M. Capalbi
A5105927440- Gamma-ray bursts and supernovae
- SAS software applications and methods
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Distributed and Parallel Computing Systems
- Microbial Metabolites in Food Biotechnology
- CCD and CMOS Imaging Sensors
- Particle Accelerators and Free-Electron Lasers
- Adaptive optics and wavefront sensing
- Nuclear Physics and Applications
- Spacecraft Design and Technology
- Advanced X-ray and CT Imaging
- Spacecraft and Cryogenic Technologies
- Galaxies: Formation, Evolution, Phenomena
- Statistical and numerical algorithms
- Planetary Science and Exploration
Astronomical Observatory of Rome
2012-2023
Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo
2013-2023
Brera Astronomical Observatory
2005-2023
Agenzia Spaziale Italiana
2004-2023
Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano
2023
Osservatorio Astrofisico di Catania
2023
University of Perugia
2021-2023
National Institute for Astrophysics
2005-2022
Institute for Space Astrophysics and Planetology
2013-2022
Osservatorio Astronomico di Padova
2021
We present a homogeneous X-ray analysis of all 318 gamma-ray bursts detected by the telescope (XRT) on Swift satellite up to 2008 July 23; this represents largest sample GRB data published date. In Sections 2–3, we detail methods which Swift-XRT team has developed produce enhanced positions, light curves, hardness ratios and spectra presented in paper. Software using these continues create such products for new GRBs observed Swift-XRT. also web-based tools allowing users any object XRT, not...
(Abridged) We have conducted a detailed investigation of the broad-band spectral properties \gamma-ray selected blazars Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated gamma-ray spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray data, collected within three months LBAS data taking period, we were able to assemble high-quality quasi-simultaneous Spectral Energy Distributions (SED) for 48 blazars.The SED these sources is similar that...
We present new observations of the early X-ray afterglows first 27 gamma-ray bursts (GRBs) well observed by Swift X-Ray Telescope (XRT). The show a canonical behavior, where light curve broadly consists three distinct power-law segments: (1) an initial very steep decay (∝t-α with 3 ≲ α1 5), followed (2) shallow (0.5 α2 1.0), and finally (3) somewhat steeper (1 α3 1.5). These segments are separated two corresponding break times, tbreak,1 500 s 103 tbreak,2 104 s. On top this many events have...
Context.Swift data are revolutionising our understanding of Gamma Ray Bursts. Since bursts fade rapidly, it is desirable to create and disseminate accurate light curves rapidly.
Gamma-ray burst (GRB) afterglows have provided important clues to the nature of these massive explosive events, providing direct information on nearby environment and indirect central engine that powers burst. We report discovery two bright x-ray flares in GRB afterglows, including a giant flare comparable total energy itself, each peaking minutes after These strong, rapid imply engines bursts long periods activity, with strong internal shocks continuing for hundreds seconds gamma-ray...
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
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 simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard gamma-ray bands. Our unique set has allowed us demonstrate that selection method strongly influences results, producing biases cannot be ignored. Almost all BL Lac objects have been detected by Fermi-LAT, whereas ~40% of flat-spectrum radio quasars (FSRQs) radio, X-ray selected are still below detection limit even after integrating 27 months...
We present a comprehensive statistical analysis of Swift X-ray light curves gamma-ray bursts (GRBs) collecting data from more than 650 GRBs discovered by and other facilities. The unprecedented sample size allows us to constrain the rest-frame properties perspective, with particular reference intrinsic time-scales energetics different light-curve phases in common 0.3–30 keV energy band. Temporal variability episodes are also studied their constrained. Two fundamental questions drive this...
Long-duration Gamma-Ray Bursts (GRBs) are an extremely rare outcome of the collapse massive stars, and typically found in distant Universe. Because its intrinsic luminosity ($L\sim 3 \times 10^{53}$ erg s$^{-1}$) relative proximity ($z=0.34$), GRB 130427A was a unique event that reached highest fluence observed gamma-ray band. Here we present comprehensive multiwavelength view with Swift, 2-m Liverpool Faulkes telescopes by other ground-based facilities, highlighting evolution burst emission...
The ASTRI Mini-Array (MA) is an INAF project to build and operate a facility study astronomical sources emitting at very high-energy in the TeV spectral band. MA consists of group nine innovative Imaging Atmospheric Cherenkov telescopes. telescopes will be installed Teide Astronomical Observatory Instituto de Astrofisica Canarias (IAC) Tenerife (Canary Islands, Spain) on basis host agreement with INAF. Thanks its expected overall performance, better than those current telescopes' arrays for...
We report the best evidence to date of a jet break in short Gamma-Ray Burst (GRB) afterglow, using Chandra and Swift XRT observations X-ray afterglow GRB 051221A. The combined light curve, which has three breaks, is similar those commonly observed long GRBs. A flat segment curve at ~0.1 days after burst represents first clear case strong energy injection external shock afterglow. last occurs ~4 post-burst breaks power-law decay index ~2. interpret this as break, with important implications...
This paper discusses Swift observations of the gamma-ray burst GRB 050315 (z=1.949) from 80 s to 10 days after onset burst. The X-ray light curve displayed a steep early decay (t^-5) for ~200 and several breaks. However, both prompt hard X-ray/gamma-ray emission (observed by BAT) first ~ 300 XRT) can be explained exponential decays, with similar constants. Extrapolating BAT into XRT band suggests rapidly decaying, was simply continuation fading emission; this strong similarity between may...
Until recently, X-ray flares during the afterglow of gamma ray bursts (GRBs) were a rarely detected phenomenon, thus their nature is unclear. During GRB 050502B, largest flare ever recorded rose rapidly above lightcurve by Swift Telescope. The peak flux was >500 times that underlying afterglow, and it occurred at >12 minutes after nominal prompt burst emission. fluence this flare, (1.0 +/- 0.05) x 10^{-6} erg cm^{-2} in 0.2-10.0 keV energy band, exceeded burst. spectra significantly harder...
We have analyzed the two longest (elapsed time > 3 days) BeppoSAX observations of X-ray brightest Seyfert galaxy, NGC 4151, to search for spectral variability on time-scales from a few tens ksec years. found in both cases highly significant below ~ 6 keV down shortest investigated. These variations can be naturally explained terms low energy cut-off due obscuring matter along line sight. If is modeled by neutral absorption components, one fully covering source and second only fraction...
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...
Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) simultaneous multifrequency data. The nine frequencies, from 30 to 857 GHz, complemented by set observations ranging gamma-rays. This is first extensive frequency coverage in millimetre domains an essentially complete it shows how individual shocks, each their own phase development, shape as they...
Blazars research is one of the hot topics contemporary extra-galactic astrophysics. That because these sources are most abundant type gamma-ray and suspected to play a central role in multi-messenger We have used swift_xrtproc, tool carry out an accurate spectral photometric analysis Swift-XRT data all blazars observed by Swift at least 50 times between December 2004 end 2020. present database X-ray spectra, best-fit parameter values, count-rates flux estimations several energy bands over...
We present optical and near-infrared observations of the afterglow gamma-ray burst GRB 050904. derive a photometric redshift z = 6.3, estimated from presence Lyman break falling between I J filters. This is by far most distant known to date. Its isotropic-equivalent energy 3.4x10^53 erg in rest-frame 110-1100 keV band. Despite high redshift, both prompt emission are not peculiar with respect other GRBs. find J-band light curve at t_b 2.6 +- 1.0 d (observer frame). If we assume this jet...
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,...
We present the results of a series Swift and quasi simultaneous ground-based infra-red observations blazar 3C 454.3 carried out in April-May 2005 when source was 10 to 30 times brighter than previously observed. found be very bright variable at all frequencies covered by our instrumentation. The broad-band Spectral Energy Distribution (SED) shows usual two-bump shape (in nu-nu f(nu) space) with Infra-red, optical UV data sampling declining part synchrotron emission that, even during this...
The Swift Gamma Ray Burst satellite routinely provides prompt positions for GRBs and their afterglows on timescales of a few hundred seconds. However, with pointing accuracy only arcminutes, systematic uncertainty the star-tracker solutions to World Coordinate System 3–4 arcsec, precision early XRT is limited arcsec at best. This significant because operationally, detects >95% all GRBs, while UVOT optically brightest bursts, ~30% bursts detected by BAT; thus accurate are important majority...