 --- pany For each entry in the X-ray catalogue, the
probability that there is a
counterpart (p_any) (2)
492-502 F11.9 --- pi Relative probability of the match (p_i) (3)
504 I1 --- MatchFlag Quality of the X-ray to WISE association
(match_flag) (4)
506-509 I4 --- GroupID ? Sequencial number for X-ray sources with
more than one possible counterpart
(GroupID) (5)
511 I1 --- GroupSize ? Number of possible All-WISE counterparts
for a given X-ray source (GroupSize) (6)
513-528 A16 --- 1RXS ? Source name in the 1RXS catalogues of
Voges et al. (1999, Cat. IX/10) and
Voges et al. (2000, Cat. IX/29)
(1RXS_ID) (7)
530-545 A16 --- 2MASS ? 2MASS Identifier as listed in the AllWISE
catalog (ALLW2MASSID)
547-552 F6.3 mag Jmag ? 2MASS magnitude in the J band, as from
AllWISE catalogue. (ALLWjm_2mass)
554-559 F6.3 mag Hmag ? 2MASS magnitude in the H band, as from
AllWISE catalogue. (ALLWhm_2mass)
561-566 F6.3 mag Kmag ? 2MASS magnitude in the K band, as from
AllWISE catalogue. (ALLWkm_2mass)
568-572 F5.3 mag e_Jmag ? 2MASS magnitude error in the J band as
reported in the AllWISE catalogue
(ALLWjmsig_2mass)
574-578 F5.3 mag e_Hmag ? 2MASS magnitude error in the h band as
reported in the AllWISE catalogue
(ALLWhmsig_2mass)
580-584 F5.3 mag e_Kmag ? 2MASS magnitude error in the K band as
reported in the AllWISE catalogue
(ALLWkmsig_2mass)
586-604 I19 --- Gaia ? Solution ID from the original Gaia DR1
catalogue from Fabricious et al.
(2016, Cat. I/337) (GaiaDR1ID)
606-619 F14.10 deg RAGdeg ? Gaia Right Ascension (J2000) (GaiaDR1RA)
621-634 F14.10 deg DEGdeg ? Gaia Declination (J2000) (GaiaDR1DEC)
636-644 F9.4 mas/yr pmRA ? Proper motion in Right Ascension as
measured by Gaia (pmra)
646-653 F8.3 mas/yr pmDE ? Proper motion in Declination as measured
by Gaia (pmdec)
655-659 F5.3 mas/yr e_pmRA ? Proper motion error in Right Ascension
as measured by Gaia (pmra_error)
661-665 F5.3 mas/yr e_pmDE ? Proper motion error in Declination as
measured by Gaia (pmdec_error)
667-675 E9.4 e-/s ? Gaia G-band mean flux (photgmean_flux)
677-685 E9.3 e-/s e_ ? Gaia G-band mean flux error
(photgmeanfluxerror)
687-692 F6.3 mag <Gmag> ? Gaia mean magnitude (photgmean_mag)
--------------------------------------------------------------------------------
Note (1): the energy range of the various bands are listed in
https://www.cosmos.esa.int/web/xmm-newton/xmmsl2-ug
Note (2): The lower pany, the lower is confidence that a reliable counterpart
was found.
Note (3): The pi add up to unity for each X-ray source.
Note (4): MatchFlag as follows:
1 = most probable match, if existing
2 = almost as good solutions
For this work we defined match_flag≡2 if pi/pi(match_flag≡1)>0.5.
A selection of match_flag≡1 select the best counterpart for each
X-ray source.
Note (5): All-WISE sources that are candidate to the same X-ray source have the
same value in this column. The column is blanck if the X-ray source has only
one possible counterpart. A sort on the GroupID value, will rank the first
non-unique match group together, followed by all the rows in the
second non-unique group, etc. All the unique matches are listed last.
Note (6): The column is blanck if the X-ray source has only one possible
counterpart.
Note (7): Using this column the spectroscopic information from the follow-up by
eBOSS/SPIDERS, as presented in Dwelly et al. (2017MNRAS.469.1065D 2017MNRAS.469.1065D)
can be found.
Note (8): XMMSLew2 identifier from
https://www.cosmos.esa.int/web/xmm-newton/xmmsl2-ug, Cat. IX/53.
--------------------------------------------------------------------------------
Acknowledgements:
Mara Salvato, mara(at)mpe.mpg.de
(End) Mara Salvato [MPE, Germany], Patricia Vannier [CDS] 08-Jan-2018