J/A+A/551/A8 Galaxy clusters in XMM field within CFHT-LS D4 (de Hoon+, 2013)
Five at one blow. Galaxy clusters in a deep XMM-Newton field within the
CFTHLS D4.
de Hoon A.B.J., Lamer G., Schwope A., Muhlegger M., Fassbender R.,
Boehringer H., Lerchster M., Nastasi A., Suhada R., Brimioulle F.,
Dietrich J.P., Rosati P., Pierini D., Verdugo M., Santos J.S.,
Quintana H., Rabitz A., Takey A.
<Astron. Astrophys. 551, A8 (2013)>
=2013A&A...551A...8D 2013A&A...551A...8D
ADC_Keywords: Clusters, galaxy ; QSOs ; Galaxies, spectra ; Galaxies, optical ;
Galaxies, IR ; Spectral types ; Stars, late-type ; X-ray sources
Keywords: cosmology: observations - dark matter -
large scale structure of universe - X-rays: galaxies: clusters -
surveys
Abstract:
The XMM-Newton Distant Cluster Project (XDCP) aims at the
identification of a well defined sample of X-ray selected clusters of
galaxies at redshifts z>0.8. As part of this project, we analyse the
deep XMM-Newton exposure covering one of the CFHTLS deep fields to
quantify the cluster content. We validate the optical follow-up
strategy as well as the X-ray selection function. We search for
extended X-ray sources in archival XMM-Newton EPIC observations.
Multi-band optical imaging is performed to select high redshift
cluster candidates among the extended X-ray sources.
Here we present a catalogue of the extended sources in one the deepest
LBQS ∼250ks XMM-Newton fields targeting LBQS J2212-1759 covering
∼0.2 square degrees. The cluster identification is based, among
others, on deep imaging with the ESO VLT and from the CFHT legacy
survey. The confirmation of cluster candidates is done by VLT/FORS2
multi-object spectroscopy. Photometric redshifts from the CFHTLS D4
are utilized to confirm the effectiveness of the X-ray cluster
selection method. The survey sensitivity is computed with extensive
Monte-Carlo simulations. At a flux limit of
S(0.5-2.0keV)∼2.5e-15erg/s/cm2 we achieve a completeness level higher
than 50% in an area of ∼0.13 square degrees.
We detect six galaxy clusters above this limit with optical
counterparts, of which 5 are new spectroscopic discoveries. Two newly
discovered X-ray luminous galaxy clusters are at z>1.0, another two at
z=0.41 and one at z=0.34. For the most distant X-ray selected cluster
in this field at z=1.45 we find additional (active) member galaxies
from both X-ray and spectroscopic data. Additionally, we find evidence
of large scale structures at moderate redshifts of z=0.41 and z=0.34.
The quest for distant clusters in archival XMM-Newton data has led to
the detection of six clusters in a single field, making XMM-Newton an
outstanding tool for cluster surveys. Three of these clusters are at
z>1, which emphasises the valuable contribution of small, yet deep
surveys to cosmology. Beta-models are appropriate descriptions for the
cluster surface brightness to perform cluster detection simulations in
order to compute the X-ray selection function. The constructed log
N-log S tends to favour a scenario where no evolution in the cluster
X-ray luminosity function (XLF) takes place.
Description:
The publication discusses the extended source content in the stacked
XMM-Newton observations targeting LBQS J2212-1759. Table "emldet.dat"
presents the complete point source content in the field instead. The
source list is an abbreviated version of the table generated by
emldetect (XMM-SAS task) leaving only the most essential columns
(celestial coordinates, photon counts and flux) in the energy bands
0.5-4.5keV. The details of the source detection are described in
detail in the paper, a method which is similar to Watson et al.,
2009A&A...493..339W 2009A&A...493..339W.
Low resolution spectra recorded with the VLT/FORS2 facility using the
300I and 600I grism have been used to classify over 200 objects within
the CFHT Legacy Survey deep field D4 (observations in 2007 Aug/Sep,
2007Oct/Nov and 2008Jun). A focus has been put on potential cluster
member galaxies of X-ray selected galaxy cluster candidates and on
X-ray point sources. A fraction of late-type stars have received a
spectrum as they were targeted as red galaxies.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
emldet.dat 126 246 X-ray properties of point sources (table2)
speclong.dat 74 231 Object identifications and redshifts (table 5)
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See also:
II/317 : The CFHTLS Survey (T0007 release) (Hudelot+ 2012)
J/A+A/493/339 : XMM-Newton serendipitous Survey. V. (Watson+, 2009)
Byte-by-byte Description of file: emldet.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/246] Running number
6- 9 A4 --- --- [XMMU]
11- 26 A16 --- XMMU Object XMMU name (JHHMMSS.s+DDMMSS)
29- 38 F10.6 deg RAdeg Right ascension (J2000.0)
41- 50 F10.6 deg DEdeg Declination (J2000.0)
53- 59 F7.2 --- Cts Photon counts
62- 66 F5.2 --- e_Cts Photon counts error
71- 80 E10.4 s-1 CRate Photon count rate
83- 92 E10.4 s-1 e_CRate Photon count rate error
95-104 E10.4 mW/m2 Flux Source flux (0.5-4.5keV)
107-116 E10.4 mW/m2 e_Flux Source flux error (0.5-4.5keV)
119-126 F8.2 --- ML Detection likelihood
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Byte-by-byte Description of file: speclong.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/231] Running number
5- 11 A7 --- Name Identifier for cluster member galaxies (1)
13- 14 I2 h RAh Right ascension (J2000.0)
16- 17 I2 min RAm Right ascension (J2000.0)
19- 22 F4.1 s RAs Right ascension (J2000.0)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 34 F4.1 arcsec DEs Declination (J2000)
36- 41 F6.4 --- z Redshift
43 A1 --- f_z [<] Limit flag on e_z
44- 49 F6.4 --- e_z ?=- Error in redshift (1 σ)
51 I1 --- Sf [0/2]? Spectrocopic validity flag, 0=best (2)
53- 60 A8 --- Temp Template used to achieve the redshift (3)
62- 66 F5.2 mag z'mag MegaCam SDSS_z' band magnitude (AB)
68- 72 F5.2 mag Hmag ?=99. WIRCam H band magnitude (AB)
74 I1 --- Pf [0/1]? Photometric flag, 0=best (4)
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Note (1): Cluster member galaxies, ext#N A, ext#1 to ext#6 for the galaxy
clusters, A-Q for the galaxy members.
Note (2): Spectrocopic validity flag as follows:
0 = secure and precise redshift
1 = still stands for a good, science grade, but not optimal spectra
2 = doubt or ambiguity of the spectroscopic identification and hence
is to be used with care
Note (3): The passive and emission templates are taken from Kinney et al.,
1996ApJ...467...38K 1996ApJ...467...38K
Note (4): Photometric flag as follows:
0 = photometric data is good
1 = magnitudes might be affected by photometric effects
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Acknowledgements:
Arjen de Hoon, arjen(at)aip.de
History:
* 08-Feb-2013: On-line version
* 30-Sep-2013: In speclong.dat, for Source 34,
ext#3 Q corrected into ext#3 C, as in table6 of the paper
(End) Arjen de Hoon [AIP, Germany], Patricia Vannier [CDS] 12-Dec-2012