J/A+A/652/A12 The new X-Class catalogue (Koulouridis+, 2021)
The X-CLASS survey: A catalogue of 1646 X-ray-selected galaxy clusters
up to z∼1.5.
Koulouridis E., Clerc N., Sadibekova T., Chira M., Drigga E., Faccioli L.,
Le Fevre J.P., Garrel C., Gaynullina E., Gkini A., Kosiba M., Pacaud F.,
Pierre M., Ridl J., Tazhenova K., Adami C., Altieri B., Baguley J.-C.,
Cabanac R., Cucchetti E., Khalikova A., Lieu M., Melin J.-B., Molham M.,
Ramos-Ceja M.E., Soucail G., Takey A., Valtchanov I.
<Astron. Astrophys. 652, A12 (2021)>
=2021A&A...652A..12K 2021A&A...652A..12K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Surveys ; X-ray sources
Keywords: X-rays: galaxies: clusters - galaxies: clusters: general -
surveys - catalogs - large-scale structure of Universe -
galaxies: clusters: intracluster medium
Abstract:
Cosmological probes based on galaxy clusters rely on cluster number
counts and large-scale structure information. X-ray cluster surveys
are well suited for this purpose, since they are far less affected
than optical surveys by projection effects, and cluster properties can
be predicted with good accuracy. The XMM Cluster Archive Super Survey,
X-CLASS, is a serendipitous search of X-ray-detected galaxy clusters
in 4176 XMM-Newton archival observations until August 2015. All
observations are clipped to exposure times of 10 and 20 ks to obtain
uniformity and they span ∼269 sq. deg. across the high-Galactic
latitude sky (|b|>20deg). The main goal of the survey is the
compilation of a well-selected cluster sample suitable for
cosmological analyses. We describe the detection algorithm, the visual
inspection, the verification process and the redshift validation of
the cluster sample, as well as the cluster selection function computed
by simulations. We also present the various metadata that are released
with the catalogue, along with the redshifts of 124 clusters obtained
with a dedicated multi-object spectroscopic follow-up programme. With
this publication we release the new X-CLASS catalogue of 1646
well-selected X-ray-detected clusters over a wide sky area, along with
their selection function. The sample spans a wide redshift range, from
the local Universe up to z∼1.5, with 982 spectroscopically confirmed
clusters, and over 70 clusters above z=0.8. Because of its homogeneous
selection and thorough verification, the cluster sample can be used
for cosmological analyses, but also as a test-bed for the upcoming
eROSITA observations and other current and future large-area cluster
surveys. It is the first time that such a catalogue is made available
to the community via an interactive database which gives access to a
wealth of supplementary information, images, and data.
Description:
SExtractor (Bertin & Arnouts, 1996A&AS..117..393B 1996A&AS..117..393B) was used for source
detection. It provided a centroid estimate, the extent of the X-ray
emission, and a rough measurement of brightness. These parameters
served as input for a maximum likelihood fitting routine that applied
several source models on the photon image in the soft X-ray band: in
particular, a precise point-spread function (PSF) model and an
extended β-model (Cavaliere & Fusco-Femiano,
1978A&A....70..677C 1978A&A....70..677C). We provide two different coordinates and X-ray
count-rate measurements: the pipeline quantities and a more accurate
measurement using a count-rate curve of growth method developed by our
team (Clerc et al., 2012MNRAS.423.3561C 2012MNRAS.423.3561C, Cat. J/MNRAS/423/3561)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 225 1559 The new X-CLASS catalogue (table 3)
tabled1.dat 32 87 X-CLASS clusters classified as 'provisional'
(table D1)
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See also:
J/MNRAS/423/3561 : X-ray clusters from XMM (Clerc+, 2012)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- XClass Cluster name (xclass)
7- 14 F8.4 deg RAdeg Right Ascension (J2000) (pipeline) (ra)
16- 23 F8.4 deg DEdeg Declination (J2000) (pipeline) (dec)
25- 32 F8.4 deg RAmdeg Right Ascension (J2000),
refined measurement (m_ra)
34- 41 F8.4 deg DEmdeg Declination (J2000),
refined measurement (m_dec)
43- 49 F7.4 --- z ? Redshift (redshift)
51- 61 A11 --- f_z Redshift status (status) (1)
63- 74 F12.4 ct Counts Number of counts observed in band B2 0.5-2keV
(total_counts)
76- 85 F10.6 ct/s CR Total count rate observed in band B2 0.5-2keV
(total_rate)
87- 98 F12.4 --- MLdet Detection likelihood DET_ML (emldetect_ml)
100-111 F12.4 --- MLext Extension statistic EXT_LIKE
(emldetectextentml)
113-121 F9.5 arcsec extent [5/447.5] Angular extent EXT (extent)
123-128 F6.3 arcmin offAx [0/12.902] Off-axis distance (off_radius)
130-137 F8.4 ct/s CR1 ? Count-rate measured by the manual profile
fitting in 0.5-2keV band (cr1)
139-144 F6.4 ct/s e_CR1 ? Error of CR1 (errcr1)
146-152 F7.4 ct/s CR2 ? Count-rate measured by the manual profile
fitting in 2-10keV band (cr2)
154-159 F6.4 ct/s e_CR2 ? Error of CR2 (errcr2)
161-167 F7.4 ct/s CR3 ? Count-rate measured by the manual profile
fitting in 0.5-0.9keV band (cr3)
169-174 F6.4 ct/s e_CR3 ? Error of CR3 (errcr3)
176-182 F7.4 ct/s CR4 ? Count-rate measured by the manual profile
fitting in 1.3-2keV band (cr4)
184-189 F6.4 ct/s e_CR4 ? Error of CR4 (errcr4)
191-197 F7.4 ct/s CR5 ? Count-rate measured by the manual profile
fitting in 2-5keV band (cr5)
199-204 F6.4 ct/s e_CR5 ? Error of CR5 (errcr5)
206-212 F7.4 ct/s CR6 ? Count-rate measured by the manual profile
fitting in 5-7keV band (cr6)
214-219 F6.4 ct/s e_CR6 ? Error of CR6 (errcr6)
221-225 F5.1 arcsec rfit [18/775]? Angular cluster radius in which CR
is measured (rfit)
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Note (1): Redshift status: "confirmed" (spectroscopic), "tentative",
"photometric", or "no redshift".
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- XClass Cluster name (xclass)
7- 14 F8.4 deg RAdeg Right Ascension (J2000) (pipeline) (ra)
16- 23 F8.4 deg DEdeg Declination (J2000) (pipeline) (dec)
25- 32 F8.6 ct/s CR Total count rate observed in band B2 0.5-2keV
(total_rate)
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Acknowledgements:
Elias Koulouridis, ekoulouridis(at)noa.gr
(End) Patricia Vannier [CDS] 01-Jun-2021