J/ApJ/926/65 Compilation of double radio sources (Xu+, 2022)
Evidence for strong intracluster magnetic fields in the early universe.
Xu J., Han J.L.
<Astrophys. J., 926, 65 (2022)>
=2022ApJ...926...65X 2022ApJ...926...65X
ADC_Keywords: Radio sources; Intergalactic medium; Magnetic fields; Redshifts
Keywords: Extragalactic magnetic fields ; Intracluster medium
Abstract:
The origin of magnetic fields in clusters of galaxies is still a
matter of debate. Observations for intracluster magnetic fields over a
wide range of redshifts are crucial to constrain possible scenarios
for the origin and evolution of the fields. Differences in Faraday
rotation measures (RMs) of an embedded double radio source, i.e., a
pair of lobes of mostly Fanaroff-Riley type II radio galaxies, are
free from the Faraday rotation contributions from the interstellar
medium inside the Milky Way and the intergalactic medium between radio
galaxies and us, and hence provide a novel way to estimate average
magnetic field within galaxy clusters. We have obtained a sample of
627 pairs whose RMs and redshifts are available in the most updated RM
catalogs and redshift databases. The RM differences of the pairs are
derived. The statistically large RM differences for pairs of redshifts
z>0.9 indicate that intracluster magnetic fields are as strong as
about 4µG. Such strong magnetic fields in the intracluster medium
at the half age of the universe, comparable to the intracluster field
strength in nearby galaxy clusters, pose a challenge to the theories
of the origin of cosmic magnetic fields.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 110 226 226 double radio sources with RM and redshift
data from the compiled data
(Xu & Han 2014, J/other/RAA/14.942 and afterward)
tablea2.dat 107 401 401 double radio sources with RM and redshift
data from the NVSS data (Taylor+ 2009, J/ApJ/702/1230)
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See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
V/154 : Sloan Digital Sky Surveys (SDSS) DR16 (Ahumada+, 2020)
J/MNRAS/381/341 : MRCR-SUMSS Ultra-steep-sp. (USS) sample (Broderick+, 2007)
J/ApJ/702/1230 : Rotation measure image of the sky (Taylor+, 2009)
J/ApJ/714/1170 : Faraday rotation at high Galactic latitude (Mao+, 2010)
J/ApJ/795/63 : Faraday rot. from magnesium II absorbers (Farnes+, 2014)
J/other/RAA/14.942 : Rotation measures of radio point sources (Xu+, 2014)
J/MNRAS/442/3329 : Rotation measures of 2642 quasars (Xu+, 2014)
J/ApJ/829/5 : S-PASS & NVSS extragalactic radio sources (Lamee+, 2016)
J/MNRAS/469/4034 : Broadband polarisation of radio AGN (O'Sullivan+, 2017)
J/ApJ/878/92 : Rotation measures in radio source pairs (Vernstrom+, 2019)
J/ApJ/890/132 : MgII abs. toward SDSS QSOs with rot. data (Malik+, 2020)
J/MNRAS/495/2607 : IGMF limits with LOFAR (O'Sullivan+, 2020)
J/other/PASA/37.29 : POGS-II ExGal catalog (Riseley+, 2020)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 deg RAdeg Source 1 Right Ascension (J2000)
10- 17 F8.4 deg DEdeg [-56.7/80] Source 1 Declination (J2000)
19- 26 F8.3 rad/m2 RM1 [-349.2/298] Source 1 rotation measure
28- 33 F6.3 rad/m2 e_RM1 [0.002/36.4] Uncertainty in RM1
35- 42 F8.4 deg RA2deg Source 2 Right Ascension (J2000)
44- 51 F8.4 deg DE2deg [-56.6/80] Source 2 Declination (J2000)
53- 60 F8.3 rad/m2 RM2 [-344.7/552] Source 2 rotation measure
62- 67 F6.3 rad/m2 e_RM2 [0.003/38] Uncertainty in RM2
69- 74 A6 --- Ref Reference bibcode (1)
76- 81 F6.4 --- z [0.026/3.14] Redshift of double radio source
82 A1 --- f_z [*] * = Reliable redshift information from
the original references
84- 88 F5.2 arcmin Deltar [0.1/40]? Angular separation of double radio
source
90- 93 I4 kpc LS [12/4404]? Projected linear separation of
double radio source
95-102 F8.3 rad/m2 DeltaRM [-726/539] Rotation measure difference
103 A1 --- f_DeltaRM [d] d=source removed from the final sample
used for the analysis
105-110 F6.3 rad/m2 e_DeltaRM [0.006/52.5] Uncertainty in DeltaRM
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Note (1): Reference as follows:
akm+98 = 1998A&A...329..809A 1998A&A...329..809A
bbh+07 = 2007, J/MNRAS/381/341
bowe19 = 2019MNRAS.482.5250B 2019MNRAS.482.5250B
ccsk92 = 1992ApJ...386..143C 1992ApJ...386..143C
gkb+04 = 2004MNRAS.347..508G 2004MNRAS.347..508G
hbb98 = 1998A&A...335.1117H 1998A&A...335.1117H
hbe09 = 2009A&A...503..409H 2009A&A...503..409H
ms96 = 1996ApJ...458..194M 1996ApJ...458..194M
obv+20 = 2020, J/MNRAS/495/2607
omv+19 = 2019A&A...622A..16O 2019A&A...622A..16O
opa+17 = 2017, J/MNRAS/469/4034
prm+89 = 1989AJ.....97..647P 1989AJ.....97..647P
rgs+20 = 2020, J/other/PASA/37.29
sc86 = 1986ApJ...310..160S 1986ApJ...310..160S
sob+20 = 2020A&A...638A..48S 2020A&A...638A..48S
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 deg RAdeg Source 1 Right Ascension (J2000)
10- 17 F8.4 deg DEdeg [-37.2/83] Source 1 Declination (J2000)
19- 26 F8.3 rad/m2 RM1 [-231.1/96] Source 1 rotation measure
28- 33 F6.3 rad/m2 e_RM1 [0.6/25.4] Uncertainty in RM1
35- 42 F8.4 deg RA2deg Source 2 Right Ascension (J2000)
44- 51 F8.4 deg DE2deg [-37.2/83] Source 2 Declination (J2000)
53- 60 F8.3 rad/m2 RM2 [-225/107.4] Source 2 rotation measure
62- 67 F6.3 rad/m2 e_RM2 [0.6/28.7] Uncertainty in RM2
69- 73 A5 --- Ref Reference code (tss09=2009, J/ApJ/702/1230)
75- 80 F6.4 --- z [0.003/5.2] Redshift of double radio source
82- 85 F4.2 arcmin Deltar [0.74/6.6] Angular separation of double
radio source
87- 90 I4 kpc LS [5/2835] Projected linear separation of
double radio source
92- 99 F8.3 rad/m2 DeltaRM [-102.4/49.8] Rotation measure difference
100-100 A1 --- f_DeltaRM [d] d=source removed from the final sample
used for the analysis
102-107 F6.3 rad/m2 e_DeltaRM [0.9/29.3] Uncertainty in DeltaRM
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Sep-2023