J/A+A/661/A92 NGC 507 144-675MHz and X-ray images (Brienza+, 2022)
The galaxy group NGC 507:
newly detected AGN remnant plasma transported by sloshing.
Brienza M., Lovisari L., Rajpurohit K., Bonafede A., Gastaldello F.,
Murgia M., Vazza F., Bonnassieux E., Botteon A., Brunetti G., Drabent A.,
Hardcastle M.J., Pasini T., Riseley C.J., Rottgering H.J.A., Shimwell T.,
Simionescu A., van Weeren R.J.
<Astron. Astrophys. 661, A92 (2022)>
=2022A&A...661A..92B 2022A&A...661A..92B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Clusters, galaxy ; Radio continuum ;
X-ray sources
Keywords: galaxies: active - galaxies: groups: individual: NGC 507 -
galaxies: clusters: intracluster medium - galaxies: jets -
galaxies: interactions
Abstract:
Jets from active galactic nuclei (AGN) are known to recurrently enrich
their surrounding medium with mildly relativistic particles and
magnetic fields. Here, we present a detailed multi-frequency analysis
of the nearby (z=0.01646) galaxy group NGC 507. In particular, we
present new high-sensitivity and high-spatial-resolution radio images
in the frequency range 144-675 MHz obtained using Low Frequency Array
(LOFAR) and upgraded Giant Metrewave Radio Telescope (uGMRT)
observations. These reveal the presence of previously undetected
diffuse radio emission with complex, filamentary morphology likely
related to a previous outburst of the central galaxy. Based on
spectral ageing considerations, we find that the plasma was first
injected by the AGN 240-380Myr ago and is now cooling. Our analysis
of deep archival X-ray Multi-Mirror Mission XMM-Newton data confirms
that the system is dynamically disturbed, as previously suggested. We
detect two discontinuities in the X-ray surface-brightness
distribution (towards the east and south) tracing a spiral pattern,
which we interpret as cold fronts produced by sloshing motions. The
remarkable spatial coincidence observed between the newly detected
arc-like radio filament and the southern concave X-ray discontinuity
strongly suggests that the remnant plasma has been displaced by the
sloshing motions on large scales. Overall, NGC 507 represents one of
the clearest examples known to date in which a direct interaction
between old AGN remnant plasma and the external medium is observed in
a galaxy group. Our results are consistent with simulations that
suggest that filamentary emission can be created by the cluster or
group weather, disrupting AGN lobes and spreading their relativistic
content into the surrounding medium.
Description:
List of the main datasets used:
- Low Frequency Array (LOFAR) data at 150MHz from the LOFAR Two-metre
Sky Survey (LoTSS, see Shimwell et al., 2019A&A...622A...1S 2019A&A...622A...1S) reduced
with the LOTSS calibration strategy and further imaged with WSCLEAN
(Offringa et al., 2014MNRAS.444..606O 2014MNRAS.444..606O).
- Dedicated upgraded Giant Metrewave Radio Telescope (uGMRT)
observations at 400MHz and 675MHz processed with SPAM (Intema et al.,
2009A&A...501.1185I 2009A&A...501.1185I) and further imaged with WSCLEAN (Offringa et al.,
2014MNRAS.444..606O 2014MNRAS.444..606O).
- Archival XMM data (113ks) in the 0.3-14keV band reduced with the
XMM-Newton Science Analysis System (SAS).
Objects:
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RA (2000) DE Designation(s)
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01 23 39.906 +33 15 221.82 NGC 507 = MCG+05-04-044
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 115 4 List of fits images
fits/* . 4 Individual fits images
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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- 51 A22 "datime" Obs.date Observation date
53- 59 F7.3 MHz Freq ? Observed frequency
61- 64 I4 Kibyte size Size of FITS file
66- 83 A18 --- FileName Name of FITS file, in subdirectory fits
85-115 A31 --- Title Title of the FITS file
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Acknowledgements:
Marisa Brienza, m.brienza(at)ira.inaf.it
(End) Patricia Vannier [CDS] 14-Feb-2022