Understanding cosmic explosions

summary

The gist

The gist: Millimeter-wavelength observations provide a uniquely sensitive window into the physics of cosmic explosions, from supernovae (SNe) and tidal disruption events (TDEs) to nova eruptions,

In short

Millimeter-wavelength observations are uniquely sensitive to cosmic explosions like supernovae and tidal disruption events, revealing physics at early shock interaction phases missed by traditional centimeter waves. ALMA2040 is essential because it can quantitatively answer key questions about the environment, energetics, absorption physics, and jet geometry in these extreme events.

Key concepts

Millimeter-wavelength observations: These observations use radio frequencies above the cm-wave domain to see physical processes in cosmic explosions. They are crucial because this frequency range allows scientists to separate thermal emission from non-thermal components and dust, which are often mixed together at lower frequencies.
ALMA2040 Capabilities: ALMA2040 is a next-generation facility designed to provide dramatically improved sensitivity, rapid spectral coverage, and polarimetry. These tools allow researchers to obtain robust physical constraints on transient events by resolving details about shock physics and magnetic fields that current facilities cannot yet capture.
Shock Microphysics: This refers to the physics governing how collisionless shocks (like those in cosmic explosions) affect particles. Scientists are trying to determine if the electron distribution and acceleration parameters are universal across different events or if they change over time, which helps understand how energy is transferred.
Environment Characterization: This involves determining the density, radial profile, and clumping of the surrounding gas near explosions. By observing how the early spectral peak evolves in millimeter waves, researchers can map out this structure to understand where and how these events occur.

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This episode discusses

The paper

Understanding cosmic explosions · Read on arXiv

Karri I. I. Koljonen, Tomek Kaminski, Anna Y. Q. Ho, Thomas Maccarone, Aneurin Evans, Mar´ıa D´ıaz Trigo, Thomas D. Russell, Dieu D. Nguyen, Dirk Petry, Jakob van den Eijnden, Tanmoy Laskar, Laura Chomiuk

Institut for Fysikk, Norwegian University of Science and Technology · Finnish Centre for Astronomy with ESO (FINCA) · Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences · Department of Astronomy, Cornell University · Department of Physics & Astronomy, Texas Tech University · Astrophysics Group, Lennard Jones Laboratory, Keele University · European Southern Observatory (ESO) · INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica · Department of Astronomy, University of Michigan · Anton Pannekoek Institute for Astronomy, Universiteit van Amsterdam · Department of Physics & Astronomy, University of Utah · Center for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University

Millimeter-wavelength observations provide a uniquely sensitive window into the physics of cosmic explosions, from supernovae (SNe) and tidal disruption events (TDEs) to nova eruptions, stellar mergers and electromagnetic counterparts to gravitational wave (GW) sources. Over the past decade, discoveries across the transient sky have revealed that many of the most informative phases of shock interaction, particle acceleration and jet formation unfold at frequencies above the traditional cm-wave domain, where synchrotron self-absorption weakens and thermal, nonthermal and dust components can be disentangled. Upcoming wide-field mm surveys will detect a new population of short-lived transients but will be limited by coarse localization and limited spectral characterization. ALMA2040, with dramatically improved sensitivity, wide instantaneous spectral coverage, rapid-response and sub-arraying modes, polarimetry and extended baselines, is essential for converting these discoveries into robust physical constraints. Here we outline the scientific context, key open questions and the ALMA2040 capabilities required to unlock the full potential of millimeter time-domain astrophysics in the 2040s.

Transcript

Introduction to the show: ident: Astrophysics Radio. Generated commentary on the latest astrophysics papers.

Vera: I'm Vera.

Jocelyn: And I'm Jocelyn, here with Subrahmanyan.

Vera: We're looking at the paper: "Understanding cosmic explosions".

Jocelyn: The gist: Millimeter-wavelength observations provide a uniquely sensitive window into the physics of cosmic explosions, from supernovae (SNe) and tidal disruption events (TDEs) to nova eruptions,

Vera: First, who's behind it and why it matters.

Paper summary: Jocelyn: We’ve talked about what this paper claims regarding how we can use mm wavelengths to probe shock microphysics and geometry across different classes of explosions, now we’re going to look at who wrote it and why it matters for the future.

Subrahmanyan: So what this means for the bigger picture is that we move beyond just seeing transients and start actually understanding the underlying physics of how these explosions operate in those extreme environments > It’s about connecting the dots between our observations and the fundamental physics of shock waves and relativistic outflows across all scales.

Conclusion: Vera: So we’ve covered how millimeter wavelengths let us peer into the very first moments of cosmic explosions, like supernovae and TDEs, where things are still happening before everything gets obscured by absorption or other effects.

Jocelyn: Yeah, and this paper, "Understanding cosmic explosions," is essentially arguing that we need these time-domain observations across millimeter wavelengths to get a consistent answer to the same fundamental physical questions about these diverse explosions.

Subrahmanyan: It’s connecting the dots between what we see in the sky now and how shock waves behave in those extreme environments, linking it all back to cosmology.

Vera: The authors are pointing out that this isn't just one type of explosion; it applies across a whole zoo of transients, from SNe to stellar mergers.

Jocelyn: And they’re calling for next-generation instruments like ALMA2040 to give us the uniform, quantitative answers we need to really map out this physics across all these different sources.

Subrahmanyan: So what this means for the bigger picture is that we move beyond just cataloging transients and start actually understanding the underlying physics of how these explosions operate in those extreme environments.

Vera: It’s about connecting the dots between our observations and the fundamental physics of shock waves and relativistic outflows across all scales.

Jocelyn: We’ve talked about what this paper claims regarding how we can use mm wavelengths to probe shock microphysics and geometry across different classes of explosions. Now we’re going to look at who wrote it and why it matters for the future.

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