C. Álvarez
A5108058720- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Particle Detector Development and Performance
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Particle physics theoretical and experimental studies
- Radio Astronomy Observations and Technology
- Planetary Science and Exploration
- Radiation Detection and Scintillator Technologies
- Solar and Space Plasma Dynamics
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- Ionosphere and magnetosphere dynamics
- Spectroscopy and Laser Applications
- History and Developments in Astronomy
Autonomous University of Chiapas
2016-2025
Instituto de Investigaciones de la Amazonía Peruana
2025
Universitat Jaume I
2001-2025
W.M. Keck Observatory
2016-2024
Universidad UTE
2024
Universidad Nacional Autónoma de México
1987-2020
Case Western Reserve University
2020
Max Planck Society
2004-2018
Instituto de Astrofísica de Canarias
2008-2016
Universidad de La Laguna
2013-2016
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 analyze orbital solutions for 48 massive multiple-star systems in the Cygnus OB2 Association, 23 of which are newly presented here, to find that observed distribution periods is approximately uniform log P P<45 d, but it not scale-free. Inflections cumulative near 6 14, and 45 suggest key physical scales ~0.2, ~0.4, ~1 A.U. where yet-to-be-identified phenomena create distinct features. No single power law provides a statistically compelling prescription, if features ignored, with exponent...
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...
We report on a survey devoted to the search of exoplanets around young and nearby stars carried out with NACO at VLT. The detection limit for 28 among best available targets versus angular separation from star is presented. nondetection any planetary mass companion in our used derive, first time, frequency upper projected planet-star separation. In particular, we find that 50% cases, no 5MJ (or more massive) planet has been detected separations larger than 14 AU, 10MJ 8.5 AU. 100% these...
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...
The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic at TeV energies.The detector still under construction, but data acquisition with the partially deployed started in 2013.An analysis of cosmic-ray arrival direction distribution based on 4.9 × 10 events recorded between June 2013 February 2014 shows anisotropy -4 level angular scales about • .The HAWC sky map exhibits three regions significantly enhanced flux; two these were first reported by...
Abstract We present L ’-band imaging of the PDS 70 planetary system with Keck/NIRC2 using new infrared pyramid wave front sensor. detected both b and c in our images, as well rim circumstellar disk. After subtracting off a model disk, we measured astrometry photometry planets. Placing priors based on dynamics system, estimated to have semimajor axis <?CDATA ${20}_{-4}^{+3}$?> au ${34}_{-6}^{+12}$?> (95% credible interval). fit spectral energy distribution (SED) For b, were able place better...
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...
We present the discovery of a companion near deuterium-burning mass limit located at very wide distance, an angular separation 4.6'' ± 0.1'' (projected distance ~ 670 AU) from UScoCTIO 108, brown dwarf young Upper Scorpius association. Optical and near-infrared photometry spectroscopy confirm cool nature both objects, with spectral types M7 M9.5, respectively, that they are bona fide members association, showing low gravity features youth. Their masses, estimated comparison their bolometric...
We present Gran Telescopio CANARIAS CanariCam 8.7 μm imaging and 7.5–13 spectroscopy of six local systems known to host an active galactic nucleus (AGN) have nuclear star formation. Our main goal is investigate whether the molecules responsible for 11.3 polycyclic aromatic hydrocarbon (PAH) feature are destroyed in close vicinity AGN. detect PAH emission regions galaxies as well extended over a few hundred parsecs. The equivalent width (EW) shows minimum at but increases with increasing...
The HAWC experiment reports the first ground-based measurement of all-particle cosmic-ray spectrum in 10-500 TeV energy range. This data overlaps with direct measurements made by balloon-borne detectors as well those other higher air-shower detectors. closes an important gap between these different experiments.
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...