J/A+A/680/A31 Radio relics in LoTSS-DR2 and PSZ2 (Jones+, 2023)
The Planck clusters in the LOFAR sky.
VI. LoTSS-DR2: Properties of radio relics.
Jones A., de Gasperin F., Cuciti V., Botteon A., Zhang X., Gastaldello F.,
Shimwell T., Simionescu A., Rossetti M., Cassano R., Akamatsu H.,
Bonafede A., Brueggen M., Brunetti G., Camillini L., Di Gennaro G.,
Drabent A., Hoang D.N., Rajpurohit K., Natale R., Tasse C.,
van Weeren R.J.
<Astron. Astrophys. 680, A31 (2023)>
=2023A&A...680A..31J 2023A&A...680A..31J (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Radio continuum ; Radio sources ; Surveys
Keywords: galaxies: clusters: general -
galaxies: clusters: intracluster medium -
radiation mechanisms: nonthermal - radiation mechanisms: thermal -
catalogs
Abstract:
It is well-established that shock waves in the intracluster medium
launched by galaxy cluster mergers can produce synchrotron emission,
which is visible to us at radio frequencies as radio relics. However,
the particle acceleration mechanism producing these relics is still
not fully understood. It is also unclear how relics relate to radio
halos, which trace merger-induced turbulence in the intracluster
medium.
We aim to perform the first statistical analysis of radio relics in a
mass-selected sample of galaxy clusters, using homogeneous
observations.
We analysed all relics observed by the Low Frequency Array Two Metre
Sky Survey Data Release 2 (LoTSS DR2) at 144 MHz, hosted by galaxy
clusters in the second Planck catalogue of SZ sources (PSZ2). We
measured and compared the relic properties in a uniform, unbiased way.
In particular, we developed a method to describe the characteristic
downstream width in a statistical manner. Additionally, we searched
for differences between radio relic-hosting clusters with and without
radio halos.
We find that, in our sample, ∼10% of galaxy clusters host at least one
radio relic. We confirm previous findings, at higher frequencies, of a
correlation between the relic-cluster centre distance and the longest
linear size, as well as the radio relic power and cluster mass.
However, our findings suggest that we are still missing a population
of low-power relics. We also find that relics are wider than
theoretically expected, even with optimistic downstream conditions.
Finally, we do not find evidence of a single property that separates
relic-hosting clusters with and without radio halos.
Description:
The attached FITS files contain radio and x-ray (where available)
images of the galaxy clusters in the second LOFAR Two-metre Sky Survey
Data Release (LoTSS-DR2) and in the second Planck catalog of
Sunyaev-Zel'dovich sources (PSZ2) identified as containing one or more
radio relics. The relevant LoTSS-DR2 observations were reprocessed to
produce 144 MHz radio images with point sources subtracted and with a
50 kpc uv-taper. The X-ray images were produced from processed
archival Chandra/XMM-Newton data and smoothed to 30 kpc at the target
cluster redshift.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 36 26 List of studied sources
list.dat 137 46 List of fits images
fits/* . 46 Individual fits images
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See also:
https://lofar-surveys.org/planck_dr2.html :
The Planck clusters in the LOFAR sky project website
Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name Name, PSZ2 GLLL.ll+BB.bb
21- 28 F8.4 deg RAdeg Right ascension (J2000)
30- 36 F7.4 deg DEdeg Declination (J2000)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
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- 62 E11.6 Hz Freq ? Observed frequency
64- 68 I5 Kibyte size Size of FITS file
70- 98 A29 --- FileName Name of FITS file, in subdirectory fits
100-117 A18 --- Name Name, PSZ2 GLLL.ll+BB.bb
119-137 A19 --- Title Title of the FITS file
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Acknowledgements:
Alexander Jones, ajones(at)hs.uni-hamburg.de
Andrea Botteon, botteon(at)strw.leidenuniv.nl
References:
Botteon et al., Paper I 2022A&A...660A..78B 2022A&A...660A..78B, Cat. J/A+A/660/A78
(End) Patricia Vannier [CDS] 22-Jan-2023