A. Melandri
A5003136954- Gamma-ray bursts and supernovae
- SAS software applications and methods
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Spectroscopy and Chemometric Analyses
- Adaptive optics and wavefront sensing
- Particle Detector Development and Performance
- Inertial Sensor and Navigation
- Solar and Space Plasma Dynamics
- Statistical and numerical algorithms
- Methane Hydrates and Related Phenomena
- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Planetary Science and Exploration
- Medical Imaging Techniques and Applications
- Microbial Metabolites in Food Biotechnology
- Advanced Research in Systems and Signal Processing
- GNSS positioning and interference
- Calibration and Measurement Techniques
Brera Astronomical Observatory
2015-2024
National Institute for Astrophysics
2007-2024
Astronomical Observatory of Rome
2004-2024
University of Insubria
2015
Campbell Collaboration
2015
Liverpool John Moores University
2006-2014
The University of Sydney
2013
University of Ljubljana
2007-2009
University of Glasgow
2007
University of Milano-Bicocca
2007
Abstract We report the discovery and monitoring of near-infrared counterpart (AT2017gfo) a binary neutron-star merger event detected as gravitational wave source by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo (GW170817) short gamma-ray burst Fermi Gamma-ray Burst Monitor (GBM) Integral SPI-ACS (GRB 170817A). The evolution transient light is consistent with predictions for behavior “kilonova/macronova” powered radioactive decay massive neutron-rich nuclides...
With the first direct detection of merging black holes in 2015, era gravitational wave (GW) astrophysics began. A complete picture compact object mergers, however, requires an electromagnetic (EM) counterpart. We report ultraviolet (UV) and X-ray observations by Swift Nuclear Spectroscopic Telescope ARray (NuSTAR) EM counterpart binary neutron star merger GW170817. The bright, rapidly fading emission indicates a high mass ($\approx0.03$ solar masses) wind-driven outflow with moderate...
We report our observation of the short gamma-ray burst (GRB) GRB 170817A, associated to binary neutron star merger gravitational wave (GW) event GW 170817, performed in X-ray band with XMM-Newton 135 d after (on 29 December, 2017). find evidence for a flattening light curve respect previously observed brightening. This is also supported by nearly simultaneous optical Hubble Space Telescope and successive Chandra low-frequency radio observations recently reported literature. Since...
The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after using global network 32 radio telescopes. apparent is constrained to...
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...
Abstract Gamma-ray bursts (GRBs) are classified into long and short events. Long GRBs (LGRBs) associated with the end states of very massive stars, while (SGRBs) linked to merger compact objects. GRB 200826A was a peculiar event, because by definition it an SGRB, rest-frame duration ∼0.5 s. However, this event energetic soft, which is consistent LGRBs. The relatively low redshift ( z = 0.7486) motivated comprehensive, multiwavelength follow-up campaign characterize its host, search for...
Abstract The Lunar Gravitational-wave Antenna (LGWA) is a proposed array of next-generation inertial sensors to monitor the response Moon gravitational waves (GWs). Given size and expected noise produced by lunar seismic background, LGWA would be able observe GWs from about 1 mHz Hz. This make missing link between space-borne detectors like LISA with peak sensitivities around few millihertz future terrestrial Einstein Telescope or Cosmic Explorer. In this article, we provide first...
We present a carefully selected sub-sample of Swift long gamma-ray bursts (GRBs) that is complete in redshift. The sample constructed by considering only with favorable observing conditions for ground-based follow-up searches, which are bright the 15–150 keV Swift/BAT band, i.e., 1-s peak photon fluxes excess to 2.6 photons s−1 cm−2. composed 58 bursts, 52 them redshift completeness level 90%, while another two have constraint, reaching 95%. For three we no constraint on high allows us first...
We use a nearly complete sample of gamma-ray bursts (GRBs) detected by the Swift satellite to study correlations between spectral peak energy Epeak prompt emission, isotropic energetics Eiso and luminosity Liso. This GRB is characterized high level completeness in redshift (90 per cent). allows us probe an unbiased way issue related physical origin these against selection effects. find that one burst, 061021, outlier Epeak–Eiso correlation. Despite this case, we strong Epeak–Liso for sample....
We estimate the bulk Lorentz factor Gamma_0 of 31 GRBs using measured peak time their afterglow light curves. consider two possible scenarios for Gamma_0: case a homogeneous circumburst medium or wind density profile. The values are broadly distributed between few tens and several hundreds with average ~138 ~66 profile, respectively. find that isotropic energy luminosity correlate in similar way Gamma_0, i.e. Eiso Gamma_0^2 Liso Gamma_0^2, while Epeak Gamma_0. These correlations less...
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...
We present a carefully selected sample of short gamma-ray bursts (SGRBs) observed by the Swift satellite up to June 2013. Inspired criteria we used build similar bright long GRBs (the BAT6 sample), SGRBs with favorable observing conditions for redshift determination on ground, ending 36 events, almost half which measure. The completeness increases about 70% (with an average value z = 0.85) restricting those events that are in 15-150 keV Burst Alert Telescope energy band. Such flux-limited...
We derive the luminosity function φ(L) and redshift distribution Ψ(z) of short gamma-ray bursts (SGRBs) using all available observer-frame constraints (i.e. peak flux, fluence, energy duration distributions) large population Fermi SGRBs rest-frame properties a complete sample detected by Swift. show that steep ∝ L− α with ≥ 2.0 is excluded if full set considered. implement Markov chain Monte Carlo method to functions assuming intrinsic Ep−Liso Ep−Eiso correlations hold or, alternatively,...
Knowledge of the bulk Lorentz factor $\Gamma_{0}$ GRBs allows us to compute their comoving frame properties shedding light on physics. Upon collisions with circumburst matter, fireball a GRB starts decelerate, producing peak or break (depending density profile) in curve afterglow. Considering all bursts known redshift and an early coverage emission, we find 67 optical GeV curves at time $t_{\rm p}$. For another 106 set upper limit p}^{\rm UL}$. We show that p}$ is due dynamics deceleration...
In this paper, we compute rest-frame extinctions for the afterglows of a sample Swift gamma-ray bursts (GRBs) complete in redshift. The selection criteria are based on observational high-energy parameters prompt emission and therefore our should not be biased against dusty sight-lines. It is expected that inferences hold general population GRBs. Our main result optical/near-infrared extinction GRB does follow single distribution. 87 per cent events absorbed by less than 2 mag, 50 suffer from...
Multi-messenger astronomy received a great boost following the discovery of kilonova AT2017gfo, optical counterpart gravitational wave source GW170817 associated with short gamma-ray burst GRB 170817A. AT2017gfo was first that could be extensively monitored in time both photometrically and spectroscopically. Previously, only few candidates have been observed against glare afterglows. In this work, we aim to search fingerprints AT2017gfo-like emissions optical/NIR light curves 39 GRBs known...
Information on the spectral shape of prompt emission in gamma-ray bursts (GRB) is mostly available only at energies $\gtrsim10$ keV, where main instruments for GRB detection are sensitive. The origin this still very uncertain because apparent inconsistency with synchrotron radiation, which most obvious candidate, and resulting need considering less straightforward scenarios. inclusion data down to soft X-rays ($\sim$ 0.5 keV), a small fraction GRBs, has firmly established common presence...
Abstract We present James Webb Space Telescope (JWST) and Hubble (HST) observations of the afterglow GRB 221009A, brightest gamma-ray burst (GRB) ever observed. This includes first mid-IR spectra any GRB, obtained with JWST/Near Infrared Spectrograph (0.6–5.5 micron) Mid-Infrared Instrument (5–12 micron), 12 days after burst. Assuming that intrinsic spectral slope is a single power law, F ν ∝ − β , we obtain ≈ 0.35, modified by substantial dust extinction A V = 4.9. suggests above notional...
We present ground-based and HST optical infrared observations of XRF 100316D / SN 2010bh. It is seen that the light curves 2010bh evolve at a faster rate than archetype GRB-SN 1998bw, but similar to 2006aj, supernova was spectroscopically linked with 060218, non-GRB associated type Ic 1994I. estimate rest-frame extinction this event from our data be E(B-V)=0.18 +/- 0.08 mag. find V-band absolute magnitude M_{V}=-18.62 0.08, which faintest peak observed to-date for spectroscopically-confirmed...