A5010599772- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- SAS software applications and methods
- Astronomy and Astrophysical Research
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- High-pressure geophysics and materials
- Geophysics and Gravity Measurements
- Superconducting and THz Device Technology
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Calibration and Measurement Techniques
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Solar and Space Plasma Dynamics
- Radiation Therapy and Dosimetry
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- Galaxies: Formation, Evolution, Phenomena
- Neutrino Physics Research
Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo
2015-2024
Brera Astronomical Observatory
2007-2023
University of Perugia
2023
Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano
1994-2023
Osservatorio Astrofisico di Catania
2023
Osservatorio Astronomico di Padova
2023
National Institute for Astrophysics
2013-2022
University of Liverpool
2022
CTA Observatory
2021
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2020
The scientific instrumentation on board the X-ray Astronomy Satellite BeppoSAX includes a Medium Energy Concentrator Spectrometer (MECS), operating in energy range keV, which consists of three units, each composed grazing incidence Mirror Unit and position sensitive Gas Scintillation Proportional Counter. design performance MECS instrument are here described, together with its on-ground calibration.
We present the first systematic investigation of morphological and timing properties flares in GRBs observed by Swift XRT. consider a large sample drawn from all detected Swift, INTEGRAL, HETE-2 prior to 2006 January 31, which had an XRT follow-up showed significant flaring. Our 33 includes long short, at low high redshift, total 69 flares. The strongest occur early phases, with clear anticorrelation between flare peak intensity time occurrence. Fitting each X-ray Gaussian model, we find...
We present observations of GRB 060124, the first event for which both prompt and afterglow emission could be observed simultaneously in their entirety by three Swift instruments. Indeed, Swift-BAT triggered on a precursor ~570s before main burst peak, this allowed to repoint narrow field instruments position ~350s occurred. 060124 also Konus-Wind, harder gamma-ray band (up 2MeV). Thanks these exceptional circumstances, temporal spectral properties can studied optical, X-ray ranges. While...
We present a detailed analysis of Swift multi-wavelength observations GRB 070110 and its remarkable afterglow. The early X-ray light curve, interpreted as the tail prompt emission, displays spectral evolution already seen in other gamma-ray bursts. optical afterglow shows shallow decay up to ~2 d after burst, which is not consistent with standard models. most intriguing feature very steep flux at ~20 ks ending an apparent plateau. abrupt drop curve rules out external shock origin plateau...
GRB 060614 is a remarkable gamma-ray burst (GRB) observed by Swift with puzzling properties, which challenge current progenitor models. In particular, the lack of any bright supernova (SN) down to very strict limits and vanishing spectral lags during whole are typical short GRBs, strikingly at odds long (102 s) duration this event. Here we present detailed temporal analysis observations 060614. We show that presents standard optical, ultraviolet X-ray afterglows, detected beginning 4 ks...
<i>Context. <i/>Highly magnetized pulsars accreting matter in a binary system are bright sources the X-ray band (0.1–100 keV). Despite early comprehension of basic emission mechanism, their spectral energy distribution is generally described by phenomenological or simplified models.<i>Aims. <i/>We propose study from high mass pulsar 4U 0115+63 means thermal and bulk Comptonization models based on physical properties such objects.<i>Methods. <i/>For this purpose, we analyze <i>BeppoSAX<i/>...
We present the Palermo Swift-BAT hard X-ray catalogue obtained from analysis of data relative to first 39 months Swift mission. have developed a dedicated software perform reduction, mosaicking and source detection on BAT survey data. analyzed dataset in three energy bands (14-150 keV, 14-30 14-70 keV), obtaining list 962 detections above significance threshold 4.8 standard deviations. The identification counterparts was pursued using strategies: cross-correlation with published catalogues,...
The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from very earliest phases of burst. X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after burst, indicative jet break. This break time combined total energy constrains opening angle to be 3.2 degrees. We derive an empirical `time-lag' redshift BAT data z_hat = 0.69 +/- 0.02, in good agreement spectroscopic 0.61. Prior break,...
<i>Aims. <i/>We develop a code, the BatImager, for efficient data processing and image reconstruction of <i>Swift<i/>-BAT survey data. <i>Methods. <i/>The software performs via cross-correlation method also generates source spectra light curves. The is optimized direct production all-sky mosaics on an equi-area spherical grid. To reduce systematic errors, we perform accurate inflight calibration instrument, producing improved description mask pattern, time-dependent pixel equalization maps,...
We report on the first detection of very high-energy (VHE) gamma-ray emission from Crab Nebula by a Cherenkov telescope in dual-mirror Schwarzschild-Couder (SC) configuration. The result has been achieved means 4 m size ASTRI-Horn telescope, operated Mt. Etna (Italy) and developed context Telescope Array Observatory preparatory phase. SC design is aplanatic characterized small plate scale, allowing us to implement large field view cameras with small-size pixel sensors high compactness....
Context. Our knowledge of the intrinsic properties short duration Gamma-Ray Bursts has relied, so far, only upon a few cases for which estimate distance and an extended, multiwavelength monitoring afterglow have been obtained.
Short duration (2 s) Gamma-ray bursts (GRBs) have been a mystery since their discovery. Until May 2005 very little was known about short GRBs, but this situation has changed rapidly in the last few months Swift and HETE-2 satellites made it possible to discover X-ray optical counterparts these sources. Positional associations indicate that GRBs arise close-by galaxies (). Here we report on detailed study of GRB 050724 afterglow. This burst shows strong flaring variability band. It clearly...
Using gamma-ray data collected by the Astro-rivelatore Gamma ad Immagini LEggero (AGILE) satellite over a period of almost one year (from 2007 July to 2008 June), we searched for pulsed signals from 35 potentially interesting radio pulsars, ordered according and which contemporary or recent were available. AGILE detected three new top-ranking nearby Vela-like pulsars with good confidence both through timing spatial analysis. Among newcomers find very high rotational energy losses, such as...
The robotic ROTSE-III telescope network detected prompt optical emission contemporaneous with the gamma-ray of Swift events GRB051109A and GRB051111. Both datasets have continuous coverage at high signal-to-noise levels from phase onwards, thus early observations are readily compared to XRT BAT energy detections. In both cases, afterglow is established, declining steadily during emission. For GRB051111, there evidence an excess component consistent flux spectrally extrapolated gamma-rays,...
The Athena+ mission concept is designed to implement the Hot and Energetic Universe science theme submitted European Space Agency in response call for White Papers definition of L2 L3 missions its program. payload consists a large aperture high angular resolution X-ray optics twelve meters away, two interchangeable focal plane instruments: Integral Field Unit (X-IFU) Wide Imager (WFI). X-IFU cryogenic spectrometer, based on array Transition Edge Sensors (TES), offering 2.5 eV spectral...
In this paper, the development of dual mirror Small Size Telescopes (SST) for Cherenkov Telescope Array (CTA) is reviewed. Up to 70 SST, with a primary diameter 4 m, will be produced and installed at CTA southern site. These allow investigation gamma-ray sky highest energies accessible CTA, in range from about 1 TeV 300 TeV. The telescope presented contribution characterized by two major innovations: use Schwarzschild-Couder configuration an innovative camera using as sensors either...
The Cherenkov Telescope Array (CTA) foresees, in its southern site (Chile), the implementation of up to 70 small-sized telescopes (SSTs), which will extend energy coverage hundreds TeV. It has been proposed that one first set CTA SSTs be represented by ASTRI mini-array, includes (at least) nine telescopes. endto-end prototype such telescopes, named SST-2M, is installed Italy and it now completing overall commissioning entering science verification phase. are characterized an optical system...
Long gamma-ray bursts (GRBs) are bright flashes of high-energy photons that can last for tens minutes; they generally associated with galaxies have a high rate star formation and probably arise from the collapsing cores massive stars, which produce highly relativistic jets (collapsar model). Here we describe gamma- X-ray observations most distant GRB ever observed (GRB 050904): its redshift (z) 6.29 means this explosion happened 12.8 billion years ago, corresponding to time when Universe was...
Swift discovered the high redshift GRB 050319 with Burst Alert Telescope and began observing its narrow field instruments only 225 s after burst onset. The afterglow X-ray emission was monitored by XRT up to 28 days burst. light curve shows a decay three different phases, each characterized distinct slope: an initial steep power law index of ~ 5.5, second phase flat slope \~ 0.54, third 1.14. During first spectral energy distribution is softer than in following two phases photon consistent...
We present a catalogue of refined positions 68 gamma ray burst (GRB) afterglows observed by the Swift X-ray Telescope (XRT) from launch up to 2005 Oct 16. This is result refinement XRT boresight calibration. tested this correction means systematic study large sample sources with well established optical counterparts. found that we can reduce error radius measurements factor two, 6.5" 3.2" (90% confidence). corrected all in first 11 months mission. particularly important for 37 without...
The Swift X-ray Telescope (XRT) is designed to make astrometric, spectroscopic and photometric observations of the emission from Gamma-ray bursts their afterglows, in energy band 0.2-10 keV. was successfully launched on 2004 November 20. Here we report results analysis XRT Point Spread Function (PSF) as measured first four months mission during instrument calibration phase. includes study PSF different point-like sources both on-axis off-axis with spectral properties. We compare in-flight...