J/A+A/699/A257 Properties of giant radio galaxies >3 Mpc (Andernach+ 2025)
Properties of giant radio galaxies larger than 3 Mpc.
Andernach H., Brueggen M.
<Astron. Astrophys. 699, A257 (2025)>
=2025A&A...699A.257A 2025A&A...699A.257A (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; Radio sources ; Galaxies, radio
Keywords: galaxies: active - galaxies: jets
Abstract:
We examine the properties of giant radio galaxies GRGs with largest
linear sizes larger than 3 Mpc in order to shed light on the nature
and origin of GRGs. We select, corroborate, and revise or reject if
necessary, the largest GRGs from literature, and add to these 69 GRGs
we identified in our own search. We use recent optical surveys to find
their hosts, and catalogues of spectroscopic and photometric redshifts
in order to find their projected linear radio size. We present a
sample of 142 GRGs larger than 3Mpc, of which 69 were newly found by
us. The sample includes six GRGs with projected linear sizes clearly
exceeding 5Mpc and reaching up to 6.6Mpc. We study their radio
power-size relation, the asymmetry in the lobes, their association
with clusters of galaxies, as well as their bending angles.
We find that GRGs larger than 3 Mpc are distributed in redshift and
radio luminosity indistinguishable from those of smaller GRGs. Only 6
per cent deviate from a clear FR II radio morphology. One quarter of
our GRGs show very diffuse lobes typical for remnant radio galaxies,
and only 59 per cent show indications of hotspots in at least one
lobe, with 38 per cent featuring a hotspot in both lobes. As in the
case of smaller radio galaxies, the shorter lobe is most often also
the brighter one. We find tentative evidence that the bending angle
decreases with size of the GRG, but no trend with redshift is
detected. The fraction of hosts of GRGs larger than 3Mpc associated
with galaxy clusters is indistinguishable from that for smaller GRGs,
but the bending angles of GRGs>3Mpc in known clusters are larger than
for those GRGs not associated with clusters.
Description:
We report radio and optical parameters of 142 radio sources with
projected linear sizes larger than 3Mpc. Of these, 69 were newly
found by us from inspection of recent radio and optical/infrared
survey images. We determine their largest angular and linear sizes,
total flux densities and spectral luminosities at 145MHz, as well as
sizes and fluxes for each of their lobes, from which we derive an
armlength ratio defined here as the ratio of the length of the brigher
lobe by that of the fainter one. We also measure the bending angle of
the vectors from the host to the outermost radio emission peaks, as
well as the host's membership to galaxy clusters from the most
recently published cluster catalogues.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 135 142 Radio-optical data for 142 GRGs >3Mpc
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- JName GRG object designation, JHHMM+DDMM (1)
12 A1 --- Note [abcdefgh-] special note on the object (2)
14- 31 A18 --- RADECJ RA,DEC(J2000) of GRG host in sexagesimal
format Jhhmmss.ss+ddmmss.s
33- 40 F8.4 deg RAdeg Right ascension (J2000) of GRG host
42- 49 F8.4 deg DEdeg Declination (J2000) of GRG host
51- 56 F6.4 --- z Redshift adopted for the host (3)
58- 59 A2 --- ztype [spe* ] Type of redshift (4)
61- 62 A2 --- Class Type of host of the ERG (5)
64- 87 A24 --- HostName Name of the GRG optical host
89 A1 --- hflag [?-] ? if host is uncertain
91- 95 F5.2 arcmin LAS Largest projected angular size of ERG
97-100 F4.2 Mpc LLS Largest projected linear size (6)
102-105 F4.1 deg BA ? Bending angle between opposite lobes
108-111 F4.2 --- ALR ? Armlength ratio = length ratio of
brighter-to-fainter lobe
114-115 A2 --- survFL ? Survey used for flux integration (7)
117-123 F7.1 mJy Fsurv ? Total flux density at survey frequency
125-129 F5.2 [W/Hz] logP145 ? Decimal log of 145MHz spectral power (6)
extrapolating Fsurv to 145MHz with
a spectral index of alpha=-0.8
131-132 A2 --- proven Code for provenance (8)
134-135 A2 --- environm Cluster association flag (9)
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Note (1): the name JHHMM+DDMM is created from truncated J2000 host coordinates.
Note (2): Notes on individual objects as follows:
a = J0101+5052 and J0843-0208 may have alternative hosts at lower
redshift implying LLS values of 1.3 and 2.7 Mpc, respectively.
We consider the hosts quoted here as the more likely ones.
b = The host of this GRG was wrongly identified by Oei et al.
(2023A&A...672A.163O 2023A&A...672A.163O) as SDSS J013406.32+301537.2, but high-resolution
images at 1.4 and 5GHz by White et al. (2019ApJS..241...37W 2019ApJS..241...37W) show it
to be a restarted RG hosted by SDSS J013410.63+301537.7, also detected
as X-ray source 4XMM J013410.7+301538.
c = These 7 sources are from Oei et al. (2023A&A...672A.163O 2023A&A...672A.163O) but are not
in the public LoTSS DR2 footprint. For 3 of these we could not find
suitable other radio surveys to determine ALR, BA and P145.
For J0722+4242 we adopt a host, SDSS J072238.26+424227.2,
different from that in Oei et al. (2023A&A...672A.163O 2023A&A...672A.163O) since it
coincides with a 0.7-mJy VLASS radio core.
d = Listed as J0905+5527 in Oei et al. (2023A&A...672A.163O 2023A&A...672A.163O) who propose
SDSS J090528.26+552711.7 as the host, which is undetected
in both LoTSS and VLASS. We propose DESI J136.4012+55.4346 as
the host as it has a radio core in both LoTSS and VLASS and is
located closer to the GRG's major axis. Its higher redshift
implies a higher LLS.
e = Listed with z_spec=1.8857 in Debski et al. (2025ApJ...978..101D 2025ApJ...978..101D) but the
spectrum is very noisy and the redshift unreliable (M. Debski,
priv.comm.)
f = Oei et al. (2023A&A...672A.163O 2023A&A...672A.163O) propose SDSS J132002.53+602231.0 as the
host which lies off due SW of the GRG's major radio axis, is faint
in LoTSS and undetected in VLASS. We propose SDSS J132024.00+602235.2
as the host, as it lies closer to the major source axis and has
jet-like emission on both sides directed towards the outer lobes.
g = We agree with the host proposed by Hardcastle et al.
(2023A&A...678A.151H 2023A&A...678A.151H) but note that SDSS J160513.70+443347.8 may be
another candidate. Its WISE color, redshift, and thus LLS, would be
similar but its ALR of about 1.05 would make it statistically less
probable.
h = Hardcastle et al. (2023A&A...678A.151H 2023A&A...678A.151H) list a smaller LAS of 6.40 and
propose SDSS J163749.12+395038.3 with a strong compact radio source as
the host. The DESI Legacy Survey DR10 resolves the SDSS object into a
close pair of galaxies about 1.5 arcsec apart, and VLASS shows the
fainter SW component to be the host of the radio source.
Since this source is located off the GRG's major radio axis we prefer
SDSS J163753.66+394916.0 as the host which is closer to the symmetry
centre of the GRG and has more AGN-like WISE colors.
The redshift and LLS are similar for both hosts.
Note (3): Spectroscopic redshifts were taken from:
Hill et al., 1996ApJ...462..163H 1996ApJ...462..163H
Colless et al., 2001MNRAS.328.1039C 2001MNRAS.328.1039C (Cat. VII/226/)
Miller et al., 2001ApJS..134..355M 2001ApJS..134..355M (Cat. J/ApJS/134/355/)
Saripalli et al., 2005AJ....130..896S 2005AJ....130..896S (Cat. J/AJ/130/896/)
Machalski et al., 2008ApJ...679..149M 2008ApJ...679..149M
Huchra et al., 2012ApJS..199...26H 2012ApJS..199...26H (Cat. J/ApJS/199/26/)
O'Sullivan et al., 2019A&A...622A..16O 2019A&A...622A..16O
Oei et al., 2024Natur.633..537O 2024Natur.633..537O
DESI Collaboration, 2025, (DESI DR1, arXiv:2503.14745)
Luo et al., 2019, (LAMOST DR7, Cat. V/156)
Ahumada et al., 2020ApJS..249....3A 2020ApJS..249....3A (SDSS DR16)
and photometric redshifts were taken from the following references,
and an average value adopted when multiple values were found for
the same object:
Ahumada et al., 2020ApJS..249....3A 2020ApJS..249....3A (SDSS DR16,
based on Beck et al., 2016MNRAS.460.1371B 2016MNRAS.460.1371B, Cat. V/154)
Brescia et al., 2014A&A...568A.126B 2014A&A...568A.126B (SDSS-DR9)
Beck et al., 2021MNRAS.500.1633B 2021MNRAS.500.1633B (Pan-STARRS)
Beck et al., 2022MNRAS.515.4711B 2022MNRAS.515.4711B (Pan-STARRS)
Bilicki et al., 2014ApJS..210....9B 2014ApJS..210....9B (2MASX)
Bilicki et al., 2016ApJS..225....5B 2016ApJS..225....5B (AllWISE)
Duncan et al., 2022MNRAS.512.3662D 2022MNRAS.512.3662D (DESI-DR8, Cat. VII/292)
Duncan et al., 2021A&A...648A...4D 2021A&A...648A...4D (LoTSS Deep Fields, Cat. J/A+A/648/A4)
Flesch 2015, 2015PASA...32...10F 2015PASA...32...10F (Cat. VII/273/)
Shu et al., 2019MNRAS.489.4741S 2019MNRAS.489.4741S
Zou et al., 2022RAA....22f5001Z 2022RAA....22f5001Z (DESI DR9)
Yang et al., 2021ApJ...909..143Y 2021ApJ...909..143Y
Zhou et al., 2021MNRAS.501.3309Z 2021MNRAS.501.3309Z (DESI-DR9)
Zhou et al., 2025MNRAS.536.2260Z 2025MNRAS.536.2260Z (DESI-LS with DESI EDR)
Wen & Han 2024, 2024ApJS..272...39W 2024ApJS..272...39W (DESI DR10, Cat. J/ApJS/272/39/)
Note (5): Type of host of the ERG as follows:
G = galaxy
GP = galaxy pair
Q = quasar
QB = quasar with broad emission lines
Qc = quasar candidate
with a ? is appended if the class is uncertain
Note (4): Type of redshift as follows:
s = spectroscopic
p = photometric
e = estimated by us
s* = unpubl. spectroscopic redshift obtained by us at GTC in 2015
Note (6): based on H0=70km/s/Mpc, Omegam=0.3, OmegaLambda=0.7
Note (7): radio survey images used for the flux integration were as follows:
A = ASKAP at 944 MHz (Norris et al., 2021PASA...38...48N 2021PASA...38...48N) or
SWAG-X (V. Moss, priv. comm) at 888 MHz;
L = LOFAR at 145 MHz (Shimwell et al., 2022A&A...659A...1S 2022A&A...659A...1S;
Edler et al. 2023PASA...40...34D 2023PASA...40...34D)
MA = MALS DR2 (Wagenveld et al. 2024, arXiv e-prints [arXiv:1808.07178])
at 1.27 GHz;
N = NVSS at 1.4 GHz (Condon et al., 1998AJ....115.1693C 1998AJ....115.1693C);
R = RACS (McConnell et al. 2020PASA...37...48M 2020PASA...37...48M;
Duchesne et al. 2023PASA... 40...34D) at 888 and 1367 MHz;
T = TGSS at 150 MHz (Intema et al.. 2017A&A...598A..78I 2017A&A...598A..78I),
Note (8): The provenance of the object is coded as follows:
A = ASKAP-EMU (Evolutionary Map of the Universe, Hopkins et al.
(2025, ArXiv e-prints [arXiv:2505.08271] ) or other ASKAP project,
ED = LOFAR Euclid Deep Field North (Bondi et al., 2024A&A...683A.179B 2024A&A...683A.179B),
MA = MeerKAT MALS DR2 (Wagenveld et al., 2024A&A...690A.163W 2024A&A...690A.163W) at 1.27MHz,
MW = MWA: EoR images (Offringa et al., 2016MNRAS.458.1057O 2016MNRAS.458.1057O;
Lynch et al. 2021PASA...38...57L 2021PASA...38...57L),
GLEAM (Hurley-Walker et al., 2017MNRAS.464.1146H 2017MNRAS.464.1146H) or
GLEAM-X DR1 (Hurley-Walker et al., 2022PASA...39...35H 2022PASA...39...35H)
N = new discovery by us, mostly from NVSS or LoTSS, or otherwise found by
us in
P = from published literature, mainly in Kuzmicz et al.
(2018ApJS..238....9K 2018ApJS..238....9K); Andernach et al. (2021Galax...9...99A 2021Galax...9...99A);
Oei et al. (2023A&A...672A.163O 2023A&A...672A.163O); Hardcastle et al.
(2023A&A...678A.151H 2023A&A...678A.151H); Simonte et al. (2024A&A...686A..21S 2024A&A...686A..21S);
Mostert et al. (2024A&A...691A.185M 2024A&A...691A.185M), Koribalski (2025ARep...53.1086K 2025ARep...53.1086K)
R = Radio Galaxy Zoo (Banfield et al., 2015MNRAS.453.2326B 2015MNRAS.453.2326B;
Wong et al., 2025MNRAS.536.3488W 2025MNRAS.536.3488W)
V = LOFAR image (VICTORIA project: Edler et al., 2023A&A...676A..24E 2023A&A...676A..24E)
n = literature, but not listed there as GRG
Note (9): The host galaxy is listed as b = brightest cluster galaxy,
m = cluster member galaxy or i = isolated galaxy,
in one or more of the following galaxy cluster catalogues:
Hao et al., 2010ApJS..191..254H 2010ApJS..191..254H; Szabo et al., 2011ApJ...736...21S 2011ApJ...736...21S;
Wen & Han, 2015ApJ...807..178W 2015ApJ...807..178W, Zou et al., 2022RAA....22f5001Z 2022RAA....22f5001Z,
Yang et al., 2021ApJ...909..143Y 2021ApJ...909..143Y; Zou et al., 2021ApJS..253...56Z 2021ApJS..253...56Z,
Yantovski-Barth et al., 2024MNRAS.531.2285Y 2024MNRAS.531.2285Y;
Zou et al. 2022RAA....22f5001Z 2022RAA....22f5001Z, (Wen & Han, 2024ApJS..272...39W 2024ApJS..272...39W,
Oguri et al., 2018PASJ...70S..20O 2018PASJ...70S..20O; Zou et al. 2022RAA....22f5001Z 2022RAA....22f5001Z.
Note that the presence of more than one code for the same object
is likely due to inconsistencies between different galaxy cluster
catalogues based on different cluster finding algorithms.
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Acknowledgements:
Heinz Andernach, heinz(at)ugto.mx
(End) Heinz Andernach [Univ. Guanajuato], Patricia Vannier [CDS] 15-Jul-2025