77 citations · 303 across the 23 of their papers we have counts for
18 papers · 1 filter
Wind-Fed Magnetic Flux and the Emergence of X-ray Coronae in Active Galactic Nuclei
Rostom Mbarek
We propose a scenario for the onset of radiatively efficient Active Galactic Nuclei (AGN) in which circumnuclear stellar and supernova-driven winds supply mass and partially ordere…
First Detection of Radio Polarization During Jet Formation in the Changing-Look AGN 1ES 1927+654
Onic I. Shuvo, Eileen T. Meyer, Sibasish Laha +10
We present a multiwavelength radio study of the changing-look AGN 1ES 1927+654 following its renewed X-ray brightening since mid-2022, combining VLBA imaging with multi-band and ti…
The emergence of X-ray emission lines during relativistic radio-jet formation in the changing-look active galactic nucleus 1ES 1927+654
Dev R. Sadaula, Sibasish Laha, Eileen T. Meyer +27
We present results from a comprehensive multi-wavelength monitoring campaign of the changing-look active galactic nucleus 1ES 1927+654 during the onset and evolution of a relativis…
Hadronic Processes, Plasma Evolution and Neutrino Emission in Magnetic Towers of Neutron-Star Merger Remnants
Rostom Mbarek, Jiaxi Wu, Elias R. Most
Binary neutron star mergers can form short-lived magnetar-like remnants whose magnetically dominated polar towers reach --, but the microphysical…
Particle Acceleration, Coronal Neutrino Production, and the Diffuse Extragalactic Neutrino Background from Supermassive Black Holes
Rostom Mbarek
We present a generalized neutrino luminosity function for protons accelerated in the X-ray coronae of supermassive black holes in Seyfert-like galaxies. A major uncertainty in asse…
An outflow from the X-ray corona as the origin of millimeter emission from radio-quiet AGN
A. Hankla, A. Philippov, R. Mbarek +4
Recent observations of radio-quiet active galactic nuclei (RQAGN) have shown the presence of millimeter emission, whose origin remains unknown, from within parsec scales of the cen…
Revisiting Propagation Delays of Ultra-High-Energy Cosmic Rays from Long-lived Sources
Rostom Mbarek, Damiano Caprioli
We revisit the time delay incurred during ultra-high energy cosmic ray (UHECR) propagation over cosmological distances and its potential impact on the correlation between UHECR dir…
Multi-wavelength observations of a jet launch in real time from the post-changing-look Active Galaxy 1ES 1927+654
Sibasish Laha, Eileen T. Meyer, Dev R. Sadaula +34
We present results from a high cadence multi-wavelength observational campaign of the enigmatic changing look AGN 1ES 1927+654 from May 2022- April 2024, coincident with an unprece…
X-ray properties of coronal emission in radio quiet Active Galactic Nuclei
Sibasish Laha, Claudio Ricci, John C. Mather +5
Active galactic nuclei (AGN) are powerful sources of panchromatic radiation. All AGN emit in X-rays, contributing around of the AGN bolometric luminosity. The X-ray e…
A New Particle Pusher with Hadronic Interactions for Modeling Multimessenger Emission from Compact Objects
Minghao Zou, Hayk Hakobyan, Rostom Mbarek +3
We propose novel numerical schemes based on the Boris method in curved spacetime, incorporating both hadronic and radiative interactions for the first time. Once the proton has los…
Ultrahigh-energy neutrinos as a probe of espresso-shear acceleration in jets of Centaurus A
Rostom Mbarek, Damiano Caprioli, Kohta Murase
It has been suggested that Centaurus A (Cen A) could make a contribution to the observed ultrahigh-energy cosmic-ray (UHECR) flux. We calculate the flux of astrophysical neutrinos…
Late-time radio brightening and emergence of a radio jet in the changing-look AGN 1ES 1927+654
Eileen T. Meyer, Sibasish Laha, Onic I. Shuvo +32
We present multi-frequency (5-345 GHz) and multi-resolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic…
The Interplay between accelerated Protons, X-rays and Neutrinos in the Corona of NGC 1068: Constraints from Kinetic Plasma Simulations
Rostom Mbarek, Alexander Philippov, Alexander Chernoglazov +2
We examine properties of accelerated protons potentially responsible for the neutrino excess observed in the direction of NGC 1068, using constraints from kinetic Particle-in-Cell…
High-Energy Neutrino Emission from Espresso-Reaccelerated Ions in Jets of Active Galactic Nuclei
Rostom Mbarek, Damiano Caprioli, Kohta Murase
We present a bottom-up calculation of the flux of ultra-high energy cosmic rays (UHECRs) and high-energy neutrinos produced by powerful jets of active galactic nuclei (AGNs). By pr…
Ultra-High-Energy Cosmic Rays and Neutrinos from Relativistic Jets of Active Galactic Nuclei
Rostom Mbarek, Damiano Caprioli, Kohta Murase
In Mbarek & Caprioli (2019), we laid the groundwork for studying the espresso paradigm Caprioli (2015), a reacceleration mechanism to boost galactic CRs to UHECR levels. Our bottom…
Espresso and Stochastic Acceleration of Ultra-high-energy Cosmic Rays in Relativistic Jets
Rostom Mbarek, Damiano Caprioli
In the espresso scenario, ultra-high-energy (UHE) cosmic rays (CRs) are produced via a one-shot reacceleration of galactic-like CRs in the relativistic jets of active galactic nucl…
Bottom-up Acceleration of Ultra-High-Energy Cosmic Rays in the Jets of Active Galactic Nuclei
Rostom Mbarek, Damiano Caprioli
It has been proposed that Ultra-High-Energy Cosmic Rays (UHECRs) up to eV could be produced in the relativistic jets of powerful Active Galactic Nuclei (AGNs) via a one-sh…
"Espresso" Acceleration of Ultra-high-energy Cosmic Rays
Damiano Caprioli
We propose that ultra-high-energy (UHE) cosmic rays (CRs) above eV are produced in relativistic jets of powerful active galactic nuclei via an original mechanism, which we…