M. A. DuVernois
A5064093554- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Radiation Detection and Scintillator Technologies
- Solar and Space Plasma Dynamics
- Radiation Therapy and Dosimetry
- Radio Wave Propagation Studies
- Particle Accelerators and Free-Electron Lasers
- Atmospheric Ozone and Climate
- Ionosphere and magnetosphere dynamics
- Astrophysical Phenomena and Observations
- Computational Physics and Python Applications
- Gyrotron and Vacuum Electronics Research
- Particle accelerators and beam dynamics
- Cryospheric studies and observations
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Precipitation Measurement and Analysis
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
University of Wisconsin–Madison
2016-2025
Lawrence Berkeley National Laboratory
2023-2024
Southern University and Agricultural and Mechanical College
2021-2024
Clark Atlanta University
2021-2024
The University of Texas at Arlington
2021-2024
University of Alaska Anchorage
2021-2024
Providence College
2021-2024
Universidad Nacional Autónoma de México
2023
UCLouvain
2023
Energy Center of Wisconsin
2014-2023
Exotic origin for cosmic positrons Several cosmic-ray detectors have found more arriving at Earth than expected. Some researchers interpret this as a signature of exotic physics, such the annihilation dark matter particles. Others prefer mundane explanation that involves positron generation pulsars followed by diffusion to Earth. Abeysekara et al. detected extended emission gamma rays around two nearby pulsars, generated high-energy electrons and positrons. The size was used calculate how...
The Crab Nebula is the brightest TeV gamma-ray source in sky and has been used for past 25 years as a reference astronomy, calibration verification of new instruments. High Altitude Water Cherenkov Observatory (HAWC), completed early 2015, to observe at high significance across nearly full spectrum energies which HAWC sensitive. unique its wide field-of-view, 2 sr any instant, high-energy reach, up 100 TeV. HAWC's sensitivity improves with energy. Above $\sim$1 driven by best background...
We present the first catalog of TeV gamma-ray sources realized with recently completed High Altitude Water Cherenkov Observatory (HAWC). It is most sensitive wide field-of-view telescope currently in operation, a 1-year survey sensitivity ~5-10% flux Crab Nebula. With an instantaneous field view >1.5 sr and >90% duty cycle, it continuously surveys monitors sky for gamma ray energies between hundreds GeV tens TeV. HAWC located Mexico at latitude 19 degree North was March 2015. Here, we 2HWC...
The IceCube Neutrino Observatory has established the existence of a high-energy all-sky neutrino flux astrophysical origin. This discovery was made using events interacting within fiducial region detector surrounded by an active veto and with reconstructed energy above 60 TeV, commonly known as starting event sample, or HESE. We revisit analysis HESE sample additional 4.5 years data, newer glacial ice models, improved systematics treatment. paper describes in detail, reports on latest...
We report three searches for high energy neutrino emission from astrophysical objects using data recorded with IceCube between 2011 and 2020. Improvements over previous work include new reconstruction calibration methods. In one search, the positions of 110 a priori selected gamma-ray sources were analyzed individually possible surplus neutrinos atmospheric cosmic background expectations. found an excess $79_{-20}^{+22}$ associated nearby active galaxy NGC 1068 at significance 4.2$\,\sigma$....
The balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment launched five times from Antarctica has achieved a cumulative flight duration of about 156 days above 99.5% the atmosphere. instrument is configured with complementary and redundant particle detectors designed to extend direct measurements cosmic-ray composition highest energies practical balloon flights. All elements protons iron nuclei are separated excellent charge resolution. Here we report results first two flights ~70...
Cosmic-ray proton and helium spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass experiment flown for 42 days in Antarctica 2004–2005 austral summer season. High-energy cosmic-ray data were collected at an average altitude of ∼38.5 km atmospheric overburden ∼3.9 g cm−2. Individual elements are clearly separated a charge resolution ∼0.15 e (in units) ∼0.2 protons nuclei, respectively. The top atmosphere represented by power laws spectral index −2.66 ± 0.02 from...
We present the first catalog of gamma-ray sources emitting above 56 and 100 TeV with data from High Altitude Water Cherenkov (HAWC) Observatory, a wide field-of-view observatory capable detecting gamma rays up to few hundred TeV. Nine are observed TeV, all which likely Galactic in origin. Three continue past making this highest-energy source date. report integral flux each these objects. also spectra for three discuss possibility that they PeVatrons.
The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, has been a mystery for over century. Due to deflection in interstellar magnetic fields, rays from the Milky Way arrive at Earth random directions. However, near their sources and during propagation, interact with matter produce neutrinos. We search neutrino emission using machine learning techniques applied ten years data IceCube Neutrino Observatory. identify Galactic plane 4.5$σ$ level...
Abstract We present TeV gamma-ray observations of the Crab Nebula, standard reference source in ground-based astronomy, using data from High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy estimation methods that utilize extensive air shower variables such as core position, angle, and lateral distribution. contrast, previously published HAWC spectrum roughly estimated with only number photomultipliers triggered. This new methodology...
Abstract We present a measurement of the high-energy astrophysical muon–neutrino flux with IceCube Neutrino Observatory. The uses high-purity selection 650k neutrino-induced muon tracks from northern celestial hemisphere, corresponding to 9.5 yr experimental data. With respect previous publications, is improved by increased size event sample and extended model testing beyond simple power-law hypotheses. An updated treatment systematic uncertainties atmospheric background fluxes has been...
This article presents the design of Radio Neutrino Observatory Greenland (RNO-G) and discusses its scientific prospects. Using an array radio sensors, RNO-G seeks to measure neutrinos above 10 PeV by exploiting Askaryan effect in neutrino-induced cascades ice. We discuss experimental considerations that drive RNO-G, present first measurements hardware is be deployed projected sensitivity instrument. will production-scale detector for in-ice neutrino signals.
Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations yet detected between neutrinos and GRBs, the recent observation GRB 221009A - brightest observed by Fermi-GBM to date first one be above an energy 10 TeV provides unique opportunity test for hadronic emission. In this paper, we leverage wide range IceCube Neutrino Observatory search from 221009A. We find significant deviation background expectation across event samples ranging...
Measurements of the energy spectra negative electrons and positrons have been performed with High-Energy Antimatter Telescope (HEAT) in two balloon flights—1994 May from Fort Sumner, NM, 1995 August Lynn Lake, Manitoba. We present combined data set these flights, covering range 1-100 GeV. compare our results other groups discuss context diffusive propagation models. There is some evidence that primary above 10 GeV cosmic-ray nuclei exhibit same spectrum at source, but source becomes harder...
We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with balloon-borne HEAT-pbar instrument in spring 2000. The data presented here are compatible our previous measurements, obtained different instrument. combined from three HEAT flights indicate small flux nonstandard origin above GeV. compare earlier HEAT-e(+/-) instrument, during opposite epoch solar cycle, conclude that measurements do not support predictions charge sign dependent modulation abundance
The Antarctic Impulsive Transient Antenna (ANITA) completed its second long-duration balloon flight in January 2009, with 31 days aloft (28.5 live days) over Antarctica. ANITA searches for impulsive coherent radio Cherenkov emission from 200 to 1200 MHz, arising the Askaryan charge excess ultra-high energy neutrino-induced cascades within ice. This included significant improvements first payload sensitivity, efficiency, and a trajectory deeper Analysis of in-flight calibration pulses surface...
We report new limits on cosmic neutrino fluxes from the test flight of Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day a prototype long-duration balloon payload, called ANITA-lite, in early 2004. search for impulsive events that could be associated with ultrahigh energy interactions ice and derive constrain several models rule out long-standing -burst model.
We report on observations of coherent, impulsive radio Cherenkov radiation from electromagnetic showers in solid ice. This is the first observation Askaryan effect As part complete validation process for ANITA experiment, we performed an experiment at Stanford Linear Accelerator Center June 2006 using a 7.5 metric ton ice target. measure time large-scale angular dependence pattern, major factor determining solid-angle acceptance ultrahigh-energy neutrino detectors.
We report the observation of 16 cosmic ray events with a mean energy $1.5\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }\text{ }\mathrm{eV}$ via radio pulses originating from interaction air shower Antarctic geomagnetic field, process known as geosynchrotron emission. present measurements in 300--900 MHz range, which are first self-triggered, ultrawide band, far-field, and highest sample collected technique. Their properties inconsistent current ground-based models. The emission is 100%...
We present new measurements of the energy spectra cosmic-ray (CR) nuclei from second flight balloon-borne experiment Cosmic-Ray Energetics And Mass (CREAM). The instrument included different particle detectors to provide redundant charge identification and measure CRs up several hundred TeV. measured individual C, O, Ne, Mg, Si, Fe are presented ∼1014 eV. spectral shape looks nearly same for these primary elements it can be fitted an E−2.66 ± 0.04 power law in energy. Moreover, a measurement...