222 citations · 1.8k across the 66 of their papers we have counts for
32 papers · 1 filter
Fermi-eROSITA cross-correlations suggest annihilation lines of GeV WIMPs
Uri Keshet
The deep potential wells of galaxy clusters provide some of the strongest constraints on the velocity-dependent (-wave) annihilation of weakly interacting massive particle (WIMP…
Fermi bubbles detected in 100 TeV neutrinos
Uri Keshet, Ilya Gurwich
The Fermi bubbles have been identified as a collimated bipolar outflow emanating from the Milky-Way center, tracing strong forward shocks which extend kpc from the Galacti…
Nested Fermi and eROSITA bubbles require very similar erg collimated Galactic-center outbursts; their asymmetry indicates an eastern density gradient
Arka Ghosh, Uri Keshet, Santanu Mondal
Observations indicate two nested pairs of extended bipolar bubbles emanating from the Milky-Way center - the latitude eROSITA bubbles (RBs), encompassing the smal…
Mach shocks at the tips of both eROSITA bubbles
Uri Keshet, Arka Ghosh
eROSITA substantiated earlier indications that Loop-I is the northern part of an extended bipolar Galactic-bubble structure, but the southern bubble was not established in nontherm…
Cavitation instability in unmagnetized relativistic pair shocks
Ivan Demidov, Yuri Lyubarsky, Uri Keshet
We investigate the formation of plasma cavities in unmagnetized relativistic pair shocks and demonstrate that these cavities emerge naturally as a nonlinear consequence of asymmetr…
Galaxy-cluster-stacked Fermi-LAT III: substructure and radio-relic counterparts
Uri Keshet
Faint -ray signatures emerge in Fermi-LAT data stacked scaled to the characteristic radii of MCXC galaxy clusters. This third paper in a series shows a excess o…
Relativistic ions with power-law spectra explain radio phoenixes
Uri Keshet
Radio phoenixes are filamentary sources in the intracluster medium (ICM) of galaxy clusters, often extending over kpc, arising from fossil radio lobes. Their soft, curved sp…
Galaxy-cluster-stacked Fermi-LAT II: extended central hadronic signal
Uri Keshet
Faint -ray signatures emerge in Fermi-LAT data stacked scaled to the characteristic angles of MCXC galaxy clusters. After Paper I of this series thus discovered virial…
Macroscopic magnetization of primordial plasma by virial shocks
Uri Keshet, Kuan-Chou Hou
Galaxy-cluster virial (structure-formation accretion) shock observations are shown to imply magnetization of a layer extending Debye lengths downstrea…
Coma cluster -ray and radio emission is consistent with a secondary electron origin for the radio halo
Doron Kushnir, Uri Keshet, Eli Waxman
Observations of diffuse, non-thermal radio emission spanning several megaparsecs have been documented in over 100 galaxy clusters. This emission, classified as giant radio halos (G…
Galaxy cluster virial-shock sources in eROSITA catalogs
Gideon Ilani, Kuan-Chou Hou, Gil Nadler +1
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 relea…
Excess cataloged X-ray and radio sources at galaxy-cluster virial shocks
Gideon Ilani, Kuan-Chou Hou, Uri Keshet
We detect a highly significant excess of X-ray (2RXS) and radio (NVSS, GMRT, VLSSr) catalog sources when stacked around MCXC galaxy clusters and groups, narrowly confined within $\…
Fermi-bubble bulk and edge analysis reveals dust, cooling breaks, and cosmic-ray diffusion, facilitating a self-consistent model
Uri Keshet, Ilya Gurwich, Assaf Lavi +2
The full, radio to -ray spectrum of the Fermi bubbles is shown to be consistent with standard strong-shock electron acceleration at the bubble edge, without the unnatural energy…
Radio halos and relics from extended cosmic-ray ion distributions with strong diffusion in galaxy clusters
Uri Keshet
A joint hadronic model is shown to quantitatively explain the observations of diffuse radio emission from galaxy clusters in the form of minihalos, giant halos, relics, and their h…
Synchrotron emission from virial shocks around stacked OVRO-LWA galaxy clusters
Kuan-Chou Hou, Gregg Hallinan, Uri Keshet
Galaxy clusters accrete mass through large scale, strong, structure-formation shocks. Such a virial shock is thought to deposit fractions and of the thermal energy in c…
Nonlinear electromagnetic-wave interactions in pair plasma: (I) Non-relativistic regime
Arka Ghosh, Daniel Kagan, Uri Keshet +1
This paper is the first in a series devoted to the numerical study of nonlinear interactions of electromagnetic waves with plasma. We start with non-magnetized pair plasmas, where…
Fermi bubbles: the collimated outburst needed to explain forward-shock edges
Santanu Mondal, Uri Keshet, Kartick C. Sarkar +1
The bipolar, nonthermal, high-latitude lobes known as the Fermi bubbles (FBs) are thought to originate from a massive energy release near the Galactic centre (GC). We constrain the…
Maximally-hard spectra from diffusive shock-acceleration in pulsar-wind nebulae
Ofir Arad, Assaf Lavi, Uri Keshet
The processes leading to the exceptionally hard radio spectra of pulsar-wind nebulae (PWNe) are not yet understood. Radio photon spectral indices among PWNe from the literatur…
Diffusive shock acceleration in dimensions
Assaf Lavi, Ofir Arad, Yotam Nagar +1
Collisionless shocks are often studied in two spatial dimensions (2D), to gain insights into the 3D case. We analyze diffusive shock acceleration for an arbitrary number $N\in\math…
Advection by large-scale spiral flows in galaxy clusters
Yossi Naor, Uri Keshet
The intracluster medium of a galaxy cluster often shows an extended quasi-spiral structure, accentuated by tangential discontinuities known as cold fronts (CFs). These discontinuit…
Deprojecting galaxy-cluster cold fronts: evidence for bulk, magnetised spiral flows
Yossi Naor, Uri Keshet, Qian Wang +1
Tangential discontinuities known as cold fronts (CFs) are abundant in groups and clusters of galaxies (GCs). The relaxed, spiral-type CFs were initially thought to be isobaric, but…
Diffusive acceleration in relativistic shocks: particle feedback
Yotam Nagar, Uri Keshet
The spectral index of particles diffusively accelerated in a relativistic shock depends on the unknown angular diffusion function , which itself depends on the par…
Diffusive shock-acceleration: breakdown of spatial diffusion and isotropy
Uri Keshet, Ofir Arad, Yuri Lyubarski
We point out that particles accelerated in a non-relativistic shock of compression ratio attain the standard, spectral index only under certain conditions. Prev…
X-ray to gamma-ray virial shock signal from the Coma cluster
Uri Keshet, Ido Reiss
Following evidence for an east--west elongated virial ring around the Coma galaxy cluster in a GeV VERITAS mosaic, we search for corresponding signatures in GeV -ra…