Tag: XMM

High temperature plasma in solar and low-mass stars. The study: “Empirical prediction of plasma emission measure distributions and X-EUV spectra of late-type stars” of A. Maggio (INAF-OAPA) recently appeared on The Astrophysical Journal

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Measured the amount of plasma between 10000 and 30 million degrees—responsible for the emission of extreme UV radiation and soft X-rays—in a sample of Sun-like and low-mass stars.   Sun-like stars (spectral classes FGK) and low-mass stars (spectral class M) host in their outer atmospheres (the corona) plasma at temperatures of millions of degrees. Such high temperatures are reached through

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X-rays from SN1987A: shocks, circumstellar clouds and ionised oxygen described in two recent publications

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Analysis of X-ray observations of the SN1987A supernova remnant, obtained by the XMM-Newton satellite, provides new insights into the interaction between the supernova shock wave and the circumstellar material, as well as the oxygen abundance in the remnant.   The SN1987A supernova remnant is undoubtedly one of the most iconic objects for studying supernovae, their remnants, and the final stages

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The XUV emission of the star HIP67522 and the evolution of its exoplanet. The study: “XUV irradiation of young planetary atmospheres. Results from a joint XMM-Newton and HST observation of HIP67522” of A. Maggio (INAF-OAPA) appeared on A&A

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Despite the wide array of telescopes and satellites available to the astronomical community, there is a type of radiation to which we are virtually blind: the extreme UV band. This is high-energy radiation with a wavelength that ranges from the Lyman-α emission, caused by hydrogen atoms whose electron transitions from the innermost orbital (the ground state) to the second (n=2),

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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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A study on the coronal activity in a complete sample of M stars nearby to the Sun. The paper: “Complete X-ray census of M dwarfs in the solar neighborhood. I. GJ 745 AB: Coronal-hole stars in the 10 pc sample” of M. Caramazza (Eberhard-Karls Universität Tübingen) appeared on A&A

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The corona is the outermost part of the atmosphere of the vast majority of stars, where the plasma is heated to millions of degrees by stellar magnetic activity. Since both the intensity and the topology of the stellar magnetic fields depend on the internal structure of stars, the study of coronal activity allows astronomers to better understand both the high-energy

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A superflare observed in the M star AD Leo. The study: “The Great Flare of 2021 November 19 on AD Leo. Simultaneous XMM-Newton and TESS observations” of B. Stelzer (Eberhard-Karls-Universität Tübingen) appeared on A&A

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Flares are transient and energetic phenomena that occur in most stars and can be observed with high spatial and temporal resolution in the Sun. These phenomena are triggered by a sudden release of energy previously stored in the star’s magnetic field, which, after a sequence of events, leads to extreme heating of the stellar plasma. The heated plasma then rapidly

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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 remnants as particle accelerators. The study: “The supernova remnant SN 1006 as a Galactic particle accelerator” of R. Giuffrida (UniPA/INAF-OAPA) recently appeared on Nature Communication

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Our planet is constantly bombarded by energetic particles (mainly protons) called “cosmic rays“. The study of cosmic rays is a leading science topic given its importance in several fields, such as the study of the effects on instrumentation and astronauts in space, where the natural protection against these particles provided by the magnetic field of Earth is low or null.

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The interaction between star and planet triggers more energetic flares. The study: “X-ray variability of HD 189733 across eight years of XMM-Newton observations” of I. Pillitteri (INAF – OAPA) recently appeared on A&A

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The corona is the outermost part of the atmosphere in stars with intermediate and low mass. In this region, which is extended for several stellar radii, the plasma can reach temperatures of several million degrees, emitting mainly X-ray radiation. The coronal temperature varies over a range of several orders of magnitude as a function of several stellar parameters, such as

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Photoevaporation in young planets. The study: “New Constraints on the Future Evaporation of the Young Exoplanets in the V1298 Tau System” of A. Maggio (INAF – OAPA) recently appeared on ApJ

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The search for young exoplanets is crucial to our understanding of the planetary formation process and the early evolution of planets. The disc of gas and dust from which planets form, in fact, typically disperse in a few million of years. Before that, the young planets interact with all the material orbiting around the star within the disk, triggering important

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