Compact object binaries in the galaxy and the resulting mass distributions

• Grant number: 25/01653-5
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: May 01, 2025
• End date: October 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Jorge Ernesto Horvath
• Grantee: Nathalia Aparecida Dutra Pires
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/16892-2 - Compact Star populations in the galaxy and the Cosmos, AP.R

Abstract

The determination of masses and number of compact objects in the galaxy is possible using traditional techniques based on Kepler's Laws, but also on new methodologies that have expanded the sample of neutron stars and black holes. These include Shapiro delay, spectrophotometry, microlensing and others. As a result, the masses of some 120 neutron stars (NSs) and 40 black holes (BNs) have been well measured. With this perspective, it is possible to study the existence of a series of problems, including the so-called mass gap, which is a mass interval marked by the absence of compact objects in the range of 2-5 Mo. Furthermore, one can research their relationship with production channels not yet quantitatively explored (such as spiders, Accretion-Induced Collapses, electron-capture supernovae and direct collapses without explosions) in order to identify the events and types of systems that produce compact objects and also ascertain the importance of "traditional" methods. The Plan proposes the use of the COMPAS synthesis code and the MESA stellar evolution code jointly in order to establish the characteristics of some important channels that are still little explored, and naturally, their effects on the mass distribution of compact objects and the mass gap. (AU)