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D.D. 362/2024 Pubblica selezione per titoli ed eventuale colloquio per il conferimento di un assegno di ricerca di professionalizzazione, della durata di 12 mesi, eventualmente prorogabili, dal titolo “Supporto alle attività MAIV del sistema “Camere” della missione PLATO”, nell’ambito del progetto PLATO – Fase D

Pubblica selezione per titoli ed eventuale colloquio per il conferimento di un assegno di ricerca di professionalizzazione, della durata di 12 mesi, eventualmente prorogabili, dal titolo “Supporto alle attività MAIV […]

DD 392/2024 Bando di selezione per titoli ed eventuale colloquio per il conferimento di n. 2 assegni di ricerca di “professionalizzazione” della durata di 12 mesi, eventualmente prorogabili, dal titolo “Diagnostica e modellistica di eventi eruttivi nell’atmosfera solare ”

Bando di selezione per titoli ed eventuale colloquio per il conferimento di n. 2 assegni di ricerca di "professionalizzazione" della durata di 12 mesi, eventualmente prorogabili, dal titolo “Diagnostica e modellistica di eventi eruttivi nell'atmosfera solare ”, nell’ambito della Partecipazione […]

D.D. 393/24 Bando di concorso per titoli ed esame, relativo al reclutamento di n. 2 unità di personale inquadrato nel profilo di Ricercatore III livello a tempo determinato della durata di dodici mesi, per lo svolgimento delle attività di “Astrosismologia, Rotazione e Attività Stellare nell’ambito della missione PLATO dell’ESA: programmazione e validazione di procedure di modellizzazione e analisi dati” nell’ambito del progetto PLATO

Bando di concorso per titoli ed esame, relativo al reclutamento di n. 2 unità di personale inquadrato nel profilo di Ricercatore III livello a tempo determinato della durata di dodici […]

The Hot Neptune Desert

Sede A. Riccò Via Santa Sofia 78, Catania

The vast majority of close-in planets are either massive hot Jupiters capable of holding their atmosphere against the stellar photoevaporation or small rocky planets completely drained by the stellar radiation. We observe an unexpected dearth of highly irradiated Neptune- and Saturn-like planets orbiting their host star in less than 4-10 days, called "Hot Neptune Desert". In this talk, I will present our recent findings from uniformly vetting 250 hot Neptune TESS candidates using a two-step vetting technique, as well as discuss a cutting-edge approach to examine the problem under a new perspective. I will also discuss how the PLATO mission may enhance our understanding of the Hot Neptunes.
We will present some recent results - obtained by using this updated observational and theoretical framework - about the formation and early evolution of the Milky Way.

Notte Europea dei Ricercatori 2024

In occasione della Notte Europea dei Ricercatori 2024, l’INAF-Osservatorio Astrofisico di Catania ha organizzato varie attività per il pubblico che si svolgeranno tra il 27 e il 28 settembre.

Unraveling Space Weathering on Planetary and Astrophysical Surfaces

Sede A. Riccò Via Santa Sofia 78, Catania

It is well known that the interaction of energetic ions, electrons and photons with surfaces and interfaces leads to non-thermal desorption via a process typically referred to as desorption induced by electronic transitions (DIET).  When DIET involves either electrons or photons, these processes are generally referred to as electron-stimulated desorption and photon-stimulated desorption (PSD), respectively.  Recent attention has focused on understanding the role of non-thermal “space weathering” in the processing of interstellar grains and ices.
Specifically, there is deep interest in understanding the radiation processing of carbon grains in the solar nebula and unraveling the H2O formation mechanisms in solar nebula and planetary systems, including the Moon. Using graphite grains, the VUV photon-simulated oxidation of carbon grains via reactive scattering of water fragments produced by dissociative electron attachment at the buried interface was examined. The results suggested that VUV PSD at the buried water:carbon grain interface may help control the carbon inventory during planet formation. The inverse process, (i.e, the formation of water) may happen on metal-oxide samples such as mineral grains and lunar regolith samples, that contain or are terminated by hydroxyl groups. Solar wind space weathering experiments of several Apollo lunar samples demonstrated that thermally activated recombinative desorption (RD) can be H2O sources and that electron-stimulated reactive scattering to produce water may also be occurring, especially when the Moon is in the magnetopause.  RD can occur on a diurnal basis on the Moon and is prevalent during meteoroid impacts. The latter is simulated by laser irradiation studies followed by state and velocity resolved detection of the produced water.  Finally, evidence of space weathering and surface alteration has also been revealed using spatially resolved, high-resolution nanoscale Fourier transform infrared imaging/spectroscopy correlated with photoluminescence (PL) on Apollo samples with different origins and history.

D.D. 499/2024 Pubblica selezione per titoli e colloquio per il conferimento di un assegno di ricerca di professionalizzazione, della durata di 12 mesi, eventualmente prorogabili, dal titolo “Sviluppo di tecniche di Visual Analytics e Machine Learning per il Progetto SKAVA”, nell’ambito del progetto SKAVA: SKA Visual Analytics

Pubblica selezione per titoli e colloquio per il conferimento di un assegno di ricerca di professionalizzazione, della durata di 12 mesi, eventualmente prorogabili, dal titolo “Sviluppo di tecniche di Visual […]

Stellar-wind-fed magnetospheres of magnetic massive stars

Sede A. Riccò Via Santa Sofia 78, Catania

A subpopulation (~9%) of hot (OB) stars exhibit strong (B~100-10,000 G), large-scale (often predominantly dipolar) magnetic fields that channel their stellar wind outflows into circumstellar magnetospheres. For young, rapidly rotating B-stars that have not yet been spun down by wind-magnetic braking, wind material can be trapped between the Kepler co-rotation radius (RK) and the Alfven radius (RA), forming then a “Centrifugal Magnetosphere” (CM), with density set at the critical level for “Centrifugal Breakout” (CBO) against the confining magnetic tension. This talk discusses how such CBO controls both the onset and strength of observed H-alpha emission, while the energetics of the associated CBO-driven magnetic reconnection match well the observed scalings of a non-thermal, circularly polarized radio emission from such stars .

Spectroscopic observations and modeling of solar flares: new insights from IRIS

Sede A. Riccò Via Santa Sofia 78, Catania

Recent high-resolution observations from the IRIS satellites have enabled significant advancements in our understanding of the physical mechanisms at play during the impulsive phase of flares, including details of how the non-thermal energy is released and propagated from the corona to the low-atmosphere through accelerated particles. At the same time, the new discoveries have brought to light new unsolved questions and challenges for current models. This talk will provide some examples of the unique contributions to our understanding of flares from IRIS, also in coordination with other solar observatories, and how state-of-the-art heating models of flares can be constrained by the available imaging and spectral diagnostics. I will also discuss some of the outstanding problems in preparation for the next generation of solar missions.

From clouds to fragments: on the multi-scale interplay between gravity and turbulence

Sede A. Riccò Via Santa Sofia 78, Catania

The star formation mechanism occurs in well defined structures that can be identified and studied in great details in our own Galaxy: the process starts in giant molecular clouds, objects extended up to several tens of parsecs, within which elongated sub-structures, called filaments, may form. Inside filaments, round-like condensations extended up to ~1pc in radius, the so-called clumps, are the natural birth site of the pre- and proto- stellar fragments, inside which will origin the future stars.
There are still many open questions in this hierarchical view of the star formation process: are these structures relatively confined from each other, or is the large-scale environment affecting the dynamics of the formation down to clumps and fragments? Is there a continuous interplay of the various forces involved in the process, namely turbulence, gravity (and magnetic fields), at all scales? Or is there a relevant scale at which gravity will start to dominate the collapse, with critical implications on the star-formation mechanism?
After a general overview of the problem, I will present in details some recent results focused on the interplay between gravity and turbulence at the filament, clump and fragment scales. To investigate this interplay at the larger scales, we have combined the dynamics of so-called 70 micron quiet clumps, i.e. very pristine regions not yet strongly affected by feedbacks, with the dynamics of the parent filaments in which they are embedded. At smaller scales, I will discuss the different scenarios of fragments formation in light of the most recent results from the SQUALO (Star formation in QUiescent And Luminous Objects) project. This ALMA survey has been designed to investigate the formation properties in a sample of massive clumps selected to be at various evolutionary stages and with the common feature that they are all accreting at the clump scales.
Our results show that a large scales we observe a continuous interplay between turbulence and gravity, where the former creates structures at all scales and the latter takes the lead above a critical value of the surface density is reached, ~ 0.1 g cm^-2. At the same time, the fragmentation properties show several indications that the fragment are "clump-fed", i.e. the process is dynamical and the gravity dominates the collapse inside our massive clumps.