RSN1: Unveiling the origin of first supermassive black holes with gravitational wave signatures

Dettagli
Venerdì, 22 Luglio 2022 00:16

Dottorato - Phd Thesis

Area Tematica: RSN 1 - Galassie e cosmologia

Referenti: Gabriella De Lucia (Questo indirizzo email è protetto dagli spambots. È necessario abilitare JavaScript per vederlo.), Michaela Hirschmann (Questo indirizzo email è protetto dagli spambots. È necessario abilitare JavaScript per vederlo.)
Titolo: Unveiling the origin of first supermassive black holes with gravitational wave signatures
Decorrenza: 07.07.2022

Supermassive black holes (SMBHs) have been directly and indirectly observed at the centre of galaxies, including our own Milky Way. Recent observations of quasars at early cosmic epochs (z>7) suggest that SMBHs with mass larger than  ~10^9 Msun formed very early in the history of the Universe, and built their mass over just few hundreds of Myrs from the Big Bang. How these BHs are `seeded' and grow remains largely an open question. Next-generation gravitational wave experiments (Einstein Telescope, LISA) will provide powerful means to distinguish different BH seeding and formation scenarios by detecting BH mergers and binaries. The Square Kilometer Array, the James Webb Space Telescope, and the next generation X-ray missions like Athena and Lynx will also provide new information on the earliest accreting BHs.

The proposed PhD project is focused on the development and implementation of different BH seeding models in the modern GAEA semi-analytic framework.  The recently developed GAEA model (Hirschmann, De Lucia & Fontanot 2016) represents an ideal tool to carry out this investigation, thanks to the improved modelling of gas accretion onto BHs and their feedback processes (Fontanot et al. 2020). GAEA will be applied to merger trees extracted from high-resolution N-body simulations and/or constructed with the fast code PINOCCHIO (Monaco et al. 2013), and will be extended by explicitly following the merger time-scales of BHs using results from detailed high-resolution merger simulations that include a post-newtonian treatment.  This will allow us to make direct predictions for up-coming gravitational wave experiments.  Ultimately, a comparison between our model predictions and observational measurements that will be obtained in the future, will put strong constraints on the adopted seeding models.
 
The PhD student is expected to gain insight in several forefront astrophysical topics with steadily increasing interest:  supermassive black hole physics, gravitational wave astronomy and numerical galaxy formation.

Other people who will be involved in the project include: F. Fontanot and P. Monaco. There will be interactions with researchers actively involved in GW astronomy, both in the local area (e.g. E. Barausse, SISSA) and based in other institutes.