The Secret Life of Black Widow Companions

QUEST Center event
No
Speaker
Sivan Ginzburg, Berkeley
Date
12/11/2020 - 20:30 - 19:00Add to Calendar 2020-11-12 19:00:00 2020-11-12 20:30:00 The Secret Life of Black Widow Companions Black Widows are rapidly spinning magnetized neutron stars with companions that are only a few percent the mass of the Sun. I will present numerical stellar evolution tracks showing how main sequence stars are reduced to such low masses by magnetic braking and Roche-lobe overflow. The numerical results are explained by an analytical model, similar to the Hayashi track, but accounting for the pulsar’s gamma-ray irradiation. I will compare the theory to radio and gamma-ray observations of the pulsars, as well as to novel optical images of the companions themselves. I will demonstrate that the mass at which a Black Widow companion becomes fully convective is a simple function of its orbital period, allowing us to study stellar structure and magnetism away from the main sequence in a controlled manner.  The seminar will be hosted on Zoom: https://zoom.us/j/9290951953 The talk's start time is 17:00 Jerusalem time, but we'll start gathering 30 minutes earlier for informal chat Zoom המחלקה לפיזיקה physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Zoom
Abstract

Black Widows are rapidly spinning magnetized neutron stars with companions that are only a few percent the mass of the Sun. I will present numerical stellar evolution tracks showing how main sequence stars are reduced to such low masses by magnetic braking and Roche-lobe overflow. The numerical results are explained by an analytical model, similar to the Hayashi track, but accounting for the pulsar’s gamma-ray irradiation. I will compare the theory to radio and gamma-ray observations of the pulsars, as well as to novel optical images of the companions themselves. I will demonstrate that the mass at which a Black Widow companion becomes fully convective is a simple function of its orbital period, allowing us to study stellar structure and magnetism away from the main sequence in a controlled manner. 

The seminar will be hosted on Zoom: https://zoom.us/j/9290951953

The talk's start time is 17:00 Jerusalem time, but we'll start gathering 30 minutes earlier for informal chat

תאריך עדכון אחרון : 13/10/2020