309 citations · 622 across the 48 of their papers we have counts for
46 papers · 1 filter
Investigating a TeV-Halo Candidate around PSR J1928+1746 with HAWC
The HAWC Collaboration, R. Alfaro, C. Alvarez +94
We present an updated High-Altitude Water Cherenkov (HAWC) analysis of the crowded Galactic-plane area near PSR J1928+1746, which was previously linked to the extended source 3HWC…
Observation of the Moon and Sun shadows with cosmic rays at an average energy of eV
The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu +346
Interactions of cosmic rays with the Moon and the Sun produce deficits in their arrival-direction distributions relative to an isotropic flux. Such shadows have been observed previ…
A Multiwavelength Interpretation of HESS J1857+026 Emission Using the Fermi-LAT, VERITAS, and HAWC Observatories
Jordan Eagle, Yu Chen, Ramiro Torres-Escobedo +2
We present a new study on the MeV-TeV gamma-ray origin of HESS J1857+026 using data collected from the Fermi-LAT, VERITAS, and HAWC observatories. A spatial and spectral study of H…
Constraints on axion-like particles from ultra-high-energy observations of M87 with the HAWC observatory
R. Alfaro, C. Alvarez, A. Andrés +95
In this work, we perform an indirect search for axion-like particles (ALPs) through their hypothesized mixing with photons in the presence of magnetic fields. ALPs are a well-motiv…
Constraining the Photon Intensity of Extragalactic Background Light with the HAWC Observatory for the Blazar Mrk 421
R. Alfaro, C. Alvarez, A. Andrés +79
The blazar Mrk 421 exhibits rapid variability over a wide range of timescales. Spectral differences have been observed during the different emission states of Mrk 421. During the h…
Depth of Maximum of Air-Shower Profiles above 10^17.7 eV Measured with the Fluorescence Detector of the Pierre Auger Observatory
The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu +358
We present measurements of the depth of shower maximum, Xmax, for cosmic-ray-induced extensive air showers recorded by the fluorescence detector of the Pierre Auger Observatory ove…
Search for TeV emission from spider millisecond pulsars with HAWC
R. Alfaro, E. Anita-Rangel, M. Araya +90
Millisecond pulsars (MSPs) are observed to emit multi-wavelength radiation, from radio to GeV. Spider MSPs, which interact with their low-mass companion in close orbit (orbital per…
A Multi-messenger Search for Ultra-high-energy Gamma Rays in Coincidence with Neutrinos
R. Alfaro, C. Alvarez, A. Andrés +101
The last five years have shown us that ultra-high-energy (UHE; 100 TeV) gamma-ray sources are ubiquitous, but the nature of these sources remain highly uncertain. UHE gamma rays…
HAWC Study on the Ultra-High-Energy Gamma-Ray Emissions from the Pulsar Wind Nebula G32.64+0.53
R. Alfaro, C. Alvarez, E. Anita-Rangel +91
Multi-TeV gamma-ray emission around eHWC J1850+001 (a source from the first HAWC catalog of gamma-ray sources emitting above 56 TeV) is spatially coincident with the pulsar wind ne…
Search for ultra-high energy neutrons from Galactic sources with the Pierre Auger Observatory
The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu +357
Deflections in the propagation of charged ultra-high-energy cosmic rays (UHECRs) caused by magnetic fields make the identification of their sources challenging. On the other hand,…
Investigating IceCube Neutrino Alerts with the HAWC -Ray Observatory
The HAWC Collaboration, R. Alfaro, C. Alvarez +95
Neutrino emission from astrophysical sources has long been considered a signature of cosmic-ray acceleration. The IceCube neutrino observatory has observed a diffuse flux of TeV-Pe…
Improved Heavy Dark Matter Annihilation Search from Dwarf Galaxies with HAWC
A. Albert, R. Alfaro, C. Alvarez +103
Understanding dark matter's elusive nature is crucial for the framework of particle physics and expanding the Standard Model. This analysis utilizes the High Altitude Water Cherenk…
The Fourth HAWC Catalog of Very-High-Energy Gamma-Ray Sources
R. Alfaro, C. Alvarez, E. Anita-Rangel +87
We present an updated catalog of TeV gamma-ray sources based on the fifth pass of data from the High-Altitude Water Cherenkov (HAWC) Observatory. This release benefits from improve…
Constraints on Axion-Like Particles from Ultra-High-Energy Observations of 3HWC J1908+063 with HAWC
R. Alfaro, C. Alvarez, A. Andres +92
Axion-like particles (ALPs) are hypothetical particles and compelling candidates for cold dark matter. Their existence could be probed through their conversions into photons in the…
Search for Signatures of Dark Matter Annihilation in the Galactic Center with HAWC
R. Alfaro, C. Alvarez, A. Andrés +109
We conduct an indirect dark matter (DM) search in the Galactic Center, focusing on a square region within in Galactic longitude and latutide, using 2,865 days of da…
Combined dark matter search towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS
LAT Collaboration, S. Abdollahi, L. Baldini +586
Dwarf spheroidal galaxies (dSphs) are excellent targets for indirect dark matter (DM) searches using gamma-ray telescopes because they are thought to have high DM content and a low…
HAWC, VERITAS, Fermi-LAT and XMM-Newton follow-up observations of the unidentified ultra-high-energy gamma-ray source LHAASO J2108+5157
The VERITAS collaboration, C. B. Adams, P. Bangale +142
We report observations of the ultra-high-energy gamma-ray source LHAASO J21085157, utilizing VERITAS, HAWC, Fermi-LAT, and XMM-Newton. VERITAS has collected 40 hours of d…
The Scintillator Surface Detector of the Pierre Auger Observatory
The Pierre Auger Collaboration
Data collected so far by the Pierre Auger Observatory have enabled major advances in ultra-high energy cosmic ray physics and demonstrated that improved determination of masses of…
The Pierre Auger Observatory: Contributions to the 39th International Cosmic Ray Conference (ICRC 2025)
The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu +352
The Pierre Auger Observatory, located in La Pampa Amarilla, Argentina, has been continuously acquiring data since 2004. It comprises a surface detector array covering 3,000 km…
Science Prospects for the Southern Wide-field Gamma-ray Observatory: SWGO
SWGO Collaboration, P. Abreu, R. Alfaro +303
Ground-based gamma-ray astronomy is now well established as a key observational approach to address critical topics at the frontiers of astroparticle physics and high-energy astrop…
Longtime Monitoring of TeV Radio Galaxies with HAWC
R. Alfaro, C. Alvarez, E. Anita-Rangel +85
We present the monitoring of the TeV-emitting radio galaxies M87, NGC~1275, 3C~264, and IC~310 with the High Altitude Water Cherenkov Observatory (HAWC) over a period of approximat…
The Energy Spectrum of Ultra-High Energy Cosmic Rays across Declinations to as measured at the Pierre Auger Observatory
The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu +360
The energy spectrum of cosmic rays above 2.5 EeV has been measured across the declination range using data from events accrued at…
Absence of TeV halos around millisecond pulsars
A. U. Abeysekara, R. Alfaro, C. Alvarez +82
TeV halos are extended very-high-energy (VHE; 0.1-100 TeV) gamma-ray emission around middle-aged pulsars. So far they have only been found around isolated pulsars, but it has been…
Extended TeV Halos May Commonly Exist around Middle-Aged Pulsars
A. Albert, R. Alfaro, C. Alvarez +81
Extended gamma-ray emission around isolated pulsars at TeV energies, also known as TeV halos, have been found around a handful of middle-aged pulsars. The halos are significantly m…