Hunting for black hole binaries with gravitational waves
일 시 : 2020년 11월 30일 월요일 16:00
연 사 : 김 정 리 교수 (이화여자대학교 물리학과)
장 소 : 자연과학관 747호
The discovery of GW150914 showed some black holes do merge and the coalescence of a binary black hole (BBH) can be "directly observable" with gravitational waves (GWs). Although imaging is not possible with GW observation, masses of individual black holes in a binary can be measured by GW observation with impressive accuracy. With the mass and distance estimates of many BBHs, we can apply the 'standard siren' method to measure a Hubble constant , which was first suggested by Bernard Schutz in 1986. Stellar-mass BBHs are observable with km-scale laser interferometry in the GW frequency range of 10-2000 Hz. Supermassive BBHs would be observable by precision timing of millisecond radio pulsars at nano Hertz frequencies of GW signals. In this talk, I will give an overview on the second Gravitational-Wave Transient Catalog (GWTC-2) published in October, 2020 by the LIGO-Virgo collaboration. If time allows, I will try to briefly touch on the pulsar timing array and their expected constraints for GW background formed by superpositions of supermassive BBHs. Then, I will conclude with prospects for BH astrophysics and "GW cosmology" for the next decades.