VLA Resolves Unexpected Radio Structures in the Perseus Cluster of Galaxies

Abstract

We present new deep, high-resolution, 1.5 GHz observations of the prototypical nearby Perseus galaxy cluster from the Karl G. Jansky Very Large Array. We isolate for the first time the complete tail of radio emission of the bent-jet radio galaxy NGC 1272, which had been previously mistaken to be part of the radio mini-halo. The possibility that diffuse radio galaxy emission contributes to mini-halo emission may be a general phenomenon in relaxed cool-core clusters, and should be explored. The collimated jets of NGC 1272 initially bend to the west, and then transition eastward into faint, 60 kpc long extensions with eddy-like structures and filaments. We suggest interpretations for these structures that involve bulk motions of intracluster gas, the galaxy’s orbit in the cluster including projection effects, and the passage of the galaxy through a sloshing cold front. Instabilities and turbulence created at the surface of this cold front and in the turbulent wake of the infalling host galaxy most likely play a role in the formation of the observed structures. We also discover a series of faint rings, southeast of NGC 1272, which are a type of structure that has never been seen before in galaxy clusters.

Multiphase turbulence in galactic haloes: effect of the driving

“…Although the gas motions in the ICM have been observed to be subsonic (Hitomi Collaboration 2016), the ICM/CGM is quite compressible, i.e., Mach numbers are of the order of 0.1-0.5. Moreover, we observe strong converging and diverging motions in these media -such as expanding X-ray cavities around AGN-inflated bubbles (Wise et al 2007;Biava et al 2021;Tiwari & Singh 2022), compressive waves during galaxy infall and passages (Churazov et al 2003(Churazov et al , 2021, gas sloshing and cold fronts (Botteon et al 2021;Gendron-Marsolais et al 2021;Ichinohe et al 2021;Ubertosi et al 2021;Ueda et al 2021;Brienza et al 2022), which indicate density contrasts and compressive motions in the ICM. Similarly, galactic outflows consisting of radially expanding motions driven by diverging flows such as stellar winds, supernova bubbles, super-bubbles and AGNs can also drive compressive motions in the disk-halo interface and the CGM (Mulcahy et al 2017;Das et al 2019;Tejos et al 2021).…”

The galaxy group NGC 507: Newly detected AGN remnant plasma transported by sloshing

“…Filamentary emission within non-thermal radio sources is starting to be commonly detected when high-angular-resolution, high-sensitivity observations are available. Examples of these features are found inside the lobes and tails of radio galaxies (see e.g., NGC 1272, Gendron-Marsolais et al 2021NGC 326, Hardcastle et al 2019;Fornax A Maccagni et al 2020;PKS 2014-55, Cotton et al 2020, as well as inside cluster radio relics (e.g., Abell 2256, Owen et al 2014;CIZA ,J2242.8+5301, Di Gennaro et al 2018RXS J0603.3+4214, Rajpurohit et al 2018), and radio phoenices (Mandal et al 2020). In the case of the lobes of radio galaxies, three-dimensional magnetohydrodynamics (MHD) simulations suggest that such filaments trace enhancements in the magnetic field distribution (e.g., Huarte-Espinosa et al 2011;Hardcastle 2013), which form as a consequence of the complex internal dynamics of the lobes.…”

A Candle in the Wind: A Radio Filament in the Core of the A3562 Galaxy Cluster

“…The turbulence needed to reaccelerate electrons within the core can be produced by sloshing in response to SC group passage (G05), as suggested for radio minihalos by ZuHone et al (2013a). In the latter work, the seed electrons were proposed to come from disrupted radio lobes of the central radio galaxy; those seeds could be supplied by an external radio galaxy as well (see also Gendron-Marsolais et al 2021;Biava et al 2021).…”