J. Becerra González
A5100642523- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Particle Accelerators and Free-Electron Lasers
- Astronomical Observations and Instrumentation
- Particle physics theoretical and experimental studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Solar and Space Plasma Dynamics
- Gyrotron and Vacuum Electronics Research
- Radiation Detection and Scintillator Technologies
- Stellar, planetary, and galactic studies
- Calibration and Measurement Techniques
- Noncommutative and Quantum Gravity Theories
- Geophysics and Gravity Measurements
- Particle accelerators and beam dynamics
- Advanced X-ray and CT Imaging
- Radiation Therapy and Dosimetry
- Nuclear Physics and Applications
Instituto de Astrofísica de Canarias
2015-2024
Universidad de La Laguna
2015-2024
Universitat de Barcelona
2021-2024
Institut d'Estudis Espacials de Catalunya
2024
Turku Centre for Computer Science
2019-2023
University of Turku
2016-2023
Universidad Complutense de Madrid
2001-2023
Inter-University Centre for Astronomy and Astrophysics
2023
National and Kapodistrian University of Athens
2023
Campbell Collaboration
2023
We present the fourth Fermi Large Area Telescope catalog (4FGL) of gamma-ray sources. Based on first eight years science data from Gamma-ray Space mission in energy range 50 MeV to 1 TeV, it is deepest yet this range. Relative 3FGL catalog, 4FGL has twice as much exposure well a number analysis improvements, including an updated model for Galactic diffuse emission, and two sets light curves (1-year 2-month intervals). The includes 5064 sources above 4 sigma significance, which we provide...
The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It based on (3FGL) sources between 100 MeV and 300 GeV with a Test Statistic (TS) greater than 25, 2008 August 4 2012 July 31. 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\deg}), 71% increase over second 2 years data. There are 28 duplicate associations, thus 1563 2192 high-latitude gamma-ray 3FGL AGNs. Most them (98%) blazars. About half newly blazars unknown type, i.e.,...
We present the first joint analysis of gamma-ray data from MAGIC Cherenkov telescopes and Fermi Large Area Telescope (LAT) to search for signals dark matter annihilation in dwarf satellite galaxies. combine 158 hours Segue 1 observations with 6-year 15 galaxies by -LAT. obtain limits on cross-section particle masses between 10 GeV 100 TeV—the widest mass range ever explored a single analysis. These improve previously published -LAT results up factor two at certain masses. Our new inclusive...
Very high energy (VHE) γ-ray emission from the flat spectrum radio quasar (FSRQ) PKS 1222+21 (4C 21.35, z = 0.432) was detected with MAGIC Cherenkov telescopes during a short observation (∼0.5 hr) performed on 2010 June 17. The detection coincides high-energy MeV/GeV activity measured by Large Area Telescope (LAT) board Fermi satellite. VHE extends about 70 GeV up to at least 400 and can be well described power-law dN/dE ∝ E−Γ photon index Γ 3.75 ± 0.27stat 0.2syst. averaged integral flux...
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 fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area (4LAC) between 2008 August 4 and 2016 2 contains 2863 objects located at high Galactic latitudes (|b|>10{\deg}). It includes 85% more sources than previous 3LAC based on years data. AGNs represent least 79% high-latitude in Fermi-Large Source Catalog (4FGL), which covers energy range from 50 MeV to 1 TeV. In addition, 344 gamma-ray are found low latitudes. Most 4LAC blazars (98%),...
We present a catalog of sources detected above 50 GeV by the {\it Fermi}-Large Area Telescope (LAT) in 80 months data. The newly delivered Pass 8 event-level analysis allows detection and characterization GeV--2 TeV energy range. In this band, Fermi}-LAT has 360 sources, which constitute second hard (2FHL). improved angular resolution enables precise localization point ($\sim$1.7$'$ radius at 68 % C.~L.) spatially extended sources. find that 86 can be associated with counterparts other...
On 2015 June 16, Fermi-LAT observed a giant outburst from the flat spectrum radio quasar 3C 279 with peak $>100$ MeV flux of $\sim3.6\times10^{-5}\;{\rm photons}\;{\rm cm}^{-2}\;{\rm s}^{-1}$ averaged over orbital period intervals. It is historically highest $\gamma$-ray source including past EGRET observations, isotropic luminosity reaching $\sim10^{49}\;{\rm erg}\;{\rm s}^{-1}$. During outburst, Fermi spacecraft, which has an 95.4 min, was operated in special pointing mode to optimize...
We report for the first time a gamma-ray and multi-wavelength nearly-periodic oscillation in an active galactic nucleus. Using Fermi Large Area Telescope (LAT) we have discovered apparent quasi-periodicity flux (E >100 MeV) from GeV/TeV BL Lac object PG 1553+113. The marginal significance of 2.18 +/-0.08 year-period cycle is strengthened by correlated oscillations observed radio optical fluxes, through data collected OVRO, Tuorla, KAIT, CSS monitoring programs Swift UVOT. appearing ~10 years...
Abstract A neutrino with energy ∼290 TeV, IceCube-170922A, was detected in coincidence the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, chance being rejected at ∼3 σ level. We monitored very-high-energy (VHE) band Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes for ∼41 hr from 1.3 to 40.4 days after detection. Day-timescale variability is clearly resolved. interpret quasi-simultaneous and broadband electromagnetic observations a novel one-zone...
Abstract We report the discovery of GRB 221009A, highest flux gamma-ray burst (GRB) ever observed by Fermi Gamma-ray Burst Monitor (Fermi-GBM). This has continuous prompt emission lasting more than 600 s, which smoothly transitions to afterglow visible in Fermi-GBM energy range (8 keV–40 MeV), and total energetics higher any other sample. By using a variety new existing analysis techniques we probe spectral temporal evolution 221009A. find no prior trigger time ( t 0 ; 2022 October 9 at...
Abstract We present 294 pulsars found in GeV data from the Large Area Telescope (LAT) on Fermi Gamma-ray Space Telescope. Another 33 millisecond (MSPs) discovered deep radio searches of LAT sources will likely reveal pulsations once phase-connected rotation ephemerides are achieved. A further dozen optical and/or X-ray binary systems colocated with also harbor gamma-ray MSPs. This catalog thus reports roughly 340 and candidates, 10% all known pulsars, compared to ≤11 before Fermi. Half...
The Fermi Large Area Telescope (LAT) light curve repository (LCR) is a publicly available, continually updated library of gamma-ray curves variable Fermi-LAT sources generated over multiple timescales. LCR aims to provide publication-quality binned on timescales 3 days, 7 and 30 days for 1525 deemed in the source catalog first 10 years observations. consists through full likelihood analyses that model surrounding region, providing fluxes photon indices each time bin. intended as resource...
Abstract We present results from a high-cadence multiwavelength observational campaign of the enigmatic changing-look active galactic nucleus 1ES 1927+654 2022 May to 2024 April, coincident with an unprecedented radio flare (an increase in flux by factor ∼60 over few months) and emergence spatially resolved jet at 0.1–0.3 pc scales. Companion work has also detected recurrent quasi-periodic oscillation (QPO) 2–10 keV band increasing frequency (1–2 mHz) same period. During this time, soft...
Supermassive black holes with masses of millions to billions solar are commonly found in the centers galaxies. Astronomers seek image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method resolve small structures is measure time variability their emission. Here, we report on gamma-ray observations galaxy IC 310 obtained MAGIC telescopes revealing doubling scales faster than 4.8 min. Causality constrains size emission region be...
Gamma rays reveal the Universe's history How many stars have formed in Universe, and when did they do so? These fundamental questions are difficult to answer because there systematic uncertainties converting light we observe into total mass of galaxies. The Fermi-LAT Collaboration addressed these by exploiting way that gamma from distant blazars propagate through intergalactic space, which depends on amount emitted all collaboration found star formation peaked about 3 billion years after Big...
The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hr during 2008 November and December. resulting upper limits on gamma-ray emission above 100 GeV are in range 4.6 to 7.5 x 10^{-12} cm^{-2} s^{-1} spectral indices from -1.5 -2.5, thereby constraining produced cosmic rays, dark matter annihilations, central radio NGC1275. Results compatible with cosmological simulations cosmic-ray-induced emission, average ray-to-thermal pressure <4%...
We present the fourth Fermi Large Area Telescope catalog (4FGL) of gamma-ray sources. Based on first eight years science data from Gamma-ray Space mission in energy range 50 MeV to 1 TeV, it is deepest yet this range. Relative 3FGL catalog, 4FGL has twice as much exposure well a number analysis improvements, including an updated model for Galactic diffuse emission, and two sets light curves (1-year 2-month intervals). The includes 5064 sources above 4 sigma significance, which we provide...
We present the results of stereoscopic observations satellite galaxy Segue 1 with MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours good-quality data, this is deepest observational campaign on any dwarf performed so far in very high energy range electromagnetic spectrum. search large data sample for signals dark matter particles mass 100 GeV 20 TeV. For we use full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral...