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J/A+A/607/A56     Distant clusters of galaxies in the 2XMM/SDSS  (Rabitz+, 2017)

Distant clusters of galaxies in the 2XMM/SDSS footprint: follow-up observations with the LBT. Rabitz A., Lamer G., Schwope A., Takey A. <Astron. Astrophys. 607, A56 (2017)> =2017A&A...607A..56R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources ; Photometry, SDSS Keywords: galaxies: clusters: general - galaxies: clusters: intracluster medium - X-rays: galaxies: clusters - cosmology: observations Abstract: Galaxy clusters at high redshift are important to test cosmological models and models for the growth of structure. They are difficult to find in wide-angle optical surveys, however, leaving dedicated follow-up of X-ray selected candidates as one promising identification route. We aim to increase the number of galaxy clusters beyond the SDSS-limit, z∼0.75. We compiled a list of extended X-ray sources from the 2XMMp catalogue within the footprint of the Sloan Digital Sky Survey. Fields without optical counterpart were selected for further investigation. Deep optical imaging and follow-up spectroscopy were obtained with the Large Binocular Telescope, Arizona (LBT), of those candidates not known to the literature. From initially 19 candidates, selected by visually screening X-ray images of 478 XMM-Newton observations and the corresponding SDSS images, 6 clusters were found in the literature. Imaging data through r,z filters were obtained for the remaining candidates, and 7 were chosen for multi-object (MOS) spectroscopy. Spectroscopic redshifts, optical magnitudes, and X-ray parameters (flux, temperature, and luminosity) are presented for the clusters with spectroscopic redshifts. The distant clusters studied here constitute one additional redshift bin for studies of the L-T relation, which does not seem to evolve from high to low redshifts. The selection method of distant galaxy clusters presented here was highly successful. It is based solely on archival optical (SDSS) and X-ray (XMM-Newton) data. Out of 19 selected candidates, 6 of the 7 candidates selected for spectroscopic follow-up were verified as distant clusters, a further candidate is most likely a group of galaxies at z∼1.21. Out of the remaining 12 candidates, 6 were known previously as galaxy clusters, one object is a likely X-ray emission from an AGN radio jet, and for 5 we see no clear evidence for them to be high-redshift galaxy clusters. Description: Positions and redshifts of the fields with spectroscopic follow-up with the LBT. The astrometry is based on the SDSS. We give redshifts based on LBT/MODS observations. Optical magnitudes were measured using SExtractor's ISO-mag on LBT/LBC imaging in the SLOAN-r and SLOAN-z filters. The errors for the magnitudes are given in extra columns, the redshift is printed out to the last two significant digits (except for stars). A flag indicates the affiliation and/or the astronomical classification of the object. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 65 193 Photometric and spectroscopic properties of sources with LBT follow-up
See also: J/MNRAS/366/171 : Red AGN in XMM/SDSS fields (Georgakakis+, 2006) J/ApJS/183/17 : The SDSS DR5/XMM-Newton quasar survey (Young+, 2009) J/MNRAS/457/110 : Northern XMM-XXL field AGN catalog (Menzel+, 2016) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh Right Ascension (J2000.0) 4- 5 I2 min RAm Right Ascension (J2000.0) 7- 8 I2 s RAs Right Ascension (J2000.0) 10 A1 --- DE- Declination sign (J2000.0) 11- 12 I2 deg DEd Declination (J2000.0) 14- 15 I2 arcmin DEm Declination (J2000.0) 17- 18 I2 arcsec DEs Declination (J2000.0) 20- 27 F8.6 --- z Redshift 29- 33 F5.1 arcsec Dist Distance to the X-ray center 35- 41 F7.4 mag rmag SLOAN r ISO magnitude 43- 48 F6.4 mag e_rmag Error in the r-SLOAN ISO magnitude 50- 56 F7.4 mag zmag SLOAN z ISO magnitude 58- 63 F6.4 mag e_zmag Error in the z-SLOAN ISO magnitude 65 I1 --- Flag [0/5]? Object type (1)
Note (1): Object type as follows: 0 = star 1 = bcg 2 = cluster member 3 = group member 4 = galaxy 5 = quasar
Acknowledgements: Andreas Rabitz, arabitz(at), Leibniz-Institut fur Astrophysik Potsdam
(End) Andreas Rabitz [Potsdam], Patricia Vannier [CDS] 25-Jul-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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