Astro Seminar: Ataru Tanikawa

Date and Time: 24.03.2025 at 2:15 PM 

Speaker : Ataru Tanikawa (FPU)

Place : Auditorium A

Title: “Dynamical formation of compact binary systems discovered from Gaia DR3”

Abstract:

The Gaia mission and its follow-up observations have finally discovered compact binaries not involved in mass transfer, so-called Gaia Black Holes (BHs) and Gaia Neutron Stars (NSs). These compact binaries, which have orbital periods of more than 100 days, are completely new populations. These discoveries challenge the conventional binary evolution model. We have shown that open clusters can be promising formation sites of Gaia BHs. Moreover, we have found that a few percent of Gaia BHs may indeed harbor binary BHs. One binary BH will be present in Gaia BHs detected from Gaia DR4, since several tens of Gaia BHs will be detected in Gaia DR4. We will discuss how to discover such a binary BH among several tens of Gaia BHs.