J/A+A/692/A12 LOFAR HBA observations of Perseus (van Weeren+, 2024)
LOFAR high-band antenna observations of the Perseus cluster.
The discovery of a giant radio halo.
van Weeren R.J., Timmerman R., Vaidya V., Gendron-Marsolais M.-L.,
Botteon A., Roberts I.D., Hlavacek-Larrondo J., Bonafede A., Bruggen M.,
Brunetti G., Cassano R., Cuciti V., Edge A.C., Gastaldello F.,
Groeneveld C., Shimwell T.W.
<Astron. Astrophys. 692, A12 (2024)>
=2024A&A...692A..12V 2024A&A...692A..12V (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, radio ; Radio sources ;
Active gal. nuclei
Keywords: radiation mechanisms: non-thermal - galaxies: active -
galaxies: clusters: intracluster medium -
galaxies: clusters: individual: Perseus cluster -
X rays: galaxies: clusters
Abstract:
The Perseus cluster is the brightest X-ray cluster in the sky and is
known as a cool-core galaxy cluster. Being a very nearby cluster, it
has been extensively studied. This has provided a comprehensive view
of the physical processes that operate in the intracluster medium
(ICM), including feedback from the active galactic nucleus (AGN) 3C 84
and measurements of ICM turbulence. Additionally, the Perseus cluster
contains a central radio mini-halo. This diffuse radio source traces
cosmic-ray electrons (re-)accelerated in situ in the ICM. Here, we
report on LOFAR high-band antenna 120-168MHz observations of the
Perseus cluster that probe a range of four orders of magnitude in
angular scales. In our 0.3" (0.11kpc) resolution image, we find that
the northern extension of the 3C 84 lobe consists of several narrow
1.5-3 kpc parallel strands of emission. In addition, we detect
steep-spectrum filaments associated with a previous outburst of the
central AGN radio emission filling two known X-ray "ghost" cavities.
At 7" resolution (2.6kpc), our images show a complex structured radio
mini-halo, with several edges and filaments. At resolutions of 26"
(10kpc) and 80" (29kpc), we discover diffuse radio emission with a
1.1Mpc extent. We classify this emission as a giant radio halo, and
its properties are distinct from the inner mini-halo. We also detect
two diffuse sources at projected cluster centric radii of 0.7 and
1.0Mpc. Finally, we observe a 0.9Mpc trail of radio emission from the
cluster member galaxy IC 310 that connects it to the giant radio halo.
Together with other recent studies of relaxed clusters, our LOFAR
observations indicate that cluster-wide radio emission could be (more)
common in cool-core clusters. In the case of the Perseus cluster, a
past off-axis merger event that preserved the cool core might have
generated enough turbulence to produce an extended radio halo
observable at low frequencies.
Description:
For the study of the Perseus Cluster, we used two LOFAR observations
within the 120-168MHz frequency range. The lower-resolution images
(7, 26, and 80 arcsec) were based on 8 hours of on-target observations
taken on November 3, 2016. For the higher-resolution images (0.3, 1.6,
3.4 arcsec), we utilized 8 hours of on-target observations from
December 14, 2018.
Objects:
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RA (2000) DE Designation(s)
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03 19 47.6 +41 30 54 Perseus Cluster = Abell 426
03 19 48.2 +41 30 42 3C84 = NGC 1275
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 122 8 List of fits images
fits/* . 8 Individual fits images
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See also:
J/A+A/440/151 : Observations at 850um in Perseus clusters (Hatchell+, 2005)
J/A+A/640/A30 : Galaxies in the Perseus cluster field (Meusinger+, 2020)
J/MNRAS/470/1512 : Faint LSB galaxy cand. in Perseus cluster (Wittmann+, 2017)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 50 A21 "datime" Obs.date Observation date
52- 58 F7.3 MHz Freq Observed frequency
60- 65 I6 Kibyte size Size of FITS file
67- 89 A23 --- FileName Name of FITS file, in subdirectory fits
91-122 A32 --- Title Title of the FITS file
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Acknowledgements:
Reinout van Weeren, rvweeren(at)strw.leidenuniv.nl
(End) Patricia Vannier [CDS] 06-Nov-2024