F. Frontera
A5009212329- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Astronomy and Astrophysical Research
- SAS software applications and methods
- Nuclear Physics and Applications
- Stellar, planetary, and galactic studies
- Advanced X-ray Imaging Techniques
- Radiation Detection and Scintillator Technologies
- High-pressure geophysics and materials
- Advanced Semiconductor Detectors and Materials
- Geophysics and Gravity Measurements
- X-ray Spectroscopy and Fluorescence Analysis
- CCD and CMOS Imaging Sensors
- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Calibration and Measurement Techniques
- Mechanics and Biomechanics Studies
- Advanced X-ray and CT Imaging
- Crystallography and Radiation Phenomena
- Galaxies: Formation, Evolution, Phenomena
University of Ferrara
2015-2024
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2005-2024
Osservatorio di Astrofisica e Scienza dello Spazio
2019-2024
National Institute for Astrophysics
2013-2023
Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara
1995-2023
Kazan Federal University
2021
International Center for Relativistic Astrophysics
2019-2021
University of Palermo
2021
Fondazione Politecnico di Milano
2020
University of Nottingham
2020
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....
The JEM–X monitor provides X-ray spectra and imaging with arcminute angular resolution in the 3 to 35 keV band. good low energy response of plays an important role identification gamma ray sources analysis scientific interpretation combined data. is a coded aperture instrument consisting two identical, coaligned telescopes. Each detectors has sensitive area 500 cm2, views sky through its own mask. masks are inverted respect each other 3' across effective field view about 10° diameter.
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...
We present and discuss the photometric spectroscopic evolution of peculiar SN 1998bw, associated with GRB 980425, through an analysis optical near-IR data collected at ESO-La Silla. The data, spanning period from day -9 to +376 (relative B maximum), have shown that this supernova (SN) was unprecedented, although somewhat similar 1997ef. Maximum expansion velocities as high 3 × 104 km s-1 some extent mask its resemblance other Type Ic SNe. At intermediate phases, between photospheric fully...
BeppoSAX/PDS experiment is one of four narrow field instruments the BeppoSAX payload, that also includes two wide cameras. The goal PDS to extend energy range hard X–rays. operative 15 300 keV, where can perform sensitive spectral and temporal studies celestial sources. detector composed 4 actively shielded NaI(Tl)/CsI(Na) phoswich scintillators with a total geometric area view 13 (FWHM). In this paper we describe design discuss its functional performance calibration data analysis system.
The results of a worldwide coordinated observational campaign on the broad-lined Type Ic supernova (SN Ic) 2003jd are presented. In total, 74 photometric data points and 26 spectra were collected using 11 different telescopes. SN is one most luminous ever observed. A comparison with other supernovae (SNe confirms that represents an intermediate case between broad-line events (2002ap, 2006aj) highly energetic SNe (1997ef, 1998bw, 2003dh, 2003lw), ejected mass Mej= 3.0 ± 1 M⊙ kinetic energy...
We report on the discovery of two emission features observed in x-ray spectrum afterglow gamma-ray burst (GRB) 16 December 1999 by Chandra X-ray Observatory. These are identified with Ly(alpha) line and narrow recombination continuum hydrogenic ions iron at a redshift z = 1.00 +/- 0.02, providing an unambiguous measurement distance GRB. Line width intensity imply that progenitor GRB was massive star system ejected, before event, quantity approximately 0.01 mass sun velocity 0.1 speed light,...
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...
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,...
GRB 221009A is the brightest gamma-ray burst ever detected since discovery of this kind energetic explosions. However, an accurate measurement prompt emission properties very challenging due to its exceptional brightness. With joint observations \textit{Insight}-HXMT and GECAM-C, we made unprecedentedly during first $\sim$1800 s 221009A, including precursor, main (ME, which dominates in flux), flaring early afterglow, hard X-ray soft band from $\sim$ 10 keV 6 MeV. Based on GECAM-C...
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 propose a model to explain how Gamma Rays Burst can take place days or years after supernova explosion. Our is based on the conversion of pure hadronic star (neutron star) into made at least in part deconfined quark matter. The process be delayed if surface tension interface between and deconfined-quark-matter phases taken account. nucleation time (i.e. form critical-size drop matter) extremely long mass small. Via accretion dramaticaly reduced finally converted stable configuration. A...
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...