A5047138394- Gamma-ray bursts and supernovae
- SAS software applications and methods
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Advanced X-ray and CT Imaging
- Solar and Space Plasma Dynamics
- Cosmology and Gravitation Theories
- Statistical and numerical algorithms
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Spectroscopy and Chemometric Analyses
- Atmospheric Ozone and Climate
Agenzia Spaziale Italiana
2015-2024
Astronomical Observatory of Rome
2015-2024
National Institute for Astrophysics
2014-2024
Istituto Nazionale di Ricerca Metrologica
2010-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2021-2024
University of Padua
2021-2024
Foundation for Research and Technology Hellas
2023
University of Siena
2023
Boston University
2023
Turku Centre for Computer Science
2023
(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...
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...
We present the first catalog of active galactic nuclei (AGNs) detected by Large Area Telescope (LAT), corresponding to 11 months data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 γ-ray sources located at high Galactic latitudes (|b|>10°) that are with a test statistic greater than 25 and associated statistically AGNs. Some multiple AGNs, consequently, 709 comprising 300 BL Lacertae objects, 296 flat-spectrum radio quasars, 41 AGNs other types, 72...
We report on the observation of bright, long gamma-ray burst, GRB 090902B, by Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) instruments on-board Fermi observatory. This was one brightest GRBs to have been observed LAT, which detected several hundred photons during prompt phase. With a redshift z = 1.822, this burst is among most luminous Fermi. Time-resolved spectral analysis reveals significant power-law component in LAT data that distinct from usual Band model emission seen...
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to September 2009, for total 76 GRBs, and present an additional three pre-Swift not included in earlier sample. Furthermore, we publish 840 new points 42 GRB afterglows, sets 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A 080810. analyzed light curves all derived spectral energy distributions with best quality, allowing us estimate host...
We present X-Shooter/VLT observations of a sample 36 accreting low-mass stellar and sub-stellar objects (YSOs) in the Lupus star forming region, spanning range mass from ~0.03 to ~1.2Msun, but mostly with 0.1Msun < Mstar 0.5Msun. Our aim is twofold: firstly, analyse relationship between excess-continuum line emission accretion diagnostics, and, secondly, investigate properties terms physical central object. The luminosity (Lacc), it rate (Macc), derived by modelling excess emission, UV...
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 propose a scenario where blazars are classified as flat-spectrum radio quasars (FSRQs), BL Lacs, low synchrotron, or high synchrotron peaked objects according to varying mix of the Doppler boosted radiation from jet, emission accretion disk, broad line region, and light host galaxy. In this framework peak energy power (nu_peak) in is independent source type luminosity. test new approach, which builds upon unified schemes, using extensive Monte Carlo simulations show that it can provide...
Gamma-ray bursts (GRBs) have been separated into two classes, originally along the lines of duration and spectral properties, called "short/hard" "long/soft." The latter conclusively linked to explosive deaths massive stars, while former are thought result from merger or collapse compact objects. In recent years, indications accumulating that short/hard versus long/soft division does not map directly onto what would be expected classes progenitors, leading a new classification scheme Type I...
Abstract A neutrino with energy ∼290 TeV, IceCube-170922A, was detected in coincidence the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, chance being rejected at ∼3 σ level. We monitored very-high-energy (VHE) band Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes for ∼41 hr from 1.3 to 40.4 days after detection. Day-timescale variability is clearly resolved. interpret quasi-simultaneous and broadband electromagnetic observations a novel one-zone...
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...
The mergers of binary compact objects such as neutron stars and black holes are central interest to several areas astrophysics, including the progenitors gamma-ray bursts (GRBs), sources high-frequency gravitational waves likely production sites for heavy element nucleosynthesis via rapid capture (the r-process). These elements include some great geophysical, biological cultural importance, thorium, iodine gold. Here we present observations exceptionally bright burst GRB 230307A. We show...
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...
The only supernovae (SNe) to show gamma-ray bursts (GRBs) or early x-ray emission thus far are overenergetic, broad-lined type Ic SNe (hypernovae, HNe). Recently, SN 2008D has shown several unusual features: (i) weak flash (XRF), (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical HNe, and (iv) development helium as in Ib. Detailed analysis shows that was not a normal supernova: Its explosion energy (E approximately 6x10(51) erg) ejected mass [ 7 times Sun...
We present optical, X-ray and gamma-ray observations of GRB 111209A, observed at a redshift z = 0.677. show that this event was active in its prompt phase for about 25000 s, making it the longest burst ever observed. This rare could have been detected up to ∼ 1.4 gamma-rays. Compared other long bursts (GRBs), 111209A is clear outlier energy-fluence duration plane. The high-energy emission shows no sign strong blackbody component, signature tidal disruption event, or supernova shock breakout....
We present data and initial results from VLT/X-Shooter emission-line spectroscopy of 96 galaxies selected by long γ-ray bursts (GRBs) at 0.1 <z< 3.6, the largest sample GRB host spectra available to date. Most our GRBs were detected Swift 76% are 0.5 2.5 with a median zmed ~ 1.6. Based on Balmer and/or forbidden lines oxygen, nitrogen, neon, we measure systemic redshifts, star formation rates (SFR), visual attenuations (AV), oxygen abundances (12 + log (O/H)), widths (σ). study hosts up z...