Astro Seminar: Christopher Tiede

Title: Active galactic binaries: Evolution and observational signatures of accreting massive binaries in the era of multi-messenger astrophysics

Speaker: Christopher Tiede (NBI)

Date and time: 18.11.2024 at 2:15 PM

Abstract: The final phases of the massive binary life-cycle, from galaxy merger to gravitational wave driven coalescence, remain a mystery in modern astrophysics. Many of these systems—like their single black hole AGN counterparts—are expected to evolve through periods of gas accretion. The presence of gas around a compact, massive binary will not only meaningfully impact the evolution of the binary’s orbit, but can also back react on the gas to create distinct electromagnetic signatures. Recent works have demonstrated sensitivities to numerous parameters like the intrinsic binary orbital elements as well as the thermodynamic and geometric assumptions about the surrounding disk. These can imprint on the full population of massive binaries and the observational features of individual sources. I will present recent analytic and hydrodynamics simulation work exploring the evolution and variability signatures of accreting binaries with a particular focus on the effects of binary eccentricity and disk geometry. I will also discuss how we can apply these results to inform current and future observing campaigns in both electromagnetic waves with large-scale surveys like LSST as well as in gravitational waves with PTAs and the upcoming LISA satellites.

Place: Auditorium A, Blegdamsvej 17