A5038985873- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Particle Detector Development and Performance
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Nuclear Physics and Applications
- SAS software applications and methods
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- CCD and CMOS Imaging Sensors
- Geophysics and Gravity Measurements
- Advanced X-ray and CT Imaging
- Solar and Space Plasma Dynamics
- Statistical and numerical algorithms
- Neutrino Physics Research
- Medical Imaging Techniques and Applications
- Advanced Semiconductor Detectors and Materials
- Advanced X-ray Imaging Techniques
- Particle physics theoretical and experimental studies
National Institute for Astrophysics
2015-2024
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2014-2024
Osservatorio di Astrofisica e Scienza dello Spazio
2016-2024
Osservatorio astronomico di Bologna
2021
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2004-2021
Goddard Space Flight Center
2021
Pontificia Universidad Católica de Chile
2021
Kazan Federal University
2021
Astronomical Observatory of Capodimonte
2019
Laboratoire d’Astrophysique de Marseille
2018
We present the main results of a study spectral and energetics properties twelve gamma-ray bursts (GRBs) with redshift estimates. All GRBs in our sample were detected by BeppoSAX broad energy range (2–700 ). From estimates good-quality time–integrated spectra we deduce their cosmological rest frames. are satisfactorily represented Band model, no significant soft X–ray excesses or absorptions. find positive correlation between estimated total (isotropic) energies 1–10 000 (Erad) redshifts z....
This White Paper, submitted to the recent ESA call for science themes define its future large missions, advocates need a transformational leap in our understanding of two key questions astrophysics: 1) How does ordinary matter assemble into scale structures that we see today? 2) do black holes grow and shape Universe? Hot gas clusters, groups intergalactic medium dominates baryonic content local Universe. To understand astrophysical processes responsible formation assembly these structures,...
Gamma-ray bursts (GRBs) serve as powerful probes of the early Universe, with their luminous afterglows revealing locations and physical properties star forming galaxies at highest redshifts, potentially locating first generation (Population III) stars. Since GRB have intrinsically very simple spectra, they allow robust redshifts from low signal to noise spectroscopy, or photometry. Here we present a photometric redshift z~9.4 for Swift-detected 090429B based on deep observations...
The correlation between the cosmological rest-frame nuFnu spectrum peak energy, Ep,i, and isotropic equivalent radiated Eiso, discovered by Amati et al. in 2002 confirmed/extended subsequent osbervations, is one of most intriguing debated observational evidences Gamma-Ray Bursts (GRB) astrophysics. In this paper I provide an update a re-analysis Ep,i - Eiso basing on updated sample consisting 41 long GRBs/XRFs with firm estimates z observed Ep,obs, 12 GRBs uncertain valeus and/or 2 short...
We have used the Ep,i–Eiso correlation of gamma-ray bursts (GRBs) to measure cosmological parameter ΩM. By adopting a maximum likelihood approach which allows us correctly quantify extrinsic (i.e. non-Poissonian) scatter correlation, we constrain (for flat universe) ΩM 0.04–0.40 (68 per cent confidence level), with best-fitting value ΩM∼ 0.15, and exclude ΩM= 1 at >99.9 level. If release assumption universe, still find evidence for low (0.04–0.50 68 level) weak dependence dispersion on ΩΛ...
Abstract The detection of the accelerated expansion Universe has been one major breakthroughs in modern cosmology. Several cosmological probes (Cosmic Microwave Background, Supernovae Type Ia, Baryon Acoustic Oscillations) have studied depth to better understand nature mechanism driving this acceleration, and they are being currently pushed their limits, obtaining remarkable constraints that allowed us shape standard model. In parallel that, however, percent precision achieved recently...
XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to Astronomy. At time of writing XIPE in competitive phase A as fourth medium size ESA (M4). It promises reopen polarimetry window high energy Astrophysics after more than 4 decades thanks detector that efficiently exploits photoelectric effect and optics with large effective area. uniqueness time-spectrally-spatially- resolved breakthrough astrophysics fundamental physics. Indeed payload consists three Gas Pixel Detectors...
We provide an updated assessment of the power Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at TeV scale, via associated gamma-ray signal from pair-annihilating particles in region around Galactic centre. find that CTA will open a new window discovery potential, significantly extending range robustly testable models given standard cuspy profile density distribution. Importantly, even cored profile, projected sensitivity be sufficient probe various...
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...
We present multicolor optical and two-frequency radio observations of the bright BeppoSAX event GRB 990510. Neither well-sampled decay nor are consistent with simple spherical afterglow models. The achromatic steepening in band early afterglow, which both occur at t ~ 1 day, evidence for hydrodynamical evolution source can be most easily interpreted by models gamma-ray burst ejecta collimated a jet. Employing jet model to explain observations, we derive opening angle θ0 = 0.08(n/1 cm-3)1/8,...
The extremely energetic Fermi GRBs 080916C, with its Eiso of ~ 10^{55} erg in 1 keV - 10 GeV and intense emission, 090323 give us a unique opportunity to test the reliability extension spectral energy correlations. Based on Konus/WIND measurements, we find that both events are fully consistent updated (95 as April 2009) Ep,i correlation, thus further confirming extending it pointing against possible flattening or increased dispersion at very high energies. This also suggests physics behind...
In the current framework, standard parametrization of our Universe is so-called Lambda cold dark matter (ΛCDM) model. Recently, a ∼4 σ tension with ΛCDM model was shown to exist via model-independent Hubble diagram type Ia supernovae (SNe Ia) from JLA survey and quasars. Model-independent approaches independent samples over wide redshift range are key testing this any possible systematic errors. Here we present an analysis combined SNe Ia, quasars, gamma-ray bursts (GRBs) check agreement...
Gamma-ray bursts are the most energetic explosions in Universe. They detectable up to very high redshifts, therefore can be used study expansion rate of Universe and investigate observational properties dark energy, provided that empirical correlations between spectral intensity appropriately calibrated. We type Ia supernova luminosity distances calibrate correlation peak photon $E_{p, i}$, isotropic equivalent radiated $ E_{iso}$ GRBs. With this correlation, we tested reliability applying...
eXTP is a science mission designed to study the state of matter under extreme conditions density, gravity and magnetism. Primary goals are determination equation at supra-nuclear measurement QED effects in highly magnetized star, accretion strong-field regime gravity. targets include isolated binary neutron stars, strong magnetic field systems like magnetars, stellar-mass supermassive black holes. The carries unique unprecedented suite state-of-the-art scientific instruments enabling for...
ABSTRACT We here propose a new model-independent technique to overcome the circularity problem affecting use of gamma-ray bursts (GRBs) as distance indicators through Ep−Eiso correlation. calibrate correlation and find GRB moduli that can be used constrain dark energy models. observational Hubble data approximate cosmic evolution Bézier parametric curve obtained linear combination Bernstein basis polynomials. In doing so, we build up set consisting 193 moduli. combine this sample with...
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...
THESEUS, one of the two space mission concepts being studied by ESA as candidates for next M5 within its Comsic Vision programme, aims at fully exploiting Gamma-Ray Bursts (GRB) to solve key questions about early Universe, well becoming a cornerstone multi-messenger and time-domain astrophysics. By investigating first billion years Universe through high-redshift GRBs, THESEUS will shed light on main open issues in modern cosmology, such population primordial low mass luminosity galaxies,...
The dissipation process of GRB prompt emission is still unknown. Study temporal variability may provide a unique way to discriminate the imprint inner engine activity from geometry and propagation related effects. We define minimum timescale (MVT) as shortest duration individual pulses that shape light curve for sample GRBs test correlations with peak luminosity, Lorentz factor, jet opening angle. compare these predictions recent numerical simulations relativistic structured -- possibly...
We report the discovery of a transient equivalent hydrogen column density with an absorption edge at approximately 3.8 kiloelectron volts in spectrum prompt x-ray emission gamma-ray burst (GRB) 990705. This feature can be satisfactorily modeled photoelectric by medium located redshift 0.86 and iron abundance 75 times solar one. The behavior is attributed to strong ionization produced circumburst GRB photons. high points existence environment enriched supernova along line sight. explosion...