Related papers: X-ray to gamma-ray virial shock signal from the Co…
Galaxy clusters are thought to grow by accreting mass through large-scale, strong, yet elusive, virial shocks. Such a shock is expected to accelerate relativistic electrons, thus generating a spectrally-flat leptonic virial-ring. However,…
The presence of relativistic electrons within the diffuse gas phase of galaxy clusters is now well established, but their detailed origin remains unclear. Cosmic ray protons are also expected to accumulate during the formation of clusters…
In the hierarchical paradigm of structure formation, galaxy clusters are the largest objects ever to virialize. They are thought to grow by accreting mass through large scale, strong virial shocks. Such a collisionless shock is expected to…
Galaxy clusters, the largest gravitationally bound objects in the Universe, are thought to grow by accreting mass from their surroundings through large-scale virial shocks. Due to electron acceleration in such a shock, it should appear as a…
Many galaxy clusters have giant halos of non-thermal radio emission, indicating the presence of relativistic electrons in the clusters. Relativistic protons may also be accelerated by merger and/or accretion shocks in galaxy clusters. These…
Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated, suggesting that clusters may also be sources of very high-energy (VHE; E>100 GeV) gamma-ray…
Faint $\gamma$-ray signatures emerge in Fermi-LAT data stacked scaled to the characteristic $\theta_{500}$ angles of MCXC galaxy clusters. After Paper I of this series thus discovered virial shocks, later supported in other bands, this…
Clusters of galaxies are one of the few prominent classes of objects predicted to emit gamma rays not yet detected by satellites like EGRET or ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs). The detection of Very High Energy…
Virial shocks around galaxy clusters are expected to show a cutoff in the thermal Sunyaev-Zel'dovich (SZ) signal, coincident with a leptonic ring. However, until now, leptonic virial signals were reported only in Coma and in stacked…
Galaxy clusters can be sources of high-energy (HE) $\gamma$-ray radiation, due to the efficient acceleration of particles exceeding EeV energies. At present, though, the only candidate for emitting HE $\gamma$-rays is the Coma cluster,…
This is the second paper in a series of studies of the Coma cluster using the SRG/eROSITA X-ray data obtained during the calibration and performance verification phase of the mission. Here, we focus on the region adjacent to the radio…
Galaxy clusters are the most massive gravitationally bound structures in the Universe. Even if clusters are nearly virialized structures, they undergo merging processes, creating merging shocks, and suffer from feedback from galaxies and…
RASS data near the North Galactic Pole was analyzed in order to study the large-scale distribution of soft X-ray emission from the Coma cluster. These RASS data constitute the only available X-ray observations of Coma that feature an in…
We report evidence for extended gamma-ray emission from the Virgo, Fornax and Coma clusters based on a maximum-likelihood analysis of the 3-year Fermi-LAT data. For all three clusters, excess emission is observed within three degrees of the…
Following the recent identification of discrete ROSAT and radio sources associated with the virial shocks of MCXC clusters and groups, we examine if the early eROSITA-DE data release (EDR) shows virial-shock X-ray sources within its $140$…
Faint $\gamma$-ray signatures emerge in Fermi-LAT data stacked scaled to the characteristic $R_{500}$ radii of MCXC galaxy clusters. This third paper in a series shows a $4.3\sigma$ excess of discrete 4FGL-DR4 catalog $\gamma$-ray sources…
We present results of X-ray observations of the Coma cluster with multiple instruments over a broad energy band. Using the data from INTEGRAL, RXTE and ROSAT observatories, we find that the Coma spectrum in the 0.5-107 keV energy band can…
We present results from {\gamma}-ray observations of the Coma cluster incorporating 6 years of Fermi-LAT data and the newly released {\emph{Pass 8}} event-level analysis. Our analysis of the region reveals low-significance residual…
The supersonic flow motions associated with infall of baryonic gas toward sheets and filaments, as well as cluster mergers, produces large-scale shock waves. The shocks associated with galaxy clusters can be classified mainly into two…
Cosmic-ray (CR) sources temporarily enhance the relativistic particle density in their vicinity over the background distribution accumulated from the Galaxy-wide past injection activity and propagation. If individual sources are close…