Astronomy & Astrophysics Seminar: Mergers of neutron stars and black holes with cores of giant stars

Zoom: https://tau-ac-il.zoom.us/j/87230679135?pwd=Y1duRlArUkJwSnhaaXVscUU0azY3Zz09

Abstract:

The mergers of neutron stars (NSs) and black holes (BHs) with the cores of their giant secondaries during common envelope evolution can lead to luminous transient events that serve as progenitors of various high energy astrophysical phenomena. In this talk, I will focus on the production of heavy elements and the emission of high energy neutrinos from such mergers.

We study the formation of r-process elements in an accretion disk formed around a NS as it merges with the core of a red-supergiant (RSG).  We explore the feasibility of this nucleosynthesis channel by performing detailed stellar evolution simulations and find the accretion disk to be neutron-rich enough for r-process nucleosynthesis. We then estimate its contribution to heavy elements formation using binary population synthesis and galactic chemical evolution models and conclude that NS-core mergers might account for a substantial fraction of r-process nucleosynthesis in the Galaxy. Another high energy astrophysical phenomenon that can occur during a compact object-RSG common envelop evolution is the production of energetic neutrinos.  We study high energy neutrinos emission from relativistic jets launched by a BH prior to its merger with the core of a RSG, and find that such jets can accelerate cosmic rays to high enough energies to produce the PeV neutrinos detected by IceCube.
 

Seminar Organizer: Dr. Jonathan Stern

Recording of the Seminar >