Episode 120: Old Galaxies, New Problems

In this episode, Shashank and Cormac introduce our new ASB cohost Vivasvaan! Vivasvaan gives us a broad strokes overview of what galaxy mergers are and why astronomers love to study them while giving us a glimpse into his research involving galaxy mergers and machine learning. We also hear about some of the fun things Vivasvaan likes to do such as playing chess, and watching sports.

In this episode, Shashank, Cole and Cormac take a look at the periodic side of time-domain astronomy through the famed, fabled Fourier transform. Cole entreats us to the time lags in blazars and Cormac gives us a weather update on a brown dwarf. Along the way, we discuss some of the instruments, challenges and patterns in periodicity. Flashy and Fashionably Late: the Fascinating Time Lag in Blazar Flares: https://astrobites.org/2026/04/16/flashy-and-fashionably-late-the-fascinating-time-lag-in-blazar-flares/   How’s the Weather Looking on our Nearest Brown Dwarf Neighbors? https://astrobites.org/2026/03/13/hows-the-weather-looking-on-our-nearest-brown-dwarf-neighbors/   Space sound: https://www.youtube.com/watch?v=nBxn6QGWJNM

In this episode, we take a break from our usual astronomical antics to reflect on sustainability in the cosmos. Cormac, Cole and Shashank explore how the Universe manages to recycle material across all scales, from pepping up prostrated pulsars to cleaning up our orbital backyard. We conclude with a discussion of how analogies are (sometimes over)used in astronomy, and ponder when exactly a supernova remnant begins. Astrobites: Recycle your paper, plastic, and… pulsars? https://astrobites.org/2026/03/31/transitional_millisecond_pulsar The Final Frontier for the Circular Economy https://astrobites.org/2026/04/24/the-final-frontier-for-the-circular-economy Video about Swift boost mission: https://youtu.be/Up0LNTMPnjI

We’ve known about the existence of galaxies for about a hundred years, but how well do we actually know the extragalactic universe? In today’s episode, we dive deep on the earliest galaxies in the universe. Sanika covers her first bite on paradoxical galaxies that seem to be the deadest where we expect them to be alivest, and Shashank shows us a source of hidden mass in ancient galaxies that for once isn’t dark matter.    Astrobites:   The Walking Red: Why are you so quiet and overdense? https://astrobites.org/2026/04/03/walking-red/   Too Massive, Too Early… and Still Not Massive Enough? https://astrobites.org/2026/04/07/too-massive-too-early/   Space Sound: https://www.youtube.com/watch?v=4BPFHTVMmbQ

In this episode, we dive into the ripples of spacetime with a special focus on gravitational waves. Cole and Cormac are joined by a new host, Sanika, who introduces her research in gravitational wave astrophysics and sets the stage for the discussion. Together, they explore the role of neutron star and black hole mergers in producing gravitational waves, how we detect them, and what they reveal about some of the most extreme events in the universe. The conversation highlights major achievements from detectors like LIGO and Virgo, from the first historic detection to the growing catalog of binary mergers. Looking ahead, they discuss the exciting future of the field, including next-generation observatories and space-based missions like LISA. By the end, you’ll be tuned into the gravitational vibes shaping modern astrophysics. Fact sheet: https://ligo.org/detections/gw250114-10-years-of-gravitational-wave-astronomy/ Questions? [email protected] 

In this episode, as we (at the time of recording) approach Astronomy’s (JWST) awards season, Cormac and Cole shed some light on just how ideas become astronomical datasets. Our two putative principal investigators discuss why grad students should consider applying for telescope time, the main components and categories of proposals, and how successful proposals are finally selected and scheduled. We conclude with our most memorable moments from our own efforts to get time on facilities like JWST, Roman and Gemini. SPHEREx Data Tools: https://irsa.ipac.caltech.edu/applications/spherex/

In this episode, we move away from point particles to talk about fields. Shashank, Cole and Cormac start with a discussion of different kinds of fields in astrophysics. Then, Cole describes Lagrange points and why they can be useful for satellites and asteroids seeking a safe place to camp out (or lay siege). Cormac dives into the atmospheres of hot Jupiter exoplanets, where we get a glimpse of temperature and wind velocity fields on other planets. By the end, you’ll certainly have a lot more field experience!    What’s the (Lagrange) point? https://astrobites.org/2026/01/29/whats-the-lagrange-point/   The Fires Within: Investigating the Atmospheres of Inflated Hot Jupiters https://astrobites.org/2023/01/03/hot_interior_exoplanets/   Space sound:  https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Swarm/The_scary_sound_of_Earth_s_magnetic_field

  In our valentines’ day special, Shashank, Cole, and Cormac explore the dating lives of stars and other compact objects by looking at the romantic couples of astrophysics: binary systems. Immediately ruining this theme, Shashank covers some particularly messy breakups (though these lovers are able to rebound and move on) while Cormac shows us how even stars’ healthy relationships involve some give and take.   Astrobites:   What are Partial Tidal Disruption Events, and How Do We Find Them? https://astrobites.org/2025/08/04/partial-tdes-galactic-center/   Sharing is caring: how do binary stars actually transfer mass? https://astrobites.org/2025/07/14/binary-mass-transfer/   Space Sound: https://www.nasa.gov/missions/chandra/nasa-telescopes-tune-into-a-black-hole-prelude-fugue/

Apply to join us as a co-host! https://astrosoundbites.com/recruiting-2025 In today’s extra-special seasonal episode, Cormac, Lucia and Shashank share some of their highly curated metrics inspired by Spotify wrapped to end our a[s]b year. Much like ourselves, this episode is a mixed bag - we hope you enjoy it! This also marks the start of our long-awaited Winter (or Summer, depending on your hemisphere) break - see you in a few weeks! Space sound: https://www.youtube.com/watch?v=RmsOmqf7Hso Bonus festive EWOCS JWST image released after we recorded: https://esawebb.org/images/potm2512a/

Apply to join us as a co-host! https://astrosoundbites.com/recruiting-2025   This week, Shashank, Cole, and Cormac dive into the many disks of the universe, from planet-forming disks to AGN and galactic structures. Cole explores a misbehaving protoplanetary disk that hints at chaotic early planet formation. Cormac follows by showing how external radiation can erode disks and hinder the birth of giant planets. We then zoom out to compare these turbulent young systems to the massive disks around galaxies and supermassive black holes, tying together why disks form across so many cosmic environments and the methods we use to explore them.   Astrobites: https://astrobites.org/2025/09/18/forming-misaligned-discs/ https://astrobites.org/2025/11/01/planet_formation_vs_stellar_uv_radiation/   ALMA images: https://www.almaobservatory.org/en/press-releases/alma-campaign-provides-unprecedented-views-of-the-birth-of-planets/attachment/20181212-andrews-et-al-all-disks/ Space Sound: https://www.youtube.com/watch?v=8__1mSFS7vQ