The LIUniverse with Dr. Charles Liu

• Tiny Galaxies and Massive Black Holes with Dr. Matt Taylor

  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  

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• Black Holes Colliding with Dr. Charlotte Olsen

  How do very small galaxies form? What’s going on inside them? And what happens when black holes collide? To find out, Dr. Charles Liu and co-host Allen Liu welcome astrophysicist and “Galaxy Detective” Dr. Charlotte Olsen from New York City College of Technology – and you can call her Chuck, too! As always, though, we start off with the day’s joyfully cool cosmic thing, the latest announcement from LIGO about the detection of a gravitational wave event in 2023 from the loudest collision we’ve heard so far. In this case, the wave was caused by the collision of two black holes that created one new black hole about 60x the mass of our Sun and released an entire sun’s worth of energy. Charlotte explains why there are many black hole collisions going on, and how LIGO detections are now being combined with data from other gravitational wave detectors to give us more precise measurements. You’ll also hear about Active Galactic Nuclei (AGNs) and their negative impact on Charlotte’s research. Charlotte talks about what she looks for in her research, and why it all comes down to “wanting to see more photons” to better validate her modeling. Our first question from the audience comes from Joe, who asks, “What does it mean for the Milky Way to have a bar? Why does it have a bar? And how can such a long bar form?” It turns out that many spiral galaxies like ours have bars, and Charlotte explains a little about bar structure. She brings up the current debate about the stability of these bars, and points out that they actually come in slightly different configurations and that star formation at the ends of the bar has an impact, too. Unlike previous thinking, these bars can develop earlier in galactic evolution and can last a very long time. In other words, as Charlotte puts it, “The bar is always open.” Next, Chuck asks what got Charlotte into astronomy. She describes the inspiration she drew from both the dark skies of Northern California, where she grew up, and from the science fiction she read. She shares a few of her “million and one jobs” she did, including her stint as a bassist in a band. That tees up our next audience question, from Shivani, who asks, “How do you mix music and science? I can't decide if I want to be a scientist or a musician someday – can I be both?” Yes, Charlotte says, and explains why doing both might actually be better. She talks about the value of music, and passion, and hobbies that are more than just hobbies, as well as some of the live music she’s been seeing in Brooklyn, Long Island and Queens. Finally, Chuck asks Charlotte about the current passion project she’s working on. She tells us how she’s looking at a handful of galaxies in multiple wavelengths and comparing them to each other to figure out “what’s going on under the hood.” If you’d like to know more about Charlotte, you can connect with her on Bluesky at @charlotteeureka.bsky.social or on her GitHub page charlotteolsen.github.io. 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: Visualization of a binary black hole merger consistent with the gravitational-wave event called GW250114. (Note: this is to illustrate the collision of 2 black holes and the subsequent gravity waves generally, it is not specific to the GW230814 event Chuck mentions in the episode) – Credit: H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), K. Mitman (Cornell University) Animation of an active galactic nucleus. – Credit: NASA, ESA, and the Hubble SM4 ERO Team. Hubble Space Telescope image barred galaxy NGC 1300. – Credit: NASA, ESA, and The Hubble Heritage Team STScI/AURA Data from NASA's Wide-field Infrared Survey Explorer (WISE) used to trace the shape of the Milky Way's spiral arms. – Credit: NASA/JPL-Caltech #liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #charlotteolsen #blackholes #ligo #gravitationalwave #blackholecollisions #activegalacticnuclei #agns #milkyway #spiralgalaxies #barredgalaxies

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• Measuring the Stars with Astrostatistician Sabrina Berger

  How does a star form? How does the universe form? And how can we use every bit of astronomical data to answer those questions? To find out, Dr. Charles Liu and co-host Allen Liu welcome astrostatistician Sabrina Berger, all the way from Melbourne, Australia, where she’s currently pursuing her PhD. As always, though, we start off with the day’s joyfully cool cosmic thing, the new radioastronomy photographs of Callisto, one of the moons of Jupiter, taken by ALMA. Sabrina talks about her own low-frequency radio astronomy research looking for hydrogen in the very early reionization period of the universe when the first galaxies were forming. (Be warned: we dive into the difficulties ionization poses for trying to discern these early processes, including a side trip into quantum mechanics, the hyperfine transition of neutral hydrogen at 21cm depicted on the plaque attached to the Pioneer spacecraft, and even the Cosmic Background Radiation.) You’ll also hear how Sabrina is innovatively using GPS satellites to help calibrate large radioastronomy telescope arrays. For our first student question, Derek asks, “I heard that black holes can form right after the Big Bang, before stars do. How is that possible?” Sabrina describes these primordial black holes, and, although none have been confirmed yet, that there have been a number of papers published recently on the subject. In fact, one paper suggesting that the as-yet-undiscovered “Planet 9” could even be one of these primordial black holes. And then, finally, we get to the subject of astrostatistics, Sabrina’s area of expertise. She explains that it allows you to harness every piece of information that you’re observing in astronomy and to answer questions like “How does a star form?” or “How does the universe form?” You’ll hear about huge data sets, the use of artificial intelligence, field level inferences… and the MCMC, or the Markov chain Monte Carlo used in statistics. (If you don’t know what that is, you’re not alone, and our own resident mathematician Allen helps Sabrina untangle the complexity with a cotton ball analogy that blew Chuck and Sabrina’s collective minds!) For our next student question, Wally asks, “Why is redshift one like nine billion years ago, bur redshift two only two billion years before that, and redshift three only one billion years before that?” As Chuck says, “that’s a little complicated,” just before he, Allen and Sabrina proceed to explain how we measure universal expansion, the passage of time, and the “stretching” of light. Our next conversation is one of the most controversial we’ve ever had and revolves around who Sabrina thinks makes the best espresso, Australia, Italy or a “Third Wave Coffee Shop” like we have here in the US. You’ll hear about why there’s an ISSpresso machine on the ISS – and how the Italian Space Agency invented a way to make an espresso in zero-g! Plus, you’ll hear a little about the work-life balance in Australia and how wonderful astronomy down under is. (Check out our Patreon for the story behind the Australian Aboriginal "Emu-in-the-sky" constellation.) If you’d like to know more about Sabrina, you can find her on Twitter and Blue Sky @sabrinastronomy or check out her research on her website. 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: An image of Jupiter's icy moon Callisto, photographed by NASA’s Galileo spacecraft in 2001. – Credit: NASA/Galileo Photograph of Jupiter taken in 2019. The four fainter objects are four of its moons (left to right): Callisto, Ganymede, Io, and Europa. – Credit: Creative Commons / Rehman Abubakr ALMA images of Callisto – Credit: Maria Camarca et al 2025 Planet. Sci. J. 6 183. See the ALMA/Callisto paper: “A Multifrequency Global View of Callisto’s Thermal Properties from ALMA”: https://iopscience.iop.org/article/10.3847/PSJ/ade7ee Timeline of the universe. – Credit: NASA, ESA, CSA, STScI The Pioneer plaques, attached to the Pioneer 10 and 11 spacecraft. – Credit: NASA Sedna orbit with solar system (Sun, Jupiter, Saturn, Uranus, Neptune and Pluto visible) and positions on Jan 1, 2017 – Credit: Creative Commons / Tom Ruen Redshift and universe expansion. As light travels from great distances to Hubble's mirrors, it is stretched to longer and longer red wavelengths, or cosmologically redshifted, as the universe expands. – Credit: NASA, ESA, Leah Hustak (STScI) The ISSpresso machine on the International Space Station.– Credit: NASA Astronaut Samantha Cristoforetti drinking espresso out of the cup on ISS, 2015 – Credit: NASA #liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #sabrinaberger #astrostatistician #astrostatistics #redshift #blackholes #primordialblackholes #callisto #alma #planet9 #sedna #universeexpansion #isspresso

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• Cosmic Raspberries and Life on Mars with Dr. Kelly Blumenthal

  Have we discovered life on Mars? What does the center of our galaxy taste like? To find out, and to kick off Season 5 of The LIUniverse, Dr. Charles Liu and co-host Allen Liu have reached out all the way to Tokyo to chat with Dr. Kelly Blumenthal, the Director of the International Astronomical Union Office for Astronomy Outreach. As always, though, we start off with the day’s joyfully cool cosmic thing, a rock found in Sapphire Canyon by the Mars Perseverance Rover containing potential biosignatures. Allen explains why this rock is different: iron and sulfur nodules that exhibit indications of layers which, on Earth, could only be formed by bacteria. Kelly points out that there needs to be more investigation before we can say anything for sure. Chuck asks Kelly, who when she was 12 told her dad that she wanted to study galaxy evolution, to describe the research she did at the start of her career. She talks about studying with pioneering astronomer Joshua Barnes in Hawaii during her Masters projects and PhD. For her first project, she studied star formation rates in Jellyfish Galaxies, which are being ram-stripped of their gases and so appear to have tendrils. She ended up looking at the history of merging galaxies through cosmic time using large cosmological simulations. Then it’s time for our first student question of Season 5, from Jeannie, who asks, “Now that we’ve found so many planets outside of our solar system, should Pluto be promoted as a planet again?” (Pluto’s “demotion” nearly 20 years ago was traumatic for some.) According to Kelly, though, the “demotion” was really a reclassification, and at least for the time being, Pluto is going to stay a dwarf planet, a new category of which it was the first of its kind. She contrasts Pluto to the moons of Jupiter and reminds us of the new rules about what’s a planet and what’s not. Kelly brings up Star Trek and therefore gives Chuck permission to geek out over “Devil in the Dark” from the Star Trek: The Original Series, and “Silicon Avatar” from Star Trek: The Next Generation. Kelly talks about bingeing sci-fi in high school including 2001: A Space Odyssey, and the Foundation series, and more recently, The Expanse series, which she’s listened to three times as audio books! Chuck and Kelly discuss communicating about science, and even the role science fiction can play. Kelly talks about the importance of understanding your audience. She uses the example of explaining what nebulas look like through the Chandra X-Ray Observatory to a blind and low-vision audience. Kelly also talks about how you can approach science through poetry, music, dance, theatre and art – even smell. She recalls a talk where someone working with incarcerated kids, who was limited in what props they could bring, made the universe come alive for them using the scent of raspberries, which have a similar chemical signature as the center of our galaxy. For our next audience question, Bridget asks, “So is that comet actually an interstellar spaceship?” Kelly debunks the notion that Comet 3I/ATLAS is anything other than a rock that’s come from outside our solar system and explains why extrasolar asteroids are amazing things. We end with a discussion of the IAU’s upcoming, worldwide “100 Hours of Astronomy” on Oct. 2-5, 2025, including a 24-hour live stream on Oct. 4 from the oldest functioning planetarium in Japan. Watch it live on YouTube via the IAU Office for Astronomy Outreach @IAUoutreach here.  You can also visit their website at https://iauoutreach.org/, follow IAU Office for Astronomy Outreach on Facebook and LinkedIn, and on Instagram @oao_iau. If you have any questions, email them at [email protected]. You can follow Kelly on LinkedIn.  We hope you enjoy the Season 5 premiere of The LIUniverse. Please support us on Patreon. Credits for Images Used in this Episode: Observatory History Museum at NAOJ in Mitaka – Credit: おむこさん志望, CC BY 3.0 “Sapphire Canyon” sample – Credit: NASA Perseverance Rover Iron Bacteria in Scotland – Credit: Roger Griffith Jellyfish Galaxy ESO 137-001 – Credit: NASA/ESA/CXC Jellyfish Galaxy JO201 – Credit: ESA/Hubble & NASA, M. Gullieuszik, CC BY 4.0 New Horizons probe before launch – Credit: NASA Pluto’s “Heart”, Tombaugh Regio – Credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute Chandra X-ray Observatory (Illustration) – Credit: NASA/CXC/NGST Interstellar Comet 3I/Atlas – Credit: International Gemini Observatory/NOIRLab/NSF/AURA/Shadow the Scientist, CC BY 4.0 Artist’s illustration of interstellar asteroid 1I/'Oumuamua – Credit: NASA, ESA, Joseph Olmsted (STScI), Frank Summers (STScI) Interstellar Comet 2I/Borisov – Credit: NASA, ESA, and D. Jewitt (UCLA) 100 hours of Astronomy! – Credit: IAU, CC BY 4.0 #liuniverse #sciencepodcast #astronomypodcast #kellyblumenthal #lifeonmars #bacteria #jellyfishgalaxy #pluto #interstellarasteroid #comet3iatlas #iau #officeforastronomyoutreach #startrek #theoriginalseries #thenextgeneration #theexpanse

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• Chuck GPT Apocalypse, Part 2

  It’s the end of everything! Welcome back to Part 2 of our season finale featuring Dr. Charles Liu, co-host Allen Liu, and our guest archaeology expert and author, Hannah Liu, MEd. (If you haven’t caught up to Part 1, we highly recommend you do before embarking on the next leg of this journey! Listen here or wherever you get your podcasts!) We pick right up where we left off, with the next question from our audience. Daniela asks, “If a black hole hits the Sun, will Earth be destroyed?” Chuck explains a few ways a black hole can mess with our day, including the fact that long before any actual collision took place, the Sun would start shedding material that would destroy us. He compares that unlikely event to the actual example of cosmic destruction we’re watching in NGC 4676 – aka “The Mice” – which are two galaxies swirling together in a death spiral playing out over hundreds of millions of years. Naturally, this leads Chuck to ponder what happens when civilizations fall apart here on Earth, and Hannah brings up the collapse of the Roman Empire. As she explains, “the fall of Rome happened a lot of times, and also, no time.” From 44 BCE and the assassination of Julius Caesar, to the 476 invasion and conquest of Rome by the Germanic tribes denoted by Edward Gibbon in The History of the Decline and Fall of the Roman Empire, to the fact ever since nations have claimed to be the descendants or inheritors of Rome. Chuck points out the influence of Gibbon’s book on Isaac Asimov’s “Foundation” series, followed by a very quick romp through “Decline and Fall of America” literature including The Handmaid’s Tale, A Canticle for Liebowitz, Man in the High Castle, and the zombie apocalypse tour de force, World War Z. Then it’s time for another question from the audience: Michael says, “I heard that scientists brought back a dire wolf. Could they bring back dinosaurs or animals that could destroy us all?” It turns out, these resurrected animals are just gray wolves that have been engineered to have some characteristics of the extinct predator. It’s still a pretty impressive feat, though, and you’ll hear how they collected bits and pieces of dire wolf DNA to “resurrect them.” Allen also brings up similar modification experiments they’re doing on chickens to make them more dinosaur-like. Allen points out that bioengineered germs are far more likely to cause our destruction than resurrected dinosaurs, regardless of the world envisioned in the Jurassic Park franchise. And speaking of Michael Crichton, Chuck gives us a breakdown of his sci-fi classic, The Andromeda Strain, about bacteria from space that cause a biological outbreak here on Earth. Hannah points out that historically, some of the biggest killers of human beings have been plagues. She gives us a guided tour of the bubonic plagues, from the Black Death, which may have wiped out as much as 60% of the population of Europe, to the Plague of Justinian a thousand years earlier that killed as many as 100 million people, while also name dropping the Antonine Plague and the Spanish Flu!) And that’s it Season 4 of The LIUniverse. Stay tuned for Season 5 after the summer. If you want to find out more about what Hannah’s impending book, check out the Mixed Identity Project  We hope you enjoy this episode, and this season, of The LIUniverse. If you did, please support us on Patreon Credits for Images Used in this Episode: NGC 4676, aka “the Mice” are two galaxies swirling together.  – Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA; The ACS Science Team: H. Ford, G. Illingworth, M. Clampin, G. Hartig, T. Allen, K. Anderson, F. Bartko, N. Benitez, J. Blakeslee, R. Bouwens, T. Broadhurst, R. Brown, C. Burrows, D. Campbell, E. Cheng, N. Cross, P. Feldman, M. Franx, D. Golimowski, C. Gronwall, R. Kimble, J. Krist, M. Lesser, D. Magee, A. Martel, W. J. McCann, G. Meurer, G. Miley, M. Postman, P. Rosati, M. Sirianni, W. Sparks, P. Sullivan, H. Tran, Z. Tsvetanov, R. White, and R. Woodruff. Plaster replica of Statue of George Washington by Antonio Canova at the North Carolina Museum of History.– Credit: Creative Commons / RadioFan (talk) Dire Wolf Cover of TIME magazine, May 12, 2025. – Credit: TIME magazine Page Museum Display of 404 dire wolf skulls found in the La Brea Tar Pits. – Credit: Creative Commons / Pyry Matikainen The spread of the Black Death in Europe, 1346-1353. – Credit: Creative Commons / Flappiefh - Own work from: Natural Earth ; Cesana, D.; Benedictow O.J., Bianucci R. (2017). Yersinia pestis, the bacterium that causes the Plague. Direct Fluorescent Antibody Stain (DFA), 200x. – Credit: CDC 2057 - US Government public domain image, Courtesy of Larry Stauffer, Oregon State Public Health Laboratory Little Ice Age Temperature Chart. – Credit: Creative Commons / RCraig09 - Own work #liuniverse #charlesliu #allenliu #hannahliu #sciencepodcast #astronomypodcast #hannahliu #apocalypse #armageddon #doomsday #ngc4676 #themice #blackhole #romanempire #direwolf #bubonicplague #blackdeath #yersiniapestis #theandromedastrain #michaelcrichton #jurassicpark #littleiceage

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