Intermediate mass black holes everywhere? – James Paynter

This is a high-level research talk designed for professional astronomers. It is part of the Caltech Astronomy Tea Talk Series, hour-long presentations given weekly by top scientists from around the world to the members of our department. All are welcome to watch these presentations; however, for talks specifically designed for the general public, please see our Caltech Astro Outreach channel: Timestamps and abstract are included below.

Date: 04/04/22
Speaker: James Paynter – University of Melbourne
Title: Intermediate mass black holes everywhere?
I present evidence for an intermediate mass black hole (IMBH) via a gravitationally lensed gamma-ray burst (GRB). In the first part of the talk I will speak about our detection methods, with the aim to convince you that our candidate is very much real. I will then speak about the lens itself, which being a few tens of thousands of solar masses and very compact is difficult to reconcile with anything but an IMBH. From here I estimate the cosmological density of such lenses, which rules out lensing by a globular cluster. Our estimated number density of 2000 per Megaparsec cubed is several orders of magnitudes above the current estimates for IMBH density. I then present more recent GRB lens candidates and update the estimated number density. I will also briefly speak about how lensing studies of radio candidates have found evidence for similar mass compact lenses. From here I collate work from many different authors to present how such a population could arise. I will also discuss our prospects for detecting these objects with eg. optical astronomy.

Source link

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button