Tag: resti di supernova

The acceleration of cosmic rays in supernova remnants depends on the interaction with the surrounding medium. The study: “Time evolution of the synchrotron X-ray emission in Kepler’s SNR: the effects of turbulence and shock velocity” of V. Sapienza (UNIPA/INAF-OAPA) appeared on ApJ

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The role of supernova remnants (expanding clouds produced by supernovae) in the acceleration of cosmic rays (high-energy particles present in various astrophysical environments) has been known since 1995. The discovery, made by astronomers from Kyoto University, was made possible by identifying the presence of non-thermal X-ray emission in the supernova remnant SN 1006. X-rays are a type of high-energy radiation

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A study on the processes responsible for the acceleration of particles in shocks. The study: “Individual particle approach to the diffusive shock acceleration. Effect of the non-uniform flow velocity downstream of the shock” of O. Petruk (INAF-OAPA) appeared on A&A

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Our planet is constantly bombarded by highly energetic particles known as ‘cosmic rays‘. The spectrum of cosmic rays up to energies of 1015 electronvolts (eV) is formed by the sources in our Galaxy, while particles with observed energies up to 1021 eV should have extra-galactic origin. The cosmic ray spectrum follows a power law, meaning that the flux of particles with a given

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Superfast fragments and X-ray emission in the supernova remnant SN 1006. The study: “Indication of a fast ejecta fragment in the atomic cloud interacting with the southwestern limb of SN 1006” of R. Giuffrida (UNIPA/INAF) appeared on A&A

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Supernova remnants, which are nebulae produced by explosion of supernovae and undergoing rapid expansion, typically serve as intense sources of high-energy radiation, particularly in the form of X-ray emissions. This radiation can be of two different types: thermal and non-thermal. Thermal radiation is emitted by dense material and is contingent upon the temperature of the emitting gas. To emit X-rays,

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Simulated the XRISM observations of the iconic supernova remnant SN1987 A. The study: “Probing Shocked Ejecta in SN 1987A: A novel diagnostic approach using XRISM−Resolve” of V. Sapienza (UNIPA/OAPA) accepted on ApJL

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SN1987 A is one of the most significant objects for studying supernova explosions and their remnants. This is because it is the only core-collapse supernova that has occurred relatively close to us (approximately 170000 light-years away, in the Large Magellanic Cloud) in the modern epoch. Therefore, it is the sole object of this type for which we have telescope observations

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γ-ray emission from the supernova remnants in the Large Magellanic Cloud. The paper: “High-energy γ-ray detection of supernova remnants in the Large Magellanic Cloud” of R. Campana (INAF – OAS) recently appeared on MNRAS

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Supernova remnants are expanding nebulae produced by the explosion of high-mass stars. They are of great interest for understanding various physical processes and the final evolutionary stages of massive stars. Observations of supernova remnants in gamma rays are particularly important as they shed light on high-energy processes, such as the acceleration of cosmic rays (charged particles at very high energies).

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The magnetic field in SN1987A revealed from radio observations. The study: “Polarized radio emission unveils the structure of the pre-supernova circumstellar magnetic field and the radio emission in SN1987A” of O. Petruk (INAF-OAPA) appeared on A&A

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Without any doubts, the supernova remnants SN1987A is the one that taught us more about this class of objects and supernova exposions. Produced by a supernova exploded in the Large Magellanic Cloud on February 23rd 1987, this is the only case in which we have observations of the progenitor, of the supernova explosion, and in which we follow the development

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Different regimes of particle acceleration in supernova remnants. The study: “A Spatially Resolved Study of Hard X-Ray Emission in Kepler’s Supernova Remnant: Indications of Different Regimes of Particle Acceleration” of V. Sapienza (UNIPA/OAPA) appeared on ApJ

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Cosmic rays are high-energy charged particles which continuously hit our planet. These particles are accelerated up to such high velocities in different astronomical environments, among which supernova remnants seems to be particularly important. These objects are nebulae in rapid expansion generated by the explosions of very massive stars. In supernova remnants, particle acceleration seems to occurr along the expanding shock

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Supernova explosions can trigger star formation events. The study: “Negative and positive feedback from a supernova remnant with SHREC: a detailed study of the shocked gas in IC443” of G. Cosentino (Chalmers University of Technology) recently appeared on MNRAS

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A supernova is the final act of the evolution of a massive star. These spectacular explosions are among the most energetic events we observe in the Universe, and they can seriously impact the surrounding environment. In particular, during the expansions of the supernova remnants, which are the expanding clouds produced by supernova explosions, the process of star formation in the

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Supernova explosions produced by LBV stars. The study: “Modeling the remnants of core-collapse supernovae from luminous blue variable stars” of S. Ustamujic (INAF-OAPA) recently appeared on Astronomy & Astrophysics

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LBV (Luminous Blue Variable) stars are massive and unstable stars characterized by large mass-lost due to intense stellar winds and aperiodic bursts. Due to their instability, LBV stars are also variable, with quasi-periodic oscillations of their luminosity of the order of 0.5-2 magnitudes. Typical examples of this class of stars are: the supergiant S Doradus in the Large Magellanic Clouds,

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The role of the magnetic field during the evolution of supernova remnants i. The study: “Magneto-hydrodynamic simulations of young supernova remnants and their energy-conversion phase” of O. Petruk (IAPMM NASU) recently appeared on MNRAS

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Supernova explosions are sorted into two categories: The thermonuclear explosions triggered by white dwarfs in close binary systems (type Ia) and those triggered by the gravitational collapse of the core of massive stars (type Ib/c and II). Because of the paucity of known supernova remnants younger than 1000 years, astronomers developed several models describing the evolution of supernova remnants to

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