Descripción del proyecto
Nuevos conocimientos sobre la evolución estelar binaria
La evolución de envoltura común (CEE, por sus siglas en inglés) se refiere a una fase breve pero importante en la evolución de un sistema binario, en que dos estrellas interactúan fuertemente y pierden grandes cantidades de masa o se fusionan en un único objeto. Se prevé que la CEE esté acompañada por un aumento en la luminosidad representada como un evento transitorio rojo. Sin embargo, diversas características de estos eventos desafían al actual paradigma de la CEE. El proyecto Cat-In-hAT, financiado con fondos europeos, usará una nueva variante de magnetohidrodinámica para examinar las dinámicas tridimensionales de la CEE, desde el momento en que empieza la pérdida de masa hasta la fase remanente. Al evaluar las implicaciones para una amplia gama de objetos astrofísicos, el proyecto ofrecerá mayor información sobre este importante fenómeno.
Objetivo
"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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Ámbito científico
Palabras clave
Programa(s)
Régimen de financiación
ERC-STG - Starting GrantInstitución de acogida
116 36 Praha 1
Chequia