J/AJ/157/126 RGZ: distortion of radio galaxies by galaxy clusters (Garon+, 2019)
Radio Galaxy Zoo: the distortion of radio galaxies by galaxy clusters.
Garon A.F., Rudnick L., Wong O.I., Jones T.W., Kim J.-A., Andernach H.,
Shabala S.S., Kapinska A.D., Norris R.P., de Gasperin F., Tate J., Tang H.
<Astron. J., 157, 126 (2019)>
=2019AJ....157..126G 2019AJ....157..126G (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, radio ; Redshifts ; Morphology
Keywords: galaxies: clusters: intracluster medium - radio continuum: galaxies
Abstract:
We study the impact of cluster environment on the morphology of a sample
of 4304 extended radio galaxies from Radio Galaxy Zoo. A total of 87%
of the sample lies within a projected 15 Mpc of an optically identified
cluster. Brightest cluster galaxies (BCGs) are more likely than other
cluster members to be radio sources, and are also moderately bent. The
surface density as a function of separation from cluster center of non-BCG
radio galaxies follows a power law with index -1.10±0.03 out to 10 r500
(∼7 Mpc), which is steeper than the corresponding distribution for
optically selected galaxies. Non-BCG radio galaxies are statistically more
bent the closer they are to the cluster center. Within the inner 1.5 r500
(∼1 Mpc) of a cluster, non-BCG radio galaxies are statistically more bent
in high-mass clusters than in low-mass clusters. Together, we find that
non-BCG sources are statistically more bent in environments that exert
greater ram pressure. We use the orientation of bent radio galaxies as
an indicator of galaxy orbits and find that they are preferentially in
radial orbits. Away from clusters, there is a large population of bent
radio galaxies, limiting their use as cluster locators; however, they are
still located within statistically overdense regions. We investigate
the asymmetry in the tail length of sources that have their tails aligned
along the radius vector from the cluster center, and find that the length
of the inward-pointing tail is weakly suppressed for sources close to
the center of the cluster.
Description:
The Radio Galaxy Zoo (RGZ) catalog comprises radio sources that citizen
scientists have matched to infrared host galaxies. The main value of RGZ
comes from the matching of associated and possibly disconnected radio
source components, as well as the cross-identification of host galaxies.
The bulk of the radio data in the RGZ catalog comes from the Faint Images
of the Radio Sky at Twenty Centimeters survey (FIRST; Becker et al.
1995ApJ...450..559B 1995ApJ...450..559B; White et al. 1997, Cat. VIII/59), and we combine
radio galaxy classifications generated by the citizen scientists with
additional data derived from the radio contours from FIRST, which begin
at a level four times the local noise. For this paper, sources with IR
counterparts were cross-matched to the Sloan Digital Sky Survey DR13
catalog (SDSS; Albareti et al. 2017ApJS..233...25A 2017ApJS..233...25A), providing redshift
measurements and improved angular resolution over WISE. We present two
supplementary data tables: one consisting of the 3723 sources matched
to Wen & Han (2015, J/ApJ/807/178, hereafter WH15) within a projected
separation of 15 Mpc and redshift difference of ±0.04(1+z), and the
other consisting of the 581 sources not matched to WH15.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2a.dat 171 3723 The matched data sample used in this work
table2b.dat 94 581 The unmatched data sample used in this work
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See also:
VIII/59 : the FIRST Survey, version 1999Jul (White+ 1999)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
VIII/92 : The FIRST Survey Catalog, Version 2014Dec17 (Helfand+ 2015)
J/AJ/141/88 : Galaxy cluster environments of radio sources (Wing+, 2011)
J/ApJ/807/178 : Newly rich galaxy clusters identified in SDSS-DR12 (Wen+, 2015)
http://radio.galaxyzoo.org/ : Radio Galaxy Zoo website
Byte-by-byte Description of file: table2a.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Name Radio Galaxy Zoo source name
(JHHMMSS.s+DDMMSS)
18- 27 A10 --- ZID Zooniverse subject name
29 I1 --- Morph [2/3] Radio morphology (G1)
31- 35 F5.3 arcmin LAS [0.165/1.499] Largest angular size
37- 45 F9.5 deg RAdeg SDSS host galaxy Right Ascension (J2000)
47- 54 F8.5 deg DEdeg SDSS host galaxy Declination (J2000)
56- 61 F6.4 --- z [0.0236/0.7959] SDSS host galaxy redshift
63- 68 F6.4 --- e_z [0/0.6674] SDSS redshift error
70 A1 --- f_z [ps] SDSS redshift type (G2)
72- 76 F5.1 deg BA [0/179.8] Bending angle θ
78- 82 F5.1 deg CBA [0/132.8] Corrected bending angle
θcorr
84- 88 F5.1 deg EBA [-7.3/132.6] Excess bending angle
Δθ
90- 94 F5.2 --- Asym [0.01/17.61] Source asymmetry (G3)
96-111 A16 --- WH15 Cluster name from Wen & Han (2015,
J/ApJ/807/178, hereafter WH15)
(JHHMMSS.s+DDMMSS)
113-121 F9.5 deg RAWHdeg WH15 cluster Right Ascension (J2000)
123-130 F8.5 deg DEWHdeg WH15 cluster Declination (J2000)
132-137 F6.4 --- z-WH [0.045/0.7492] WH15 cluster redshift
139 A1 --- f_z-WH [ps] WH15 redshift type (G2)
141-145 F5.2 --- Sep [0/38.17] Separation from the nearest WH15
cluster (in units of r500)
147-150 F4.2 Mpc r500 [0.22/1.44] WH15 radius of the nearest WH15
cluster
152-156 F5.2 10+14Msun M500 [0.35/76.98] WH15 mass of the nearest WH15
cluster
158-163 F6.2 [keV/cm3] logPicm [-10.99/0.65] log10 of the local ICM gas
pressure
165-169 F5.1 deg Phi [0.1/180] Opening angle orientation Φ
171 A1 --- Ali [ort] Tail alignment (1)
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Note (1): Alignment of the source tails with respect to the cluster as follows:
r = Radial;
t = Tangential;
o = Other.
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Byte-by-byte Description of file: table2b.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Radio Galaxy Zoo source name (JHHMMSS.s+DDMMSS)
18- 27 A10 --- ZID Zooniverse subject name
29 I1 --- Morph [2/3] Radio morphology (G1)
31- 35 F5.3 arcmin LAS [0.164/1.451] Largest angular size
37- 45 F9.5 deg RAdeg SDSS host galaxy Right Ascension (J2000)
47- 54 F8.5 deg DEdeg SDSS host galaxy Declination (J2000)
56- 61 F6.4 --- z [0.0466/0.7995] SDSS host galaxy redshift
63- 68 F6.4 --- e_z [0/0.2578] SDSS redshift error
70 A1 --- f_z [ps] SDSS redshift type (G2)
72- 76 F5.1 deg BA [0/174.5] Bending angle θ
78- 82 F5.1 deg CBA [0/132.9] Corrected bending angle θcorr
84- 88 F5.1 deg EBA [-7.3/132.3] Excess bending angle Δθ
90- 94 F5.2 --- Asym [0.06/19.73] Source asymmetry (G3)
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Global notes:
Note (G1): Radio morphology as follows:
2 = Double;
3 = Triple.
Note (G2): Type of redshift as follows:
s = Spectroscopic;
p = Photometric.
Note (G3): Defined as the ratio of the lengths of the inward-pointing tail to
the outward-pointing tail. For sources not matched to clusters, a tail was
randomly selected as the "inward-pointing" one. See Section 5.7 for more
information.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 14-Jun-2019