Descrizione del progetto
Nuove prospettive sull’evoluzione delle stelle binarie
Con l’espressione evoluzione dell’involucro comune si fa riferimento a una fase breve, ma importante, nell’evoluzione di un sistema binario, in cui due stelle interagiscono fortemente e perdono enormi quantità di massa oppure si fondono in un oggetto singolo. L’evoluzione dell’involucro comune dovrebbe essere accompagnata da un aumento nella luminosità rappresentato come un evento di transiente rosso. Tuttavia, diverse caratteristiche del transiente rosso mettono in discussione l’attuale paradigma dell’evoluzione dell’involucro comune. Il progetto Cat-In-hAT, finanziato dall’UE, impiegherà una nuova variante di magnetoidrodinamica per esaminare la dinamica tridimensionale dell’evoluzione dell’involucro comune dal momento in cui ha inizio la perdita di massa fino alla fase del resto. Attraverso la considerazione delle implicazioni per un’ampia gamma di oggetti astrofisici, il progetto fornirà ulteriori informazioni relative a questo importante fenomeno.
Obiettivo
"One of the crucial formation channels of compact object binaries, including sources of gravitational waves, critically depends on catastrophic binary interactions accompanied by the loss of mass, angular momentum, and energy (""common envelope"" evolution - CEE). Despite its importance, CEE is perhaps the least understood major phase of binary star evolution and progress in this area is urgently needed to interpret observations from the new facilities (gravitational wave detectors, time-domain surveys).
Recently, the dynamical phase of the CEE has been associated with a class of transient brightenings exhibiting slow expansion velocities and copious formation of dust and molecules (red transients - RT). A number of RT features, especially the long timescale of mass loss, challenge the existing CEE paradigm.
Motivated by RT, I will use a new variant of magnetohydrodynamics to comprehensively examine the 3D evolution of CEE from the moment when the mass loss commences to the remnant phase. I expect to resolve the long timescales observed in RT, characterize binary stability in 3D with detailed microphysics, illuminate the fundamental problem of how is orbital energy used to unbind the common envelope in a regime that was inaccessible before, and break new ground on the amplification of magnetic fields during CEE.
I will establish RT as an entirely new probe of the CEE physics by comparing my detailed theoretical predictions of light curves from different viewing angles, spectra, line profiles, and polarimetric signatures with observations of RT. I will accomplish this by coupling multi-dimensional moving mesh hydrodynamics with radiation, dust formation, and chemical reactions. Finally, I will examine the physical processes in RT remnants on timescales of years to centuries after the outburst to connect RT with the proposed merger products and to identify them in time-domain surveys.
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Campo scientifico
Parole chiave
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-STG - Starting GrantIstituzione ospitante
116 36 Praha 1
Cechia