A5035722943- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Particle Detector Development and Performance
- Advanced X-ray and CT Imaging
- Nuclear Physics and Applications
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
Gran Sasso Science Institute
2021-2024
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso
2021-2024
Istituto Nazionale di Fisica Nucleare
2024
University of Rome Tor Vergata
2021
A long gamma-ray burst (GRB) is observed when the collapse of a massive star produces an ultrarelativistic outflow pointed toward Earth. Gamma-ray spectra GRBs are smooth, typically modeled by joint power-law segments describing continuum, with no detected spectral lines. We report significant (>6σ) narrow emission feature at ~10 mega-electron volts (MeV) in spectrum bright GRB 221009A. Over 80 seconds, it evolves energy (~12 to ~6 MeV) and luminosity (~1.1 <0.43 × 10
Despite more than fifty years of gamma-ray burst (GRB) observations, several questions regarding the origin prompt emission, particularly at high energies, remain unresolved. We present a comprehensive analysis 35 GRBs observed by \textit{Fermi}/GBM and \textit{Fermi}/LAT over past 15 years, focusing on nature high-energy (HE, E$>$100 MeV) emission during phase. Our study combines temporal spectral analyses to investigate synchrotron spanning energy range from 10 keV 100 GeV explore possible...
Neutrino emission from γ -ray bursts (GRBs) has been sought for a long time, and stringent limits on the most accredited GRB models have obtained IceCube. Multiwavelength observations of last decades improved our knowledge parameters, such as Lorentz factor luminosity, which can vary one to another by several orders magnitude. Empirical correlations among parameters identified during prompt phase, with direct implications models. In this work, we use PSLab open-access code, developed IceCube...
Abstract The emission region of γ -ray bursts (GRBs) is poorly constrained. uncertainty on the size dissipation site spans over 4 orders magnitude (10 12 –10 17 cm) depending unknown energy composition GRB jets. joint multiband analysis from soft X-rays to high energies (up ∼1 GeV) one most energetic and distant GRBs, 220101A ( z = 4.618), allows us make an accurate distinction between prompt early afterglow emissions. enormous amount released by E iso ≈ 3 × 10 54 erg) spectral cutoff at...
The highly variable and energetic pulsed emission of a long gamma-ray burst (GRB) is thought to originate from local, rapid dissipation kinetic or magnetic energy within an ultra-relativistic jet launched by newborn compact object, formed during the collapse massive star. spectra GRB pulses are best modelled power-law segments, indicating dominance non-thermal radiation processes. Spectral lines in X-ray soft $\gamma$-ray regime for afterglow have been searched intensively, but never...
Abstract An energetic γ-ray burst (GRB), GRB 211211A, was observed on 2021 December 11 by the Neil Gehrels Swift Observatory. Despite its long duration, typically associated with bursts produced collapse of massive stars, discovery an optical-infrared kilonova and a quasiperiodic oscillation during gamma-ray precursor points to compact object binary merger origin. The complete understanding this nearby 1 Springer Nature LATEX template 2 GeV emission from (∼ billion light-years) will...
Observing and understanding the origin of very-high-energy (VHE) spectral component in gamma-ray bursts (GRBs) has been challenging because lack sensitivity MeV-GeV observations, so far. The majestic GRB 221009A, known as brightest all times (BOAT), offers a unique opportunity to identify components during prompt early afterglow phases probe their origin. Analyzing simultaneous observations spanning from keV TeV energies, we identified two distinct initial 20 minutes burst. second peaks...
<title>Abstract</title> Observing and understanding the origin of very-high-energy (VHE) spectral component in gamma-ray bursts (GRBs) has been challenging because lack sensitivity MeV-GeV observations, so far. The majestic GRB 221009A, known as brightest all times (BOAT), offers a unique opportunity to identify components during prompt early afterglow phases probe their origin. Analyzing simultaneous observations spanning from keV TeV energies, we identified two distinct initial 20 minutes...
For over two decades, gamma-ray burst (GRB) prompt emission spectra were modelled with smoothly-broken power laws (Band function), and a positive tight correlation between the spectral rest-frame peak energy $E_p$ total isotropic-equivalent luminosity $L_{iso}$ was found, constituting so-called Yonetoku relation. However, more recent studies show that many are well described by synchrotron radiation model, hence significantly deviating from Band function. In this work, we test impact of...
For over two decades, gamma-ray burst (GRB) prompt emission spectra were modeled with smoothly broken power laws (Band function), and a positive tight correlation between the spectral rest-frame peak energy total isotropic-equivalent luminosity was found, constituting so-called Yonetoku relation. However, more recent studies show that many are well described by synchrotron radiation model, hence significantly deviate from Band function. In this work, we test impact of refined model such as...
Neutrino emission from gamma-ray bursts (GRBs) has been sought for a long time, and stringent limits on the most accredited GRB models have obtained IceCube. Multi-wavelength observations of last decades improved our knowledge parameters, such as Lorentz factor luminosity, which can vary one to another by several orders magnitude. Empirical correlations among parameters identified during prompt phase, with direct implications models. In this work, we use PSLab open-access code, developed...
The emission region of $\rm γ$-ray bursts (GRBs) is poorly constrained. uncertainty on the size dissipation site spans over 4 orders magnitude ($\rm 10^{12}-10^{17}$ cm) depending unknown energy composition GRB jets. joint multi-band analysis from soft X-rays to high energies (up \sim$ 1 GeV) one most energetic and distant 220101A (z = 4.618) allows us for an accurate distinction between prompt early afterglow emissions. enormous amount released by E_{iso} \approx 3 \times10^{54}$ erg)...
An energetic $\rm γ$-ray burst (GRB), GRB 211211A, was observed on 2021 December 11 by the Neil Gehrels Swift Observatory. Despite its long duration, typically associated with bursts produced collapse of massive stars, discovery an optical-infrared kilonova and a quasi-periodic oscillation during gamma-ray precursor points to compact object binary merger origin. The complete understanding this nearby ($\sim$ 1 billion light-years) will significantly impact our knowledge progenitors physical...
We want to explore the geometrical structure and mutual interactions of innermost components broad line radio galaxy (BLRG) 3C 215, with particular interest in accretion ejection mechanisms involving central supermassive black hole (SMBH). compare these observational features ones RQ Seyfert 1 galaxies. Investigating their differences it is possible understand more about jet launching mechanisms, why this phenomenon efficient only a small fraction all AGNs. Using high quality data from...
We think that gamma-ray bursts have two types of progenitors, each them producing flashes with different durations, long or short. In December 2021, the most bizarre burst ever not only broke our progenitor paradigm, but also showed a late-time excess gamma-rays never observed before. Both these mysteries common protagonist: coincident detection kilonova.