Publications (72)
Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
A. U. Abeysekara, A. Albert, R. Alfaro +113
The unexpectedly high flux of cosmic ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary prod…
Very high energy particle acceleration powered by the jets of the microquasar SS 433
HAWC Collaboration, A. U. Abeysekara, A. Albert +104
SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star). Two jet…
-ray Emission from Classical Nova V392 Per: Measurements from Fermi and HAWC
A. Albert, R. Alfaro, C. Alvarez +84
This paper reports on the -ray properties of the 2018 Galactic nova V392 Per, spanning photon energies 0.1 GeV to 100 TeV by combining observations from the Fermi Gamma-r…
HAWC J2227+610 and its association with G106.3+2.7, a new potential Galactic PeVatron
A. Albert, R. Alfaro, C. Alvarez +97
We present the detection of VHE gamma-ray emission above 100 TeV from HAWC J2227+610 with the HAWC observatory. Combining our observations with previously published results by VERI…
HAWC Contributions to the 35th International Cosmic Ray Conference (ICRC2017)
A. U. Abeysekara, A. Albert, R. Alfaro +123
List of proceedings from the HAWC Collaboration presented at the 35th International Cosmic Ray Conference, 12 July - 20 July 2017, Bexco, Busan, Korea.
Observation of the Galactic Center PeVatron Beyond 100 TeV with HAWC
A. Albert, R. Alfaro, C. Alvarez +99
We report an observation of ultra-high energy (UHE) gamma rays from the Galactic Center region, using seven years of data collected by the High-Altitude Water Cherenkov (HAWC) Obse…
Probing the Sea of Cosmic Rays by Measuring Gamma-Ray Emission from Passive Giant Molecular Clouds with HAWC
A. Albert, R. Alfaro, C. Alvarez +87
The study of high-energy gamma rays from passive Giant Molecular Clouds (GMCs) in our Galaxy is an indirect way to characterize and probe the paradigm of the "sea" of cosmic rays i…
Gamma/Hadron Separation with the HAWC Observatory
R. Alfaro, C. Alvarez, J. D. Ãlvarez +90
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory observes atmospheric showers produced by incident gamma rays and cosmic rays with energy from 300 GeV to more than 10…
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…
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…
3HWC: The Third HAWC Catalog of Very-High-Energy Gamma-ray Sources
A. Albert, R. Alfaro, C. Alvarez +104
We present a new catalog of TeV gamma-ray sources using 1523 days of data from the High Altitude Water Cherenkov (HAWC) observatory. The catalog represents the most sensitive surve…
Constraints on Spin-Dependent Dark Matter Scattering with Long-Lived Mediators from TeV Observations of the Sun with HAWC
A. Albert, R. Alfaro, C. Alvarez +91
We analyze the Sun as a source for the indirect detection of dark matter through a search for gamma rays from the solar disk. Capture of dark matter by elastic interactions with th…
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 +90
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…
Science Case for a Wide Field-of-View Very-High-Energy Gamma-Ray Observatory in the Southern Hemisphere
A. Albert, R. Alfaro, H. Ashkar +100
We outline the science motivation for SGSO, the Southern Gamma-Ray Survey Observatory. SGSO will be a next-generation wide field-of-view gamma-ray survey instrument, sensitive to g…
Constraints on Lorentz invariance violation from HAWC observations of gamma rays above 100 TeV
HAWC Collaboration, A. Albert, R. Alfaro +90
Due to the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV…
Galactic Gamma-Ray Diffuse Emission at TeV energies with HAWC Data
R. Alfaro, C. Alvarez, J. C. Arteaga-Velazquez +77
The Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons and electrons, interacting with gas and electromagnetic radiation fields i…
Spectrum and Morphology of the Very-High-Energy Source HAWC J2019+368
HAWC Collaboration, A. Albert, R. Alfaro +80
The MGRO J2019+37 region is one of the brightest sources in the sky at TeV energies. It was detected in the 2 year HAWC catalog as 2HWC J2019+367 and here we present a detailed stu…
A Search for Dark Matter in the Galactic Halo with HAWC
A. U. Abeysekara, A. M. Albert, R. Alfaro +100
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field-of-view observatory sensitive to 500 GeV - 100 TeV gamma rays and cosmic rays. With its observations…
Limits on the Diffuse Gamma-Ray Background above 10 TeV with HAWC
HAWC Collaboration, A. Albert, R. Alfaro +87
The high-energy Diffuse Gamma-Ray Background (DGRB) is expected to be produced by unresolved isotropically distributed astrophysical objects, potentially including dark matter anni…
Search for Very High Energy Gamma Rays from the Northern Bubble Region with HAWC
A. U. Abeysekara, A. Albert, R. Alfaro +108
We present a search of very high energy gamma-ray emission from the Northern Bubble region using data collected with the High Altitude Water Cherenkov (HAWC) gamma…
Multiple Galactic Sources with Emission Above 56 TeV Detected by HAWC
HAWC Collaboration, A. U. Abeysekara, A. Albert +99
We present the first catalog of gamma-ray sources emitting above 56 and 100 TeV with data from the High Altitude Water Cherenkov (HAWC) Observatory, a wide field-of-view observator…
Search for joint multimessenger signals from potential galactic cosmic-ray accelerators with HAWC and IceCube
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez +489
The origin of high-energy galactic cosmic rays is yet to be understood, but some galactic cosmic-ray accelerators can accelerate cosmic rays up to PeV energies. The high-energy cos…
Search for Gamma-Ray and Neutrino Coincidences Using HAWC and ANTARES Data
H. A. Ayala Solares, S. Coutu, D. Cowen +228
In the quest for high-energy neutrino sources, the Astrophysical Multimessenger Observatory Network (AMON) has implemented a new search by combining data from the High Altitude Wat…
Detailed Analysis of the TeV γ-Ray Sources 3HWC J1928+178, 3HWC J1930+188, and the New Source HAWC J1932+192
A. Albert, R. Alfaro, C. Alvarez +91
The latest High Altitude Water Cherenkov (HAWC) point-like source catalog up to 56 TeV reported the detection of two sources in the region of the Galactic plane at galactic longitu…
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…
HAWC observations of the acceleration of very-high-energy cosmic rays in the Cygnus Cocoon
A. U. Abeysekara, A. Albert, R. Alfaro +98
Cosmic rays with energies up to a few PeV are known to be accelerated within the Milky Way. Traditionally, it has been presumed that supernova remnants were the main source of very…
Invited Article: miniTimeCube
V. A. Li, R. Dorrill, M. J. Duvall +16
We present the development of the miniTimeCube (mTC), a novel compact neutrino detector. The mTC is a multipurpose detector, aiming to detect not only neutrinos but also fast/therm…
Performance of the HAWC Observatory and TeV Gamma-Ray Measurements of the Crab Nebula with Improved Extensive Air Shower Reconstruction Algorithms
A . Albert, R. Alfaro, C. Alvarez +90
The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory located on the side of the Sierra Negra volcano in Mexico, has been fully operational since 2015. The HAWC collaborat…
HAWC Contributions to the 34th International Cosmic Ray Conference (ICRC2015)
HAWC Collaboration, A. U. Abeysekara, R. Alfaro +112
List of proceedings from the HAWC Collaboration presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.
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…
Observation of Anisotropy of TeV Cosmic Rays with Two Years of HAWC
A. U. Abeysekara, R. Alfaro, C. Alvarez +98
After two years of operation, the High-Altitude Water Cherenkov (HAWC) Observatory has analyzed the TeV cosmic-ray sky over an energy range between and TeV. The HAWC d…
Search for Dark Matter Gamma-ray Emission from the Andromeda Galaxy with the High-Altitude Water Cherenkov Observatory
A. Albert, R. Alfaro, C. Alvarez +97
The Andromeda Galaxy (M31) is a nearby (780 kpc) galaxy similar to our own Milky Way. Observational evidence suggests that it resides in a large halo of dark matter (DM), mak…
MAGIC and Fermi-LAT gamma-ray results on unassociated HAWC sources
M. L. Ahnen, S. Ansoldi, L. A. Antonelli +336
The HAWC Collaboration released the 2HWC catalog of TeV sources, in which 19 show no association with any known high-energy (HE; E > 10 GeV) or very-high-energy (VHE; E > 300 GeV)…
The HAWC real-time flare monitor for rapid detection of transient events
A. U. Abeysekara, R. Alfaro, C. Alvarez +105
We present the development of a real-time flare monitor for the High Altitude Water Cherenkov (HAWC) observatory. The flare monitor has been fully operational since 2017 January an…
Evidence of 200 TeV photons from HAWC J1825-134
A. Albert, R. Alfaro, C. Alvarez +81
The Earth is bombarded by ultra-relativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=10 eV), the knee in the particle spectrum, are believ…
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…
Testing the Molecular Cloud Paradigm for Ultra-High-Energy Gamma Ray Emission from the Direction of SNR G106.3+2.7
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez +87
Supernova remnants (SNRs) are believed to be capable of accelerating cosmic rays (CRs) to PeV energies. SNR G106.3+2.7 is a prime PeVatron candidate. It is formed by a head region,…
Daily monitoring of TeV gamma-ray emission from Mrk 421, Mrk 501, and the Crab Nebula with HAWC
A. U. Abeysekara, A. Albert, R. Alfaro +104
We present results from daily monitoring of gamma rays in the energy range to TeV with the first 17 months of data from the High Altitude Water Cherenkov (HAWC)…
Evidence that Ultra-High-Energy Gamma Rays are a Universal Feature Near Powerful Pulsars
HAWC Collaboration, A. Albert, R. Alfaro +97
The highest-energy known gamma-ray sources are all located within 0.5 degrees of extremely powerful pulsars. This raises the question of whether ultra-high-energy (UHE; 56 TeV)…
HAWC Performance Enhanced by Machine Learning in Gamma-Hadron Separation
R. Alfaro, C. Alvarez, A. Andrés +92
Improving gamma-hadron separation is one of the most effective ways to enhance the performance of ground-based gamma-ray observatories. With over a decade of continuous operation,…
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…
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…
Constraints on the very high energy gamma-ray emission from short GRBs with HAWC
A. Albert, R. Alfaro, C. Alvarez +87
Many gamma-ray bursts (GRBs) have been observed from radio wavelengths, and a few at very-high energies (VHEs, > 100GeV). The HAWC gamma-ray observatory is well suited to study tra…
Orbital Modulation of Gamma-Rays Beyond 100 TeV from LS 5039
R. Alfaro, M. Araya, J. C. Arteaga-Velázquez +88
Gamma-ray binaries are systems composed of a compact object orbiting a massive companion star. The interaction between these two objects can drive relativistic outflows, either jet…
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…
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…
A Contribution of the HAWC Observatory to the TeV era in the High Energy Gamma-Ray Astrophysics: The case of the TeV-Halos
Ramiro Torres-Escobedo, Hao Zhou, Eduardo de la Fuente +130
We present a short overview of the TeV-Halos objects as a discovery and a relevant contribution of the High Altitude Water Äerenkov (HAWC) observatory to TeV astrophysics. We disc…
The High-Altitude Water Cherenkov (HAWC) Observatory in México: The Primary Detector
A. U. Abeysekara, A. Albert, R. Alfaro +140
The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analy…
TeV emission of Galactic plane sources with HAWC and H.E.S.S
H. Abdalla, F. Aharonian, F. Ait Benkhali +318
The High Altitude Water Cherenkov (HAWC) observatory and the High Energy Stereoscopic System (H.E.S.S.) are two leading instruments in the ground-based very-high-energy gamma-ray d…
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…
Study of long-term spectral evolution and X-ray and Gamma-ray correlation of blazars seen by HAWC
R. Alfaro, C. Alvarez, A. Andrés +94
The HAWC Observatory collected 6 years of extensive data, providing an ideal platform for long-term monitoring of blazars in the Very High Energy (VHE) band, without bias towards s…
HAWC Study of Very-High-Energy -ray Spectrum of HAWC J1844-034
HAWC Collaboration, A. Albert, C. Alvarez +74
Recently, the region surrounding eHWC J1842-035 has been studied extensively by gamma-ray observatories due to its extended emission reaching up to a few hundred TeV and potential…
VERITAS and Fermi-LAT observations of new HAWC sources
VERITAS Collaboration, A. U. Abeysekara, A. Archer +280
The HAWC (High Altitude Water Cherenkov) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100~GeV) gamma-ray sources based on 507 days of obs…
Constraints on the Emission of Gamma Rays from M31 with HAWC
HAWC Collaboration, A. Albert, R. Alfaro +82
Cosmic rays, along with stellar radiation and magnetic fields, are known to make up a significant fraction of the energy density of galaxies such as the Milky Way. When cosmic rays…
Multiwavelength follow-up of a rare IceCube neutrino multiplet
M. G. Aartsen, M. Ackermann, J. Adams +501
On February 17 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with comi…
Studies of MCP-PMTs in the miniTimeCube neutrino detector
V. A. Li, J. Koblanski, R. Dorrill +14
This report highlights two different types of cross-talk in the photodetectors of the miniTimeCube neutrino experiment. The miniTimeCube detector has 24 -anode Photonis…
HAWC Contributions to the 36th International Cosmic Ray Conference (ICRC2019)
A. U. Abeysekara, A. Albert, R. Alfaro +127
List of proceedings from the HAWC Collaboration presented at the 36th International Cosmic Ray Conference, 24 July - 1 August 2019, Madison, Wisconsin, USA.
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…
HAWC Study of the Ultra-High-Energy Spectrum of MGRO J1908+06
HAWC Collaboration, A. Albert, R. Alfaro +97
We report TeV gamma-ray observations of the ultra-high-energy source MGRO J1908+06 using data from the High Altitude Water Cherenkov (HAWC) Observatory. This source is one of the h…
Search for very-high-energy emission from Gamma-ray Bursts using the first 18 months of data from the HAWC Gamma-ray Observatory
The HAWC collaboration, R. Alfaro, C. Alvarez +102
The High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory is an extensive air shower detector operating in central Mexico, which has recently completed its first two years of…
Ultra-High-Energy Gamma-Ray Bubble around Microquasar V4641 Sgr
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez +89
Microquasars are laboratories for the study of jets of relativistic particles produced by accretion onto a spinning black hole. Microquasars are near enough to allow detailed imagi…
First HAWC Observations of the Sun Constrain Steady TeV Gamma-Ray Emission
A. Albert, R. Alfaro, C. Alvarez +92
Steady gamma-ray emission up to at least 200 GeV has been detected from the solar disk in the Fermi-LAT data, with the brightest, hardest emission occurring during solar minimum. T…
The 2HWC HAWC Observatory Gamma Ray Catalog
A. U. Abeysekara, A. Albert, R. Alfaro +108
We present the first catalog of TeV gamma-ray sources realized with the recently completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-…
Analysis of the Emission and Morphology of the Pulsar Wind Nebula Candidate HAWC J2031+415
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez +78
The first TeV gamma-ray source with no lower energy counterparts, TeV J2032+4130, was discovered by HEGRA. It appears in the third HAWC catalog as 3HWC J2031+415 and it is a bright…
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…
The TeV Sun Rises: Discovery of Gamma rays from the Quiescent Sun with HAWC
A. Albert, R. Alfaro, C. Alvarez +89
We report the first detection of a TeV gamma-ray flux from the solar disk (6.3), based on 6.1 years of data from the High Altitude Water Cherenkov (HAWC) observatory. The 0.5--…
Searching for Dark Matter Sub-structure with HAWC
A. U. Abeysekara, A. Albert, R. Alfaro +75
Simulations of dark matter show a discrepancy between the expected number of Galactic dark matter sub-halos and how many have been optically observed. Some of these unseen satellit…
Spectral study of very high energy gamma rays from SS 433 with HAWC
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez +78
Very-high-energy (0.1-100 TeV) gamma-ray emission was observed in HAWC data from the lobes of the microquasar SS 433, making them the first set of astrophysical jets that were reso…
Measurement of the Crab Nebula Spectrum Past 100 TeV with HAWC
HAWC Collaboration, A. U. Abeysekara, A. Albert +102
We present TeV gamma-ray observations of the Crab Nebula, the standard reference source in ground-based gamma-ray astronomy, using data from the High Altitude Water Cherenkov (HAWC…
High Altitude characterization of the Hunga Pressure Wave with Cosmic Rays by the HAWC Observatory
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez +64
High-energy cosmic rays that hit the Earth can be used to study large-scale atmospheric perturbations. After a first interaction in the upper parts of the atmosphere, cosmic rays p…
Long-term spectra of the blazars Mrk 421 and Mrk 501 at TeV energies seen by HAWC
A. Albert, R. Alfaro, C. Alvarez +75
The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory surveys the very high energy sky in the 300 GeV to TeV energy range. HAWC has detected two blazars above $11Ï…
A survey of active galaxies at TeV photon energies with the HAWC gamma-ray observatory
A. Albert, C. Alvarez, J. R. Angeles Camacho +86
The High Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) continuously detects TeV photons and particles within its large field-of-view, accumulating every day a deeper exposu…