T. Capistrán
A5010199371- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Radiation Detection and Scintillator Technologies
- Astrophysical Phenomena and Observations
- Particle Accelerators and Free-Electron Lasers
- Solar and Space Plasma Dynamics
- Cosmology and Gravitation Theories
- Radiation Therapy and Dosimetry
- Ionosphere and magnetosphere dynamics
- Computational Physics and Python Applications
- Particle accelerators and beam dynamics
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Atomic and Subatomic Physics Research
- Atmospheric Ozone and Climate
- Quantum Mechanics and Applications
- Black Holes and Theoretical Physics
- Neuroblastoma Research and Treatments
University of Turin
2025
Universidad Nacional Autónoma de México
2021-2024
National Institute of Astrophysics, Optics and Electronics
2016-2021
University of California, Santa Cruz
2021
University of Maryland, College Park
2021
Michigan State University
2021
Education University of Hong Kong
2021
University of Hong Kong
2021
University of Chile
2020
Max Planck Society
2018
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...
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.
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 The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field of view sensitive to 500 GeV–100 TeV gamma-rays and cosmic rays. It can also perform diverse indirect searches for dark matter annihilation decay. Among the most promising targets detection are dwarf spheroidal galaxies. These objects expected have few astrophysical sources but high content, making them ideal candidates an with gamma-rays. Here we present individual limits on cross section decay lifetime...
Abstract The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, located on the side of Sierra Negra volcano in Mexico, has been fully operational since 2015. HAWC collaboration recently significantly improved their extensive air shower reconstruction algorithms, which notably advanced observatory performance. energy resolution for primary gamma rays with energies below 1 TeV was by including a noise-suppression algorithm. Corrections have also made to systematic errors direction...
Abstract Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons, and electrons, interacting with gas electromagnetic radiation fields in the interstellar medium. Here we present analysis of teraelectronvolt from a region plane over range longitude l ∈ [43°, 73°], using data collected High Altitude Water Cherenkov (HAWC) detector. Spectral, longitudinal, latitudinal distributions are shown. The spectrum compatible arising CR population an index...
Abstract We present the first full-sky analysis of cosmic ray arrival direction distribution with data collected by High-Altitude Water Cherenkov and IceCube observatories in northern southern hemispheres at same median primary particle energy 10 TeV. The combined sky map angular power spectrum largely eliminate biases that result from partial coverage a key to probe into propagation properties TeV rays through our local interstellar medium interaction between heliospheric magnetic fields....
Abstract We present the detection of very-high-energy gamma-ray emission above 100 TeV from HAWC J2227+610 with High-Altitude Water Cherenov Gamma-Ray Observatory (HAWC) observatory. Combining our observations previously published results by Very Energetic Radiation Imaging Telescope Array System (VERTIAS), we interpret as protons a lower limit in their cutoff energy 800 TeV. The most likely source is associated supernova remnant G106.3+2.7, making it good candidate for Galactic PeVatron....
Because of the high energies and long distances to sources, astrophysical observations provide a unique opportunity test possible signatures Lorentz invariance violation (LIV). Superluminal LIV enables decay photons at energy. The altitude water Cherenkov (HAWC) observatory is among most sensitive gamma-ray instruments currently operating above 10 TeV. HAWC finds evidence 100 TeV photon emission from least four sources. These exclude, for strongest limits set, energy scale 2.2×10^{31} eV,...
We analyze the Sun as a source for indirect detection of dark matter through search gamma rays from solar disk. Capture by elastic interactions with nuclei followed annihilation to long-lived mediators can produce detectable gamma-ray flux. three years data High Altitude Water Cherenkov Observatory and find no statistically significant TeV emission Sun. Using this, we constrain spin-dependent scattering cross section protons masses above 1 TeV, assuming an unstable mediator favorable...
Abstract The Earth is bombarded by ultrarelativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=10 15 eV), the knee in particle spectrum, are believed have Galactic origin. One or more factories of CRs, PeVatrons, must thus be active within our Galaxy. direct detection protons from their sources not possible since they deflected magnetic fields. Hundred TeV γ -rays decaying π 0 , produced when collide ambient gas, can provide decisive evidence proton...
We report the first detection of a TeV γ-ray flux from solar disk (6.3σ), based on 6.1 years data High Altitude Water Cherenkov (HAWC) observatory. The 0.5–2.6 spectrum is well fit by power law, dN/dE=A(E/1 TeV)−γ, with A=(1.6±0.3)×10−12 TeV−1 cm−2 s−1 and γ=3.62±0.14. shows strong indication anticorrelation activity. These results extend bright, hard GeV emission observed Fermi-LAT, seemingly due to hadronic Galactic cosmic rays showering nuclei in atmosphere. However, current theoretical...
We present results from daily monitoring of gamma rays in the energy range $\sim0.5$ to $\sim100$ TeV with first 17 months data High Altitude Water Cherenkov (HAWC) Observatory. Its wide field view 2 steradians and duty cycle $>95$% are unique features compared other observatories that allow us observe every source transits over HAWC for up $\sim6$ hours each sidereal day. This regular sampling yields unprecedented light curves unbiased measurements independent seasons or weather conditions....
Abstract The highest-energy known gamma-ray sources are all located within 0.°5 of extremely powerful pulsars. This raises the question whether ultra-high-energy (UHE; >56 TeV) emission is a universal feature expected near pulsars with high spin-down power. Using four years data from High Altitude Water Cherenkov Gamma-Ray Observatory, we present joint-likelihood analysis 10 to search for subthreshold UHE correlated these locations. We report significant detection (>3 σ ), indicating...
A measurement with high statistics of the differential energy spectrum light elements in cosmic rays, particular, primary H plus He nuclei, is reported. The presented range from $6$ to $158$ TeV per nucleus. Data was collected High Altitude Water Cherenkov (HAWC) Observatory between June 2015 and 2019. analysis based on a Bayesian unfolding procedure, which applied subsample vertical HAWC data that enriched $82\%$ events induced by nuclei. To achieve mass separation, cut lateral age air...
Abstract We present a new catalog of TeV gamma-ray sources using 1523 days data from the High-Altitude Water Cherenkov (HAWC) Observatory. The represents most sensitive survey northern sky at energies above several TeV, with three times exposure compared to previous HAWC catalog, 2HWC. report 65 detected ≥5 σ significance, along positions and spectral fits for each source. contains eight that have no counterpart in 2HWC but are within 1° previously emitters, 20 more than away any Of these...
Abstract Extended very-high-energy (VHE; 0.1–100 TeV) γ -ray emission has been observed around several middle-aged pulsars and referred to as “TeV halos.” Their formation mechanism remains under debate. It is also unknown whether they are ubiquitous or related a certain subgroup of pulsars. With 2321 days observation, the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory detected VHE at location radio-quiet pulsar PSR J0359+5414 with >6 σ significance. By performing likelihood...
We present a search of very high energy gamma-ray emission from the Northern $\textit{Fermi}$ Bubble region using data collected with High Altitude Water Cherenkov (HAWC) observatory. The size set is 290 days. No significant excess observed in region, hence upper limits above $1\,\text{TeV}$ are calculated. between $3\times 10^{-7}\,\text{GeV}\, \text{cm}^{-2}\, \text{s}^{-1}\,\text{sr}^{-1}$ and $4\times 10^{-8}\,\text{GeV}\,\text{cm}^{-2}\,\text{s}^{-1}\,\text{sr}^{-1}$. disfavor proton...
A survey of the inner Galaxy region Galactic longitude l in [+15, +50] degree and latitude b [-4,+4] is performed using one-third High Altitude Water Cherenkov (HAWC) Observatory operated during its construction phase. To address ambiguities arising from unresolved sources data, we use a maximum likelihood technique to identify point source candidates. Ten candidate are identified this analysis. Eight these associated with known TeV but not all have differential fluxes compatible previous...