J/ApJ/907/65 COBRA Radio source properties (Golden-Marx+, 2021)
The High-redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: Radio
Source Properties.
Golden-Marx E., Blanton E.L., Paterno-Mahler R., Brodwin M., Ashby M.L.N.,
Moravec E., Shen L., Lemaux B.C., Lubin L.M., Gal R.R., Tomczak A.R.
<Astrophys. J., 907, 65 (2021)>
=2021ApJ...907...65G 2021ApJ...907...65G
ADC_Keywords: Clusters, galaxy; Radio sources; Infrared; Redshifts
Keywords: High-redshift galaxy clusters ; Galaxy clusters ; Extragalactic
radio sources ; Fanaroff-Riley radio galaxies ; Galaxy
evolution ; Infrared galaxies ; Radio galaxies ; Tailed radio
galaxies
Abstract:
The shape of bent, double-lobed radio sources requires a dense gaseous
medium. Bent sources can therefore be used to identify galaxy clusters
and characterize their evolutionary history. By combining radio
observations from the Very Large Array Faint Images of the Radio Sky
at Twenty centimeters (VLA FIRST) survey with optical and infrared
imaging of 36 red sequence selected cluster candidates from the high-z
Clusters Occupied by Bent Radio AGN (COBRA) survey (0.35<z<2.2), we
find that radio sources with narrower opening angles reside in richer
clusters, indicating that the cluster environment impacts radio
morphology. Within these clusters, we determine 55.5% of our radio
host galaxies are brightest cluster galaxies (BCGs) and that the
remainder are associated with other luminous galaxies. The projected
separations between the radio sources and cluster centers and the
sizes of the opening angles of bent sources follow similar
distributions for BCG and non-BCG host populations, suggesting that
COBRA host galaxies are either BCGs or galaxies that may evolve into
BCGs. By measuring the orientation of the radio sources relative to
the cluster centers, we find between 30% and 42% of COBRA bent sources
are outgoing and have passed through the cluster center, while between
8% and 58% of COBRA bent sources are infalling. Although these sources
typically do not follow directly radial paths, the large population of
outgoing sources contrasts what is observed in low-z samples of bent
sources and may indicate that the intracluster medium is less dense in
these high-z clusters.
Description:
The high-z COBRA survey consists of 646 bent, double-lobed radio
sources. Each source in the high-z COBRA survey was observed as part
of a Spitzer Snapshot program (PI: Blanton) in IRAC 3.6µm and 135
were observed in 4.5µm.
The optical follow-up consists of observations taken on the 4.3m
Lowell Discovery Telescope11 (LDT) at Lowell Observatory using the
Large Monolithic Imager (LMI). The LMI has a 12.3'x12.3' field of
view, as compared to the ∼5'x5' FOV on Spitzer IRAC, allowing us to
observe both the cluster and the surrounding field. Observations
consist of 90 fields in i-band and 38 in r-band for either 3x600s or
3x900s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 101 38 COBRA red sequence clusters and radio source
properties
table2.dat 94 36 COBRA radio source properties
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See also:
J/ApJS/169/225 : Photometry of galaxies in the Coma cluster (Eisenhardt+, 2007)
J/AJ/141/88 : Galaxy cluster environments of radio sources (Wing+, 2011)
J/ApJS/199/34 : Clusters of galaxies in SDSS-III (Wen+, 2012)
J/MNRAS/430/3086 : CoNFIG AGN sample (Gendre+, 2013)
J/ApJ/769/79 : Spitzer observations radio-loud AGNs (CARLA) (Wylezalek+, 2013)
J/A+A/572/A41 : VUDS Dicovery of a high-redshift protocluster (Lemaux+, 2014)
J/ApJ/785/104 : redMaPPer. I. Algorithm applied to SDSS DR8 (Rykoff+, 2014)
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/ApJ/807/178 : Newly rich galaxy clusters identified in SDSS-DR12 (Wen+, 2015)
J/ApJ/816/98 : Galaxies Xray clusters with DES. I. Stellar mass (Zhang+, 2016)
J/ApJ/844/78 : High-redshift COBRA survey; IRAC obs. (Paterno-Mahler+, 2017)
J/ApJ/859/38 : HST grism obs. CARLA galaxy cluster candidates (Noirot+, 2018)
J/AJ/157/126 : RGZ distortion radio galaxies by galaxy clusters (Garon+, 2019)
J/ApJS/240/33 : MaDCoWS. I. Catalog of z∼1 galaxy clusters (Gonzalez+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Type Type of source (1)
3- 22 A20 --- COBRA COBRA identifier
24 A1 --- f_COBRA Flag on identifier (2)
26- 30 F5.3 --- z [0.35/2.18] Redshift
32- 33 I2 h RAh [0/22] Hour of right ascension (J2000)
35- 36 I2 min RAm Minute of right ascension (J2000)
38- 42 F5.2 s RAs Second of right ascension (J2000)
44 A1 --- DE- [±] Sign of declination (J2000)
46- 47 I2 deg DEd Degree of declination (J2000)
49- 50 I2 arcmin DEm Arcminute of declination (J2000)
52- 55 F4.1 arcsec DEs Arcsecond of declination (J2000)
57- 58 I2 h RACh [0/22] RS Cluster Hour of right ascension (J2000)
60- 61 I2 min RACm RS Cluster Minute of right ascension (J2000)
63- 67 F5.2 s RACs RS Cluster Second of right ascension (J2000)
69 A1 --- DEC- RS Cluster Sign of declination (J2000)
71- 72 I2 deg DECd RS Cluster Degree of declination (J2000)
74- 75 I2 arcmin DECm RS Cluster Arcminute of declination (J2000)
77- 80 F4.1 arcsec DECs RS Cluster Arcsecond of declination (J2000)
82- 87 F6.1 kpc AGN [-593/1216]? AGN offset
89- 93 F5.1 deg Inf [0.8/146]? Infall angle
95- 97 F3.1 --- RS [1/9.6] Overdensity signifiance RS
99-101 F3.1 --- Comb [0.8/6.7] Overdensity signifiance combined
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Note (1): Types as follows:
A = m*+1i-[3.6] cluster candidates
B = m*+1r-i cluster candidates
C = magnitude-limited i-[3.6] cluster candidates
D = magnitude-limited [3.6]-[4.5] cluster candidates
Note (2): Flag as follows:
b = Cluster candidates without evidence of a bent radio AGN and for
which we do not report any measurements relating to the AGN.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- Type Type of source (1)
3- 22 A20 --- COBRA Identifier of the source
24 A1 --- f_COBRA Flag on identifier (2)
26- 31 F6.2 deg Ang [36/161] Opening angle
33- 35 F3.1 deg e_Ang [0/7] Error on Ang
37- 41 F5.1 kpc Length [123/595] Radio source length
43- 47 F5.1 kpc e_Length [-22/-1] Negative error on Length
49- 53 F5.1 kpc E_Length [2/18] Positive error on Lenght
55- 60 F6.2 mJy Flux [3.87/286] Radio Flux
62- 67 F6.2 W/Hz P1.44 [0.5/363] Radio power (1025W/Hz)
69- 74 F6.2 W/Hz e_P1.44 [-40/-0] Negative error on P1.44
76- 81 F6.2 W/Hz E_P1.44 [0/40.53] Positive error on P1.44
83- 87 F5.2 mag 3.6mag [16.5/23.1]? 3.6µm magnitude
89- 94 F6.2 mag 3.6MAG [-25.3/-18.4]? 3.6µm absolute magnitude
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Note (1): Types as follows:
A = m*+1i-[3.6] cluster candidates
B = m*+1r-i cluster candidates
C = magnitude-limited i-[3.6] cluster candidates
D = magnitude-limited [3.6]-[4.5] cluster candidates
Note (2): Flags as follows:
a = Radio sources that are SDSS quasars
b = Sources that lack a third radio component
c = Sources where one of the radio components was not convolved
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History:
From electronic version of the journal
(End) Prepared by Coralie Fix [CDS], 10-Jun-2022