77 citations · 303 across the 23 of their papers we have counts for
24 papers
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…
The High-Energy Light Isotope eXperiment (HELIX) Instrument
P. S. Allison, M. Baiocchi, J. J. Beatty +27
The HELIX detector is a balloon-borne instrument designed to measure the flux of light (Z < 11) cosmic-ray isotopes. In this paper we describe the initial configuration of HELIX, o…
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…
On The Nonthermal Power Laws In Magnetized Turbulent Plasmas
Rostom Mbarek, Daniel Grošelj, Alexander Philippov
Building on recent progress in the understanding of particle transport in magnetized plasmas, we derive a scaling law for the formation of nonthermal spectral tails in mildly and s…
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 High Energy Light Isotope eXperiment program of direct cosmic-ray studies
HELIX Collaboration, S. Coutu, P. S. Allison +27
HELIX is a new NASA-sponsored instrument aimed at measuring the spectra and composition of light cosmic-ray isotopes from hydrogen to neon nuclei, in particular the clock isotopes…
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…
Relativistic Asymmetric Reconnection
Rostom Mbarek, Colby Haggerty, Lorenzo Sironi +2
We derive basic scaling equations for relativistic magnetic reconnection in the general case of asymmetric inflow conditions and obtain predictions for the outflow Lorentz factor a…
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…
Challenges to Constraining Exoplanet Masses via Transmission Spectroscopy
Natasha E. Batalha, Eliza M. -R. Kempton, Rostom Mbarek
MassSpec, a method for determining the mass of a transiting exoplanet from its transmission spectrum alone, was proposed by \citet{dew13}. The premise of this method relies on the…
Clouds in Super-Earth Atmospheres: Chemical Equilibrium Calculations
Rostom Mbarek, Eliza M. -R. Kempton
Recent studies have unequivocally proven the existence of clouds in super-Earth atmospheres (Kreidberg et al. 2014). Here we provide a theoretical context for the formation of supe…
"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…