Core-Collapse Supernovae, Neutrinos, and Gravitational Waves (1212.4250v1)

Abstract: Core-collapse supernovae are among the most energetic cosmic cataclysms. They are prodigious emitters of neutrinos and quite likely strong galactic sources of gravitational waves. Observation of both neutrinos and gravitational waves from the next galactic or near extragalactic core-collapse supernova will yield a wealth of information on the explosion mechanism, but also on the structure and angular momentum of the progenitor star, and on aspects of fundamental physics such as the equation of state of nuclear matter at high densities and low entropies. In this contribution to the proceedings of the Neutrino 2012 conference, we summarize recent progress made in the theoretical understanding and modeling of core-collapse supernovae. In this, our emphasis is on multi-dimensional processes involved in the explosion mechanism such as neutrino-driven convection and the standing accretion shock instability. As an example of how supernova neutrinos can be used to probe fundamental physics, we discuss how the rise time of the electron antineutrino flux observed in detectors can be used to probe the neutrino mass hierarchy. Finally, we lay out aspects of the neutrino and gravitational-wave signature of core-collapse supernovae and discuss the power of combined analysis of neutrino and gravitational wave data from the next galactic core-collapse supernova.

• The paper demonstrates that multidimensional neutrino-driven instabilities and SASI are key to realistic supernova explosion models.
• It reveals how the rise time of electron antineutrino flux can help determine the neutrino mass hierarchy using detectors like IceCube.
• It proposes that gravitational wave signatures from CCSNe can be exploited to refine models of stellar core dynamics and the nuclear equation of state.

Core-Collapse Supernovae: A Multi-Messenger Perspective

The paper "Core-Collapse Supernovae, Neutrinos, and Gravitational Waves" authored by C. D. Ott et al. provides a comprehensive review of the current understanding and modeling of core-collapse supernovae (CCSNe). It highlights recent theoretical advancements and explores how these cosmic events serve as laboratories for fundamental physics.

Key Insights and Results

The paper emphasizes the multidimensional nature of the processes involved in CCSNe explosions, specifically focusing on neutrino-driven convection and the standing accretion shock instability (SASI). The authors argue that capturing these processes is crucial for a realistic model of the supernova explosion mechanism. They also speculate that neutrino emissions and gravitational waves from such events could provide invaluable insights into the structure and dynamics of the progenitor star, the angular momentum distribution, and the nuclear equation of state at high densities.

Notably, the research investigates the role of supernova neutrinos in probing the fundamental properties of neutrinos themselves. One bold prediction is how the rise time of the electron antineutrino flux observed on Earth could be utilized to infer the neutrino mass hierarchy, a pivotal question in particle physics. The authors provide numerical simulations demonstrating how these theoretical models could yield robust signals distinguishable by detectors like IceCube.

Additionally, the paper discusses potential signatures of gravitational waves from CCSNe. It suggests that next-generation gravitational wave detectors could capture emission patterns indicative of the asymmetric dynamics within the collapsing core. These signals, when analyzed alongside the neutrino data, promise to deepen our understanding of the supernova engine.

Theoretical and Practical Implications

The paper has profound implications both theoretically and practically. Theoretically, it advances our understanding of the complex physics governing supernovae explosions, extending to neutrino physics and general relativity. Practically, it paves the way for leveraging observations of neutrinos and gravitational waves as diagnostic tools for probing stellar phenomena.

In detail, discerning the neutrino mass hierarchy through supernova neutrino detection holds significant promise for neutrino astronomy and could resolve longstanding debates in neutrino physics. Concurrently, the achievement of detecting gravitational waves would not only affirm the presence of dynamic asphericities in CCSNe but also provide empirical data to refine existing theoretical models.

Speculation on Future Directions

While the paper provides a robust foundation, further advancements in modeling and simulation techniques, alongside technological improvements in observational instruments, are expected to substantially diminish the uncertainties that currently restrict a full understanding. Future endeavors will likely focus on developing fully three-dimensional models that integrate detailed radiation transport and magnetohydrodynamic effects. Moreover, collaborations between international observational programs could enhance the sensitivity and range of both neutrino and gravitational wave detections, possibly uncovering new phenomena not yet predicted by current models.

Conclusion

This paper by Ott et al. stands as a methodical exposition of the present knowledge in the field of core-collapse supernovae, elucidating both well-established theories and emerging questions. By combining theoretical models with observational prospects, it invites a future where multi-messenger astrophysics can provide a more comprehensive picture of these intriguing cosmic events. As such, this work contributes significantly to the broader scientific effort to unravel the mysteries behind some of the universe's most energetic occurrences.