R. Clavero
A5019562715- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Radiation Therapy and Dosimetry
- Galaxies: Formation, Evolution, Phenomena
- Ionosphere and magnetosphere dynamics
- Atomic and Subatomic Physics Research
- Atmospheric Ozone and Climate
- Space Exploration and Technology
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Particle physics theoretical and experimental studies
- Dialysis and Renal Disease Management
- Isotope Analysis in Ecology
- Adaptive optics and wavefront sensing
Instituto de Astrofísica de Canarias
2015-2024
Universidad de La Laguna
2015-2024
Isaac Newton Group
2010-2019
University of Maryland, College Park
2015
A precision measurement by the Alpha Magnetic Spectrometer on International Space Station of positron fraction in primary cosmic rays energy range from 0.5 to 350 GeV based $6.8\ifmmode\times\else\texttimes\fi{}{10}^{6}$ and electron events is presented. The very accurate data show that steadily increasing 10 $\ensuremath{\sim}250\text{ }\text{ }\mathrm{GeV}$, but, 20 250 GeV, slope decreases an order magnitude. spectrum shows no fine structure, ratio observable anisotropy. Together, these...
A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge dependence important understanding origin, acceleration, and propagation rays. We present detailed variation spectral index for first time. The progressively hardens at high rigidities.Received 6 March 2015DOI:https://doi.org/10.1103/PhysRevLett.114.171103This article available under terms Creative Commons Attribution 3.0...
Measurements of the positron fraction in high energy cosmic rays using space-borne Alpha Magnetic Spectrometer have been extended to energies 500 GeV. The new results show that stops increasing with at around 200
Precision measurements by the Alpha Magnetic Spectrometer on International Space Station of primary cosmic-ray electron flux in range 0.5 to 700 GeV and positron 500 are presented. The each require a description beyond single power-law spectrum. Both change their behavior at ∼30 but fluxes significantly different magnitude energy dependence. Between 20 200 spectral index is harder than index. determination differing indices versus new observation provides important information origins...
Knowledge of the precise rigidity dependence helium flux is important in understanding origin, acceleration, and propagation cosmic rays. A measurement primary rays with (momentum/charge) from 1.9 GV to 3 TV based on 50 million events presented compared proton flux. The detailed variation spectral index for first time. progressively hardens at rigidities larger than 100 GV. similar that though magnitudes are different. Remarkably, ratio increases up 45 then becomes constant; above well...
A precision measurement by AMS of the antiproton flux and antiproton-to-proton ratio in primary cosmic rays absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} events 2.42×10^{9} proton events. The fluxes ratios charged elementary particles are also presented. In ∼60 ∼500 GV, p[over ¯], p, positron e^{+} found have nearly identical dependence electron e^{-} exhibits a different dependence. Below 60 (p[over ¯]/p), ¯]/e^{+}), (p/e^{+}) each reaches maximum. From show no...
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...
Knowledge of the rigidity dependence boron to carbon flux ratio (B/C) is important in understanding propagation cosmic rays. The precise measurement B/C from 1.9 GV 2.6 TV, based on 2.3 million and 8.3 nuclei collected by AMS during first 5 years operation, presented. detailed variation with spectral index reported for time. does not show any significant structures contrast many ray models that require such at high rigidities. Remarkably, above 65 GV, well described a single power law R^{Δ}...
We report the observation of new properties primary cosmic rays He, C, and O measured in rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, 7.0×10^{6} oxygen nuclei collected by Alpha Magnetic Spectrometer (AMS) during first five years operation. Above 60 GV, these three spectra have identical dependence. They all deviate from a single power law above 200 harden an way.
We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in range 0.5 GeV to 1 TeV based on analysis 10.6 million events collected by AMS. The statistics and resolution AMS provide precision flux. is smooth reveals new distinct information. Above 30.2 GeV, can be described single power law with spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).
We report on the observation of new properties secondary cosmic rays Li, Be, and B measured in rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total 5.4×10^{6} nuclei collected by AMS during first five years operation aboard International Space Station. The Li fluxes have an identical dependence above 7 all three 30 Li/Be flux ratio 2.0±0.1. deviate from single power law 200 way. This behavior has also been observed measurement primary He, C, O but dependences are...
We present the precision measurement from May 2011 to 2017 (79 Bartels rotations) of proton fluxes at rigidities 1 60 GV and helium 1.9 based on a total 1×10^{9} events collected with Alpha Magnetic Spectrometer aboard International Space Station. This is in solar cycle 24, which has maximum April 2014. observed that, below 40 GV, flux show nearly identical fine structures both time relative amplitude. The amplitudes decrease increasing rigidity vanish above GV. are reduced during period,...
The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with significance 25.5σ using the MAGIC telescopes. Together gravitationally lensed blazar QSO B0218+357 (z 0.944), most distant very high energy (VHE) to date. observations were triggered by an outburst in 2015 April seen energies Large Area Telescope on board Fermi. Multi-wavelength suggest subdivision state into two distinct flux states. In band covered MAGIC, variability timescale...
We present high-statistics, precision measurements of the detailed time and energy dependence primary cosmic-ray electron flux positron over 79 Bartels rotations from May 2011 to 2017 in range 1 50 GeV. For first time, charge-sign dependent modulation during solar maximum has been investigated detail by leptons alone. Based on 23.5×10^{6} events, we report observation short-term structures timescale months coincident both flux. These are not visible e^{+}/e^{-} ratio. The across polarity...
A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed dependence spectral index presented for first time. rapidly hardens at high rigidities and becomes identical indices primary He, C, O cosmic rays above ∼700 GV. We observed that Φ_{N} can be as sum its component Φ_{N}^{P} secondary Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, we found well described by weighted oxygen Φ_{O} (primary rays)...
Context. QSO B0218+357 is a gravitationally lensed blazar located at redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated 10–12 day delay. In July 2014, experienced violent flare observed Fermi-LAT and followed MAGIC telescopes.
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 1 April and 10 August 2013, including first detailed characterization synchrotron peak with Swift NuSTAR. During campaign, nearby BL Lac object was observed in both a quiescent an elevated state. The campaign includes NuSTAR, MAGIC, VERITAS, Fermi Large Area Telescope (LAT), X-ray UV Optical Telescope, various ground-based optical instruments, GASP-WEBT program, as well radio by OVRO,...
Clusters of galaxies are expected to be reservoirs cosmic rays (CRs) that should produce diffuse gamma-ray emission due their hadronic interactions with the intra-cluster medium. The nearby Perseus cool-core cluster, identified as most promising target search for such an emission, has been observed MAGIC telescopes at very-high energies (VHE, E>100 GeV) a total 253 hr from 2009 2014. active nuclei NGC 1275, central dominant galaxy and IC 310, lying about 0.6$^\circ$ centre, have detected...
We study the multi-band variability and correlations of TeV blazar Mrk 421 on year time scales, which can bring additional insight processes responsible for its broadband emission. observed in very high energy (VHE) gamma-ray range with Cherenkov telescope MAGIC-I from March 2007 to June 2009 a total 96 hours effective after quality cuts. The VHE flux is quantified several methods, including Bayesian Block algorithm, applied data telescopes first time. 2.3 long MAGIC light curve complemented...
In February-March 2014, the MAGIC telescopes observed high-frequency peaked BL Lac 1ES 1011+496 (z=0.212) in flaring state at very-high energy (VHE, E>100GeV). The flux reached a level more than 10 times higher any previously recorded of source. We present description characteristics flare presenting light curve and spectral parameters night-wise spectra average spectrum whole period. From these data we aim detecting imprint Extragalactic Background Light (EBL) VHE source, order to constrain...
We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during multi-instrument campaign spanning from 2009 March 15 to August 1 which includes, among other instruments, MAGIC, VERITAS, Whipple 10-m, Fermi-LAT, RXTE, Swift, GASP-WEBT and VLBA. find increase in fractional variability with energy, while no significant interband correlations flux changes are found acquired set. The higher very high energy (>100 GeV, VHE) gamma-ray emission lack correlation X-ray...
Binary stars are invaluable tools that can be used to precisely measure the fundamental properties of stars, test stellar models, and further our understanding evolution. Stellar binarity may also play an important role in formation evolution exoplanetary systems. We provide a technique for resolving intermediate-separation binaries with medium-sized telescopes (i.e. diameter less than or equal 2.5 metres) at wavelengths around 825 nm super-resolution range below limit defined by Rayleigh...
We provide a technique for resolving intermediate-separation binaries stars with medium-sized telescopes (i.e. diameter less than or equal to 2.5 m) at wavelengths around 825 nm in the super-resolution range below limit defined by Rayleigh criterion). combined two well-known algorithms that have been applied reduce halo lucky imaging observations: COvariancE of Lucky Images (COELI) and Imaging Speckle Suppression Algorithm (LISSA). reviewed fundamentals both describe new called Super...
Very high-energy (VHE, E\,$>$\,100\,GeV) $\gamma$-ray data are a valuable input for multi-wavelength and multi-messenger (e.g. combination with neutrino data) studies. We aim at the conservation homogenization of historical, current, future {VHE $\gamma$-ray-data} on active galactic nuclei (AGN). have collected lightcurve taken by major VHE experiments since 1991 combined them into long-term lightcurves several AGN, now provide our datasets further use. Due to lack common formats in...
Context. The gamma-ray binary LS I +61°303 is a well-established source from centimeter radio up to very high energy (VHE; E> 100 GeV). broadband emission shows periodicity of ~26.5 days, coincident with the orbital period. A longer (super-orbital) period 1667 ± 8 days was proposed variability and confirmed using optical high-energy (HE; MeV) observations. In this paper, we report on four-year campaign performed by MAGIC together archival data concentrating search for long-timescale...