Séminaire Doctoral / Seminar PhD |
| « What role will binary neutron star merger afterglows play in multimessenger cosmology? » |
|
Raphaël Duque |
| Binary neutron star mergers offer a new and independent means of measuring the Hubble constant by combining the gravitational-wave-inferred source luminosity distance with its redshift obtained from electromagnetic follow-up. This method is limited by intrinsic degeneracy between the system distance and orbital inclination in the gravitational-wave signal. Observing the afterglow counterpart to a merger can further constrain the inclination angle, allowing this degeneracy to be partially lifted and improving the measurement of $H_0$. In the case of the binary neutron star merger GW170817, afterglow light-curve and imagery modeling thus allowed to improve the $H_0$ measurement by a factor of 3. However, systematic access to afterglow data is far from guaranteed. I will present models for emission and detection of gravitational-wave and electromagnetic radiation from binary neutron star mergers and realistic source population models. With these models, I will quantify whether afterglows will play a leading role in multimessenger cosmology, or whether they will be too rare to significantly contribute to the narrowing-down of the Hubble constant. |
|
vendredi 11 décembre 2020 - 17:00 Webinaire, Institut d'Astrophysique |
| Page web du séminaire / Seminar's webpage |