Dr Nandini Sahu: Weighing black holes and dark matter, Wednesday 2 October, 6:30pm

Presented on-line via zoom

Title: Weighing black holes and dark matter

Credit: NASA/ESO

The supermassive black hole that resides at the center of a galaxy is expected to co-evolve with the host galaxy. An evidence of this co-evolution is the relation observed between supermassive black hole mass and the host galaxy properties. I will talk about the relationship between supermassive black holes and their host galaxy, which we discovered during my PhD. These relations are used to estimate the mass of the black holes at the centers of other distant galaxies, so far that our current telescopes can not resolve the stars around the black hole.

I will also talk about a naturally occurring phenomenon called gravitational lensing, which has become a powerful tool for astronomers to measure dark matter. Dark matter is invisible but has a mass and constitutes most of the matter in the Universe. I will talk about how we use gravitational lensing observations to measure total mass, including luminous and dark matter in galaxies, and try to understand the role of dark matter in shaping the galaxies we observe.

Bio

I am an ASTRO3D Postdoctoral Fellow at the University of New South Wales, Sydney, Australia working as a part of the Astro3D Galaxy Evolution with Lenses (AGEL) collaboration. I am currently modeling high redshift gravitational lenses and using lens modelling results to understand the galaxy evolution models. Before joining UNSW,

I completed my PhD at the Centre for Astrophysics and Supercomputing (CAS), Swinburne University of Technology (SUT), Melbourne, Australia, in 2021. This was followed by a short-term postdoctoral researcher position between September 2021 to May 2022. My PhD thesis titled "Morphology-dependent Black Hole Mass Scaling Relations" presents the investigation of correlation between black hole mass and various host galaxy properties obtained using state-of-the-art two-dimensional modelling and multi-component decomposition technique.

Details: This presentation will be by Zoom. Members will be emailed the Zoom link. If you are not a member and want to attend this talk please email our secretary on: sydneycityskywatchers@gmail.com.

Prior to the keynote which commences at 6:50pm there are short presentations by members.