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The LIUniverse with Dr. Charles LiuAuthor: theliuniverse
A half-hour dose of cosmic conversation with scientists, educators and students about the cosmos, scientific frontiers, scifi, comics, and more. Hosted by Dr. Charles Liu, PhD, an astrophysicist at the American Museum of Natural History. Support us on Patreon. Language: en Genres: Astronomy, Fiction, Science, Science Fiction Contact email: Get it Feed URL: Get it iTunes ID: Get it |
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Tiny Galaxies and Massive Black Holes with Dr. Matt Taylor
Episode 4
Saturday, 15 November, 2025
Can an ultra-compact dwarf galaxy have a supermassive black hole at its center? Are there galaxies with supermassive black holes that are offset from their galactic centers? To find out, Dr. Charles Liu and co-host Allen Liu welcome “the other” Dr. Matt Taylor, an Assistant Professor of Astronomy at the University of Calgary, who joins us from the control room of the largest astronomical telescope in Canada, at the Rothney Astrophysical Observatory (RAO) in Alberta, Canada. As always, though, we start off with the day’s joyfully cool cosmic thing, which starts with the discovery of a supermassive black hole in the middle of an ultra-compact dwarf galaxy M60-UCD1 located in the Virgo galaxy cluster. That led to the discovery of more 4 UCDs in the Virgo Galaxy Cluster and 1 in the Fornax galaxy clusters, but then the limits of technology prevented the discovery of any additional UCDs. But now, by using the James Webb Space Telescope, Matt and his fellow researchers (including Dr. Vivienne Baldassare, our former guest for Black Holes and Space Junk with Vivienne Baldassare) have just published a paper about their discovery that in the smallest, lowest mass UCD yet found, they found a roughly 2,000,000 solar mass black hole. Basically, that’s a tiny galaxy to hold a supermassive black hole, and Matt is sure there are many more of these waiting to be discovered. After that Matt tells us about his atypical journey to astronomy, including his first career – as a professional chef. When cooking stopped being fun, Matt enrolled at a local community college and “moved from gastronomy to astronomy” as Allen puts it. Our first audience question comes from our Patreon Patron Taylor L, who asks, “Is it possible dark energy and the acceleration of the universe's expansion could be explained by the idea that the black hole we live in is constantly devouring matter from outside?” Matt passes on determining whether or not we live inside a black hole. But, he explains that while at the galactic level expansion is happening on a really large scale, at a smaller scale like our local group of galaxies (Milky Way, Andromeda, and local dwarf galaxies), our mutual gravitation counteracts that expansion. Matt goes on to discuss how accretion disks are what makes it possible to “see” a black hole, but that ultra-compact dwarf galaxies don’t have gas and dust forming accretion disks. Instead, they use stellar velocities to find black holes in UCDs. Next up, Matt tells us about some of the research he’s doing into archetypal compact elliptical (cE) galaxies, which have the mass of a giant galaxy put into the volume of a dwarf galaxy, and how black holes appear in these systems. And Matt dangles another upcoming paper about galaxies with supermassive black holes that are offset from their galactic centers. For our next audience question, Pshemo asks: “We often say gravity is weak compared to other forces. But in the right regimes, like near black holes and neutron stars, or on large cosmic scales, it dominates every other interaction. Should we stop calling gravity a weak force?” It’s a thought-provoking question with an even better answer, so please watch or listen to the episode to hear it yourself from Matt. If you’d like to know more about Matt, you can check out his website, mataylor5128.github.io. (The 5128 comes from the famous and very cool galaxy NGC 5128, aka Centauras A) We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Virgo and Fornax galaxy clusters. – Credit: Creative Commons / Atlas of the Universe/ Richard Powell Southern portion of the Virgo Cluster as imaged by the Vera C. Rubin Observatory in very high resolution, taken on June 5, 2025. – Credit: RubinObs/NOIRLab/SLAC/NSF/DOE/AURA Ultra-compact galaxy M60-UCD1. – Credit: NASA, ESA, CXC, and J. Strader (Michigan State University) Diagram of a black hole accretion disk. – Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman Hubble image of Messier 32, an archetypal compact elliptical (cE) galaxy. – Credit: NASA/ESA Centaurus A (NGC 5128) – Credit: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray) #LIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast #MattTaylor #UltraCompactDwarfGalaxy #UDC #SupermassiveBlackHole #BlackHole #AccretionDisk #M60UCD1 #ArchetypalCompactEllipticalGalaxy #UltraCompactGalaxy
