Multi-messenger astrophysics

Astro-COLIBRI
  • 5.0 (1)
  • Astronomy
  • Updated Weekly

Discussions around tools and discoveries in the novel domain of multi-messenger and time domain astrophysics. We'll highlight recent publications, discuss tools to faciliate observations and generally talk about the cool science behind the most violent explosions in the universe.

  1. 2d ago

    GUANO, NITRATES, and GLIMPSE: The Pipelines Powering Multi-Messenger Astronomy

    In this episode, we dive into the cutting-edge of time-domain and multi-messenger astrophysics with a deep look at BAT-GLIMPSE, a revolutionary new open-source pipeline developed for the Neil Gehrels Swift Observatory. Historically, Swift's Burst Alert Telescope (BAT) suffered from a critical blind spot: its onboard triggering capability is intentionally disabled whenever the spacecraft is slewing (moving between targets) to prevent false alarms. With the observatory taking on more Target of Opportunity observations, the spacecraft spends more time slewing, reducing its chance to serendipitously catch Gamma-Ray Bursts (GRBs). Enter BAT-GLIMPSE (Gamma-ray Localization using Imaging and Mosaic techniques for Pointing and Slew Epochs). We explore how this fully autonomous system uses advanced coded-mask imaging and mosaic techniques to recover arcminute positions of high-energy transients even while the telescope is in motion. We also break down how GLIMPSE works in perfect synergy with two other powerful ground-based systems: GUANO (Gamma-Ray Urgent Archiver for Novel Opportunities): An automated infrastructure that commands on-demand downlinks of time-tagged event (TTE) data around external triggers.NITRATES (Non-Imaging Transient Reconstruction and Temporal Search): A highly sensitive, likelihood-based pipeline that hunts for faint, sub-threshold GRBs. While extremely powerful, NITRATES is limited to periods when the spacecraft is in a stable, stationary pointing mode. By seamlessly filling the gap left by slew intervals, BAT-GLIMPSE and NITRATES together are estimated to double the onboard arcminute-localization rate of Swift-BAT. We'll also discuss the real-world impact of GLIMPSE during the fourth LIGO-Virgo-KAGRA (LVK) observing run, where it operated in extreme low-latency to hunt for gamma-ray counterparts to gravitational waves—specifically in response to pre-merger alerts through the ULTRA-Swift project. Reference Article: Ronchini, S., Parsotan, T., DeLaunay, J., & Kennea, J. A. (2026). Swift gives a new BAT-GLIMPSE: Gamma-ray Localization using Imaging and Mosaic techniques for Pointing and Slew Epochs. Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: Spectrum Astro

    GUANO, NITRATES, and GLIMPSE: The Pipelines Powering Multi-Messenger Astronomy

  2. Jul 13

    The Dynamic Radio Sky: Unveiling Transients with the SKAO

    Welcome to a deep dive into the fast-paced, explosive universe of time-domain astronomy! In this episode, we explore how the upcoming Square Kilometre Array Observatory (SKAO) will revolutionize our understanding of astrophysical transients. Operating across a massive discovery space—from coherent radio bursts lasting just microseconds to the decades-long afterglows of cosmic collisions—radio transients serve as natural laboratories for fundamental physics. We discuss the diverse menagerie of extreme events SKAO will uncover and how new automated technologies will capture the universe in action. Key Topics Discussed: Fast Radio Bursts (FRBs) & Long-Period Transients (LPTs): We explore the extremes of coherent radio emission. Discover how SKAO will track millisecond-duration extragalactic FRBs across broad frequency ranges and unveil the nature of a newly discovered class of sources—Long-Period Transients (LPTs)—which emit periodic radio bursts lasting minutes to hours and may be powered by highly-magnetized white dwarf binaries or magnetars. The Multi-Messenger Era: We unpack the synergies between SKAO and next-generation multi-messenger observatories. Learn how SKAO will hunt for the radio afterglows of binary neutron star mergers detected by 3G gravitational wave detectors, and how it will survey the localization fields of high-energy neutrinos detected by IceCube and KM3NeT to find their elusive point sources.Gamma-Ray Synergies with CTAO: A look at how SKAO will collaborate with the upcoming Cherenkov Telescope Array Observatory (CTAO). By combining radio and very-high-energy gamma-ray data, astronomers will probe particle acceleration and shocks in extreme environments, including supernovae, X-ray binaries, novae, and tidal disruption events (TDEs).Rapid-Response Triggering & Commensal Surveys: How do you catch a flash you didn't know was coming? We delve into the cutting-edge operational modes of the SKAO, including "rapid-response" systems that will automatically repoint the telescope in seconds based on automated alerts (like VOEvents). We also cover "commensal" transient pipelines, which hitch a ride on other dedicated observations to continuously search for unexpected transients in the image plane without requiring extra telescope time. References (Chapters in Advancing Astrophysics with the SKA – II): Anderson, G. E., et al. Rapid Response Triggering for Radio Transients with the SKA Observatory.Andersson, A., et al. Commensal image plane transient search methods with the SKAO.Caleb, M., Qiu, H., et al. Long-Period Transients as a new frontier in time-domain astronomy.Castignani, G., Rowell, G., et al. SKAO and Gamma-Ray Synergies.Colombo, A., et al. Gamma-ray Bursts and Kilonovae from Gravitational Wave Events.Curtin, A. P., et al. The Astrophysics of Fast Radio Bursts.Miller-Jones, J. C. A., et al. Unveiling Radio Transients with SKAO Telescopes.Rösch, F., et al. A Census of Variable and Transient Radio Sources Within High-Energy Neutrino Fields. Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: SKAO

    The Dynamic Radio Sky: Unveiling Transients with the SKAO

  3. Jul 8

    X-Raying the Earth: Neutrino Tomography at the South Pole

    Welcome back to the podcast! Today, we are exploring a groundbreaking new way scientists are looking deep inside our planet. For a century, our understanding of the Earth's interior has relied almost entirely on seismic waves and gravity. But what if we could use cosmic "ghost particles" to scan the Earth instead? In this episode, we dive into a fascinating new study from the IceCube Neutrino Observatory located deep in the glacial ice at the South Pole. Using 10.7 years of data, scientists have successfully mapped the Earth's radial density profile using high-energy muon neutrinos. We discuss how these neutrinos, which usually pass right through matter undetected, become partially blocked by the Earth at extremely high energies (above ~10 TeV). By measuring how these particles are absorbed as they travel through different layers of the planet at different angles, researchers can essentially take a tomographic scan of the Earth's interior using the weak nuclear force. Tune in to hear how this cutting-edge method has been used to independently calculate the Earth's mass and polar moment of inertia, yielding results that are completely consistent with traditional seismology and the Preliminary Reference Earth Model (PREM). We also discuss what this means for the future of planetary science and how next-generation neutrino telescopes will bring even sharper resolution to the hidden layers beneath our feet. Reference mentioned in this episode: Abbasi, R., et al. (IceCube Collaboration). "High-Energy Neutrino Tomography of the Earth’s Interior with IceCube." arXiv:2607.02644v1 (July 2026). Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: IceCube Collaboration

    X-Raying the Earth: Neutrino Tomography at the South Pole

  4. Jul 6

    SVOM's First Year: From Gamma-Ray Bursts to Blazars

    In this episode, we dive into the exciting early results from the SVOM (Space-based multi-band astronomical Variable Objects Monitor) mission, which launched in June 2024. Originally designed to hunt for Gamma-Ray Bursts (GRBs), SVOM has proven to be a highly versatile powerhouse for all kinds of high-energy transient phenomena. We discuss its first batch of discoveries, from ancient stellar explosions at the edge of the universe to the serendipitous detections of black holes, flaring stars, and active galaxies! Key Topics Discussed: The Hunt for GRBs: We look at how SVOM successfully detected 86 GRBs in its first 9.3 months. We explore how its ECLAIRs and Gamma-Ray Monitor (GRM) instruments work together to capture everything from classical long GRBs to soft X-ray flashes and short GRBs tied to neutron star mergers. Probing the Distant Universe: A special spotlight on GRB250314A, a massive star explosion detected at a redshift of roughly 7.3. This incredible detection allows astronomers to peer back into the universe's epoch of reionization.The Observatory Science Program: We explore SVOM's secondary objective, which focuses on tracking non-GRB events. This program has already yielded hundreds of detections, primarily consisting of low-mass and high-mass X-ray binaries.Serendipitous Discoveries: Hear about SVOM's fascinating unexpected catches, like an X-ray outburst from the blazar 1ES 1959+650, burst oscillations from the neutron star binary 4U 0614+091, and even hard X-ray stellar flares from the binary star system HD 22468.Multi-Wavelength Synergy: We discuss how SVOM's onboard suite of instruments—which include wide-field coded-mask imagers and narrow-field X-ray and visible telescopes—work together. We also touch on how SVOM collaborates with other observatories like Swift and Einstein Probe to provide a rapid, comprehensive view of the high-energy sky. References / Mentioned Articles: Daigne, F., et al. (2026). First Gamma-Ray Burst Observations with SVOM. Research in Astronomy and Astrophysics. Coleiro, A., et al. (2026). Early results from the SVOM Observatory Science program. Research in Astronomy and Astrophysics.Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: CNES

    SVOM's First Year: From Gamma-Ray Bursts to Blazars

  5. Jul 3

    SN 2024jlc: Bridging the Gap Between Supernova Classes

    In this episode, we dive into the fascinating discovery of SN 2024jlc, one of the closest and least luminous super-luminous supernovae (SLSNe) ever found. We explore how this extraordinary event is challenging our understanding of stellar explosions by serving as a "bridge" between classic stripped-envelope supernovae (SE-SNe) and their super-luminous cousins. We unpack the massive multi-wavelength campaign used to study it—spanning from ultraviolet and optical light to X-rays and even high-energy gamma-rays. Key Topics Covered: Defying Classification: Why SN 2024jlc's exceptionally low peak luminosity and rare helium signatures make it a unique SLSN-Ib, defying standard stellar explosion models.The Powering Engine Debate: What is driving this massive explosion? We discuss the two leading theories: the radioactive decay and interaction with a circumstellar medium (CSM) versus the spin-down of a rapidly rotating young magnetar. Whispers of Gamma-Rays: We look at the intriguing, tentative hint of a gamma-ray signal picked up by the Fermi-LAT space telescope, and what it might mean for the hidden central engine powering the supernova.The Future of Supernova Hunting: How upcoming surveys like the Vera C. Rubin Observatory's LSST will help uncover more of these "missing link" transitional objects in the cosmos. Article Reference Discussed in this Episode: Simongini, A., et al. (2026). Bridging the gap between SLSNe and SE-SNe: Multi-wavelength analysis of the SLSN-Ib SN 2024jlc. Astronomy & Astrophysics. Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: NASA

    SN 2024jlc: Bridging the Gap Between Supernova Classes

  6. Jun 26

    Cosmic Accelerators: Unlocking the Secrets of Microquasar GRS 1915+105

    In this episode, we dive into the extreme and fascinating world of microquasars—binary systems where a compact object, like a black hole, feeds off a companion star and launches powerful, relativistic jets. Our spotlight is on GRS 1915+105, one of the most dynamic and powerful microquasars known in the Milky Way. Recent groundbreaking observations from the LHAASO and Fermi-LAT observatories have mapped broadband gamma-ray emissions from this system, revealing that it operates as an extreme "PeVatron"—an accelerator capable of pushing particles to multi-PeV (peta-electron volt) energies. We break down the evidence pointing to a "hadronic scenario," which suggests that these mind-boggling energies are produced when highly accelerated protons from the jet smash into the dense ambient gas surrounding the system. Join us as we discuss how this discovery proves that microquasars are exceptionally efficient particle accelerators and how they might be the missing link to understanding the origins of the most energetic cosmic rays in our galaxy. Key Takeaways: What is a Microquasar? A look at the anatomy of GRS 1915+105, a system featuring a black hole pulling material from a small K-type star and firing off jets at 80% the speed of light.The Power of LHAASO & Fermi-LAT: How a joint analysis of 4 years of LHAASO data and 17 years of Fermi-LAT data finally detected persistent gamma-ray emissions from this source.The Hadronic Accelerator: Why the shifted centroid of the gamma-ray emission suggests that protons (rather than electrons) are being accelerated by the jet's mechanical power and colliding with surrounding interstellar gas. Solving a Galactic Mystery: How just a handful of microquasars like GRS 1915+105 could be responsible for supplying the entire Milky Way with PeV-level cosmic rays. Reference: Cao, Z., Aharonian, F., Bai, Y.X., et al. (The LHAASO Collaboration). "Extreme PeV accelerator associated with GRS 1915+105." (Preprint: 2606.25054v1). Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: NASA/CXC/A.Hobart

    Cosmic Accelerators: Unlocking the Secrets of Microquasar GRS 1915+105

  7. Jun 22

    Echoes of Annihilation: Solving the 10 MeV Mystery of GRB 221009A

    In this episode, we dive into the fascinating astrophysics surrounding GRB 221009A, the brightest gamma-ray burst observed to date. While its sheer energy is staggering, we focus on an even more intriguing puzzle: an unprecedented, narrow emission line at around 10 MeV discovered shortly after the burst's brightest peak. We explore a groundbreaking new study that explains this 10 MeV line as the result of a massive annihilation of electron-positron pairs. We break down the proposed scenario in which the GRB's precursor blastwave was illuminated by the burst's main event, triggering copious pair creation that resulted in a "pair bubble bursting". Because this annihilation happened so quickly as the shell expanded relativistically, the resulting line evolution is dominated by what astrophysicists call the high-latitude emission (HLE) effect. Furthermore, we examine what this means for the actual star that caused the burst. To make this model work, the progenitor star must have been surrounded by an incredibly dense circum-stellar medium (CSM) extending out to a few $10^{15}$ cm, reminiscent of the dense environments found around Type IIn supernovae. Finally, we'll connect these findings to the sharp rise in the TeV afterglow observed by the LHAASO observatory, which the researchers attribute to the main ejecta colliding with this pair-enriched blastwave. Key Takeaways: The 10 MeV Emission Line: How high-latitude emission from a geometrically thin, relativistically expanding shell explains this rare spectral feature.Pair Production and Annihilation: The mechanism where gamma-rays from the main event interact with a precursor blastwave to create extreme numbers of electron-positron pairs.Clues About the Progenitor Star: Why the presence of a dense circum-stellar medium suggests the dying star underwent an intense mass-loss phase in the years just prior to its explosion.Solving the LHAASO Afterglow Mystery: How the collision between the main event ejecta and the pair-loaded blastwave perfectly accounts for the sudden, sharp rise in the TeV afterglow. Episode Reference: Salafia, O. S., Celotti, A., Sobacchi, E., Nava, L., Oganesyan, G., Ghirlanda, G., Boula, S., Ravasio, M. E., & Ghisellini, G. (2026). A self-consistent explanation of the MeV line in GRB 221009A unveils a dense circum-stellar medium. Astronomy & Astrophysics. Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: Jingchuan Yu

    Echoes of Annihilation: Solving the 10 MeV Mystery of GRB 221009A

  8. Jun 16

    Decoding the BOAT: GRB 221009A and the Hunt for High-Energy Neutrinos

    In this episode, we dive into the astrophysics behind GRB 221009A, an event widely known as the Brightest-Of-All-Time (BOAT) gamma-ray burst. Detected in October 2022, this extraordinary explosion shattered records by producing ultra-high-energy photons exceeding 10 TeV. We discuss a recent multi-messenger study that models the burst's very-high-energy (VHE) afterglow using a Gaussian structured jet expanding into an interstellar medium. We explore how this smooth, angular jet structure explains the extreme TeV output observed at a mildly off-axis viewing angle, cleanly resolving the "energy crisis" that standard uniform (top-hat) jet models face. Finally, we tackle the mystery of the missing neutrinos. Despite the immense energy of the BOAT, observatories like IceCube have not detected any coincident neutrinos. We break down the calculations for photo-hadronic ($p\gamma$) neutrino production and explain why the expected flux still falls below the sensitivity limits of even the next generation of detectors, like IceCube Gen2 and GRAND200k. Key Takeaways: The BOAT GRB: GRB 221009A was a remarkably luminous and relatively nearby event, offering an unprecedented opportunity to test emission models and ultra-high-energy cosmic ray acceleration.The Power of a Gaussian Jet: By using a Gaussian structured jet model, scientists can accurately reproduce the burst's gradual light curve steepening and immense brightness without requiring physically unrealistic energy budgets. A Mildly Off-Axis View: The study reveals that the optimal way to interpret the data is a mildly off-axis viewing geometry, which allows the observer to receive intense early-time emission from the jet's core.Neutrino Non-Detection Explained: Mathematical models of the photo-pion decay channel show that even under highly optimistic microphysical parameters, the predicted muon neutrino events remain below current and future detection limits, confirming that the null results from IceCube are consistent with the physics. Reference to the Article Discussed: Mondal, T., Razzaque, S., Joshi, J. C., Majumder, S., & Bose, D. (2026). Multi messenger study of GRB 221009A with VHE gamma-ray and neutrino Afterglow from a Gaussian structured jet. Journal of High Energy Astrophysics, 53, 100636. Acknowledements: Podcast prepared with Google/NotebookLM. Illustration credits: NASA's Goddard Space Flight Center and Adam Goldstein (USRA)

    Decoding the BOAT: GRB 221009A and the Hunt for High-Energy Neutrinos
See All (110)

About

Discussions around tools and discoveries in the novel domain of multi-messenger and time domain astrophysics. We'll highlight recent publications, discuss tools to faciliate observations and generally talk about the cool science behind the most violent explosions in the universe.

Information

You Might Also Like