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J/ApJ/844/78  The high-redshift COBRA survey: IRAC obs.  (Paterno-Mahler+, 2017)

The high-redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: the Spitzer catalog. Paterno-Mahler R., Blanton E.L., Brodwin M., Ashby M.L.N., Golden-Marx E., Decker B., Wing J.D., Anand G. <Astrophys. J., 844, 78 (2017)> =2017ApJ...844...78P
ADC_Keywords: Clusters, galaxy ; Photometry, infrared ; Redshifts ; Radio continuum ; QSOs Keywords: galaxies: clusters: general; galaxies: evolution; galaxies: high-redshift; infrared: galaxies; radio continuum: galaxies Abstract: We present 190 galaxy cluster candidates (most at high redshift) based on galaxy overdensity measurements in the Spitzer/IRAC imaging of the fields surrounding 646 bent, double-lobed radio sources drawn from the Clusters Occupied by Bent Radio AGN (COBRA) Survey. The COBRA sources were chosen as objects in the Very Large Array FIRST survey that lack optical counterparts in the Sloan Digital Sky Survey to a limit of mr=22, making them likely to lie at high redshift. This is confirmed by our observations: the redshift distribution of COBRA sources with estimated redshifts peaks near z=1 and extends out to z∼3. Cluster candidates were identified by comparing our target fields to a background field and searching for statistically significant (≥2σ) excesses in the galaxy number counts surrounding the radio sources; 190 fields satisfy the ≥2σ limit. We find that 530 fields (82.0%) have a net positive excess of galaxies surrounding the radio source. Many of the fields with positive excesses but below the 2σ cutoff are likely to be galaxy groups. Forty-one COBRA sources are quasars with known spectroscopic redshifts, which may be tracers of some of the most distant clusters known. Description: The Spitzer Infrared Array Camera (IRAC) observations of the Clusters Occupied by Bent Radio AGN (COBRA) sources were carried out as a Snapshot Program during Cycle 8 (PID 80161, PI Blanton). All 646 sources were imaged at 3.6um. We also observed 135 sources at 4.5um. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 108 646 COBRA cluster survey catalog
See also: VII/4 : Abell and Zwicky Clusters of Galaxies (Abell+ 1974) II/294 : SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009) VIII/92 : The FIRST Survey Catalog, Version 2014Dec17 (Helfand+ 2015) J/A+A/461/823 : Candidate Lyα emitting galaxies (Venemans+, 2007) J/ApJ/684/905 : z>1 gal. clusters from IRAC Shallow Survey (Eisenhardt+, 2008) J/ApJ/686/966 : Spitzer-FLS catalog of clusters of galaxies (Muzzin+, 2008) J/AJ/141/88 : Galaxy cluster environments of radio sources (Wing+, 2011) J/ApJ/769/79 : Spitzer obs. of radio-loud AGNs (CARLA) (Wylezalek+, 2013) J/ApJS/213/25 : WISE Massive & Distant Clusters (MaDCoWS) II. (Stanford+, 2014) J/ApJ/786/17 : Luminosity functions for 1.3<z<3.2 galaxies (Wylezalek+, 2014) J/ApJS/218/33 : Spitzer-CANDELS catalog within 5 deep fields (Ashby+, 2015) J/ApJS/216/27 : Galaxy clusters discovered in the SPT-SZ survey (Bleem+, 2015) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1 I1 --- Type [1/3] Source selection type (1) 3- 7 A5 --- --- [COBRA] 8- 22 A15 --- COBRA Radio source name (HHMMSS.s+DDMMSS; J2000) 24- 25 I2 h RAh ? Hour of Right Ascension (J2000) (2) 27- 28 I2 min RAm ? Minute of Right Ascension (J2000) (2) 30- 34 F5.2 s RAs ? Second of Right Ascension (J2000) (2) 36 A1 --- DE- Sign of the Declination (J2000) (2) 37- 38 I2 deg DEd ? Degree of Declination (J2000) (2) 40- 41 I2 arcmin DEm ? Arcminute of Declination (J2000) (2) 43- 46 F4.1 arcsec DEs ? Arcsecond of Declination (J2000) (2) 48- 53 F6.1 mJy S20 [2/1503] FIRST survey 20cm flux density 55- 59 F5.2 mag 3.6mag [12.7/23.8]? Host Spitzer/IRAC 3.6um band mag as determined by SExtractor. 61- 65 F5.2 mag 3.6-4.5 [-0.6/0.7]? Host Spitzer/IRAC 3.6-4.5um band color index 67 A1 --- f_3.6-4.5 Flag on 3.6-4.5 (3) 69- 73 F5.3 --- z [0/3]? Redshift (4) 75 A1 --- f_z Flag on z (5) 77- 81 F5.1 --- DelN1 [-14/50] Overdensity within 1 arcmin 83- 85 F3.1 --- e_DelN1 [3/9] Uncertainty in DelN1 (6) 87- 91 F5.2 --- Sig1 [-2.2/7.8] Significance within 1 arcmin (7) 93- 97 F5.1 --- DelN2 [-45/120] Overdensity within 2 arcmin 99-102 F4.1 --- e_DelN2 [8/16] Uncertainty in DelN2 (6) 104-108 F5.2 --- Sig2 [-3.1/8.1] Significance within 2 arcmin (7)
Note (1): Source type as follows: 1 = 3.6 micron band only; 2 = 3.6 and 4.5 micron (103 occurrences); 3 = Quasars (40 occurrences). Note (2): Of the optical/IR host, which in some cases differs from that of the radio source (see text). A blank indicates that no host could be identified. Note (3): Flag as follows: g = The listed coordinates of the radio source are not those of the identified host. The identified host of the radio source was not at the center of the search radius used to calculate an overdensity. h = Color could not be determined due to nearby saturated pixels. i = Object identified as host is identified as a star in SDSS. Note (4): Photometric redshift available in SDSS, unless otherwise noted. Quasar redshifts are spectroscopically determined. Note (5): Flag as follows: c = Spectroscopic redshift from SDSS (69 occurrences). d = Redshift is derived from the color of the source associated with the radio contours (35 occurrences). See text for more details. e = While the listed color is too red to determine a redshift based on our models, examining the surrounding sources yields the listed redshift. f = Identified in the SDSS Digital Release 6 Galaxy Clusters Catalog. j = Spectroscopically determined redshift from Blanton+ (2003AJ....125.1635B). Redshift from the color is 0.99. k = Source observed at 3.6 micron only later identified as a quasar. Note (6): Including Poisson noise contributions from both the cluster and background subtraction. Note (7): Computed using Equation 2 (Significance=ΔN/σSpUDS), which relates the overdensity to the standard deviation of the Spitzer UKIDSS Ultra Deep Survey (SpUDS, PI: J. Dunlop) field in each aperture size.
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDs] 05-Mar-2018
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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