Exploring the interplay between binaries and their host galaxies

by Dr Soheb Mandhai (University of Manchester)

Monday Oct 9, 2023, 11:00 AM → 12:00 PM Europe/Stockholm

Albano 3: 6335 - Hekto (10 seats) (Albano Building 3)

https://stockholmuniversity.zoom.us/j/530682073

 

There are many species of binaries that exist within the Universe - each offering unique insights and probes of stellar evolution and high energy astrophysics. However, isolating and finding these systems can be an ever-growing challenge, with some species of binaries eluding us completely. 

In this talk, I will explore the interactions between the host galaxies and binaries, to piece together their lives from birth to the present. To achieve this, the studies are conducted using simulations of galaxies from GADGET derivative simulations such as EAGLE (Schaye et al., 2015) and AURIGA (Grand et al., 2017), along with state-of-the-art stellar population synthesis codes such as BPASS v2.0+ (Eldridge et al., 2017) and COSMIC (Breivik et al., 2020). 

I will talk through the methods taken to seed binaries within their host galaxies and the approaches taken to trace their orbital dynamics, including brief discussions on galaxy mergers and the effects that these have. I will apply this framework to binaries from galactic and extra-galactic origin. 

 

For binaries of extra-galactic origin, we have been able to find consistencies with observed offsets of short-duration gamma-ray bursts using this method for double neutron star or neutron star - black hole binaries, to a first order. I will explore real world cases studies that we have conducted in an attempt to rationalise large offsets that we observe between transients and their host galaxies.

For binaries of galactic origin, we have built a more detailed framework (ongoing work) looking at the local stellar environments of binaries and tracing their orbits more precisely within the galaxy. The galaxy used for this work is analogous to the Milky Way but the framework can be extended to other morphologies in the future. I will talk about some of the ongoing work that we have been doing within the Spiders group at The University of Manchester, exploring the nature of millisecond pulsars and their low mass companion, and the benefits that the aforementioned framework provides to their understanding. 

In both cases, there is a motivation to use our findings to optimise search strategies of transient follow-up (e.g., EM counterpart follow-up of gravitational waves) or find high density regions to probe using future surveys and detectors. 

I welcome discussions and ideas of the themes covered in these works and potential avenues that would be of interest for different binaries and science cases.

Mandhai_2023-10-09.mp4