R. Paoletti
A5027349658- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Radiation Detection and Scintillator Technologies
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- Astronomy and Astrophysical Research
- Medical Imaging Techniques and Applications
- Computational Physics and Python Applications
- Gyrotron and Vacuum Electronics Research
- Advanced X-ray and CT Imaging
- Terahertz technology and applications
- Adaptive optics and wavefront sensing
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
University of Siena
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2015-2024
Universitat de Barcelona
2021-2024
Instituto de Astrofísica de Canarias
2021-2024
Universidad de La Laguna
2021-2024
Institut d'Estudis Espacials de Catalunya
2024
Universidad Complutense de Madrid
2006-2023
The University of Tokyo
2021-2023
Max Planck Institute for Physics
2021-2023
Czech Academy of Sciences, Institute of Physics
2023
The blazar Mrk 501 was observed at energies above 0.10 TeV with the MAGIC Telescope from 2005 May through July. high sensitivity of instrument enabled determination flux and spectrum source on a night-by-night basis. Throughout our observational campaign, found to vary by an order magnitude. Intranight variability flux-doubling times down 2 minutes during two most active nights, namely, June 30 July 9. These are fastest variations ever in 501. ~20 minute long flare 9 showed indication 4 ± 1...
The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at distance more than 5 billion light-years (a redshift 0.536). No quasar been observed previously in radiation, and this is also most object emitting above 50 gigaelectron volts. Because high-energy may be stopped by interacting with diffuse background light universe,...
Microquasars are binary star systems with relativistic radio-emitting jets. They potential sources of cosmic rays and can be used to elucidate the physics We report detection variable gamma-ray emission above 100 gigaelectron volts from microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar phase, which suggests that is periodic. The strongest not observed when two stars closest one another, implying strong modulation or absorption processes.
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 report about very high energy (VHE) γ-ray observations of the Crab Nebula with MAGIC telescope. The flux from nebula was measured between 60 GeV and 9 TeV. spectrum can be described by a curved power law dF/dE = f0(E/300 GeV)[a+blog10(E/300 GeV)] normalization f0 (6.0 ± 0.2stat) × 10−10 cm−2 s−1 TeV−1, − 2.31 0.06stat, b 0.26 0.07stat. peak in spectral distribution is estimated at 77 35 GeV. Within observation time experimental resolution telescope, emission steady pointlike. emission's...
We analyze the timing of photons observed by MAGIC telescope during a flare active galactic nucleus Mkn 501 for possible correlation with energy, as suggested some models quantum gravity (QG), which predict vacuum refractive index ≃1+(E/MQGn)n, n=1,2. Parametrizing delay between γ-rays different energies Δt=±τlE or Δt=±τqE2, we find τl=(0.030±0.012) s/GeV at 2.5-σ level, and τq=(3.71±2.57)×10−6 s/GeV2, respectively. use these results to establish lower limits MQG1>0.21×1018 GeV...
The TOTEM Experiment will measure the total pp cross-section with luminosity-independent method and study elastic diffractive scattering at LHC. To achieve optimum forward coverage for charged particles emitted by collisions in interaction point IP5, two tracking telescopes, T1 T2, be installed on each side pseudorapidity region 3.1 ⩽ |η| 6.5, Roman Pot stations placed distances of ±147 m ±220 from IP5. Being an independent experiment but technically integrated into CMS, first operate...
We report on the results from observations in very high energy band (VHE; Eγ ≥ 100 GeV) of black hole X-ray binary (BHXB) Cygnus X-1. The were performed with MAGIC telescope, for a total 40 hr during 26 nights, spanning period between 2006 June and November. Searches steady γ-ray signals yielded no positive result, upper limits to integral flux ranging 1% 2% Crab Nebula flux, depending energy, have been established. also analyzed each observation night independently, obtaining evidence at...
One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring high-end region a pulsar's spectrum would shed light on this question. By developing new electronic trigger, we lowered threshold Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 GeV. In configuration, detected gamma-rays from Crab pulsar that were greater than GeV, revealing relatively high cutoff energy in phase-averaged spectrum. This indicates emission...
We report the detection of a new source very high energy (VHE; Eγ ≥ 100 GeV) γ-ray emission located close to Galactic plane, MAGIC J0616+225, which is spatially coincident with supernova remnant IC 443. The observations were carried out telescope in periods 2005 December-2006 January and 2006 December-2007 January. Here we present results from this source, leading VHE signal statistical significance 5.7 σ 2006/2007 data measured differential flux consistent power law, described as dNγ/(dA dt...
Recently, the Galactic center has been reported to be a source of very high energy (VHE) γ-rays by CANGAROO, VERITAS, and HESS experiments. The spectra as measured these experiments show substantial differences. In this Letter we present MAGIC observations center, resulting in detection differential γ-ray flux consistent with steady, hard-slope power law, described dNγ/(dA dt dE) = (2.9 ± 0.6) × 10-12(E/TeV)-2.2±0.2 cm-2 s-1 TeV-1. is centered at (R.A., decl.) (17h45m20s, -29°2'). This...
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%...
The MAGIC telescope took data of very high energy gamma-ray emission from the blazar Markarian 421 (Mkn 421) between November 2004 and April 2005. We present a combined analysis samples recorded under different observational conditions, down to energies 100 GeV. flux was found vary 0.5 -- 2 Crab units (integrated above 200 GeV), considered low state when compared known data. Although varied on day-by-day basis, no short-term variability observed, although there is some indication that not...
The MAGIC collaboration observed BL Lacertae for 22.2 hr during 2005 August to December and 26 2006 July September. source is the historical prototype eponym of a class low-frequency-peaked (LBL) objects. A very high energy (VHE) γ-ray signal was discovered with 5.1 σ excess in data. Above 200 GeV, an integral flux (0.6 ± 0.2) × 10-11 cm-2 s-1 measured, corresponding approximately 3% Crab flux. differential spectrum between 150 900 GeV rather steep photon index -3.6 0.5. light curve shows no...
We report the results of observation nearby satellite galaxy Segue 1 performed by MAGIC-I ground-based gamma-ray telescope between November 2008 and March 2009 for a total 43.2 hours. No significant emission was found above background. Differential upper limits on flux are derived assuming various power-law slopes possible spectrum. Integral also calculated several spectra different energy thresholds. The values order 10^{-11} ph cm^{-2}$ s^{-1} 100 GeV 10^{-12} cm^{-2} 200 GeV. is currently...
We searched for very high energy (VHE) gamma-ray emission from the supernova remnant Cassiopeia A. The shell-type A was observed with 17 meter MAGIC telescope between July 2006 and January 2007 a total time of 47 hours. source detected above an 250 GeV significance 5.2sigma photon flux 1 TeV (7.3+-0.7_stat+-2.2_sys)10^-13 cm^-2s^-1. spectrum is compatible power law dN/dE = E^-Gamma index Gamma=2.3+-0.2_stat+-0.2_sys. point-like within angular resolution telescope.
We report on the detection of very-high energy (VHE, E > 100 GeV) γ-ray emission from NGC 1275, central radio galaxy Perseus cluster galaxies. The source has been detected by MAGIC telescopes with a statistical significance 6.6σ above GeV in 46 h stereo observations carried out between August 2010 and February 2011. measured differential spectrum 70 500 can be described power law steep spectral index Γ = −4.1 ± 0.7stat 0.3syst, average flux is Fγ (1.3 0.2stat 0.3syst) × 10-11 cm-2 s-1. These...
The MAGIC collaboration has recently reported the discovery of γ-ray emission from binary system LS I +61°303 in TeV energy region. Here we present new observational results on this source range between 300 GeV and 3 TeV. In total, 112 hr data were taken 2006 September December covering four orbital cycles object. This large amount allowed us to produce an integral flux light curve for first time all phases +61°303. addition, also obtained a differential spectrum two phase bins 0.5 < ϕ 0.6...
We report on the observation of $\gamma$-rays above 25\,GeV from Crab pulsar (PSR B0532+21) using MAGIC I telescope. Two data sets observations during winter period 2007/2008 and 2008/2009 are used. In order to discuss spectral shape 100\,MeV 100\,GeV, one year public {\it Fermi} Large Area Telescope ({\it Fermi}-LAT) also analyzed complement data. The extrapolation exponential cutoff spectrum determined with Fermi-LAT is inconsistent measurements, which requires a modification standard...
We use 73 h of stereoscopic data taken with the MAGIC telescopes to investigate very high-energy (VHE) gamma-ray emission Crab pulsar. Our show a highly significant pulsed signal in energy range from 50 400 GeV both main pulse (P1) and interpulse (P2) phase regions. provide widest spectra date VHE components peaks, these extend satellite-borne observatories. The good resolution background rejection system allows us cross-check correctness each spectral point pulsar by comparison...
Aims. We aim to characterize the multiwavelength emission from Markarian 501 (Mrk 501), quantify energy-dependent variability, study potential multiband correlations, and describe temporal evolution of broadband within leptonic theoretical scenarios. Methods. organized a campaign take place between March July 2012. Excellent coverage was obtained with more than 25 instruments, including MAGIC, FACT VERITAS Cherenkov telescopes, instruments on board Swift Fermi spacecraft, telescopes operated...