Letters of Intent received in 2015

LoI 2017-282
SN 1987A 30 years after - Cosmic Rays and Nuclei from Supernovae and their aftermaths

Topics

- Review on Historical SNe
- SN 1987A at 30 years
- Stellar progenitors and diversity in SN explosions and compact object manifestations
- Explosion mechanisms and Nucleosynthesis
- Particle acceleration and Origin of cosmic-rays
- Multi-wavelength/multi-messenger data on SNe and their aftermaths
- Effects of SNe on large-scale structures in galaxies and star formation

Rationale

As the key sources of cosmic high-energy particles and heavy elements, the primary agents of chemical and dynamical evolution of galaxies, and the rare celestial events visible with the naked eye, Supernovae (SNe) and their aftermaths (Supernova Remnants [SNRs], Pulsars [PSRs] and their Wind Nebulae [PWNe], Superbubbles [SBs]) are central in many active fields of research: ancient and modern records of historical SNe and SN candidates, stellar evolution, explosion mechanisms and the associated nucleosynthesis, particle acceleration and the origin of cosmic rays, and feedback at large scales on the interstellar medium in galaxies. Yet, many open issues still need to be addressed. The nature of the core-collapse SN progenitors leading to the diversity in the SN explosions and their compact remnants is still intensively debated. Although type Ia SNe play a crucial role as standardizable cosmological candles, recent studies on the nature of their progenitors seem to point towards a larger diversity than previously thought. Now that state-of-the-art three-dimensional core-collapse and thermonuclear SN simulations have resulted in successful explosions, several aspects of the explosion scenarios need to be clarified and the subsequent explosive nucleosynthesis remains to be fully explored. While particle acceleration has long been known to occur in SNe and their aftermaths, the origin of cosmic rays (electrons, positrons, nuclei) is not yet settled, in spite of several decades of intensive observational and theoretical investigations.

SN 1987A, the only naked-eye SN event since the Kepler SN (AD 1604), was discovered on February 24, 1987 in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud. Thanks to its proximity, it is the first SN to be observed in its entire electromagnetic spectrum, from radio to gamma-rays, and this wealth of information has thus provided much insight into core-collapse SNe. Since then, the evolution of the remnant has been closely monitored, and both thermal and non-thermal processes occurring at shocks have been unveiled through these multi-wavelength observations. At the occasion of the 30th anniversary of this unique event, we propose a meeting whose main rationale is to make the link between the stellar SN progenitors and the multi-wavelength/multi-messenger manifestation of their aftermaths in terms of extreme sources of high-energy particles and nuclei. Thanks to the large panel of existing ground-based and space telescopes, from radio to very-high-energy gamma-rays, together with the new high-energy neutrino and gravitational wave experiments, in combination with the latest theoretical studies and state-of-the-art simulations of these extreme sources, we plan to address the following topics:

- Review on Historical SNe
- SN 1987A at 30 years
- Stellar progenitors and diversity in SN explosions and compact object manifestations
- Explosion mechanisms and Nucleosynthesis
- Particle acceleration and Origin of cosmic-rays
- Multi-wavelength/multi-messenger data on SNe and their aftermaths
- Effects of SNe on large-scale structures in galaxies and star formation

We believe that such a symposium is very timely given the rapid progress in this interdisciplinary research field made in the last decade, from extensive simulations of SNe and their aftermaths, their effects on star formation and on galaxy structure, nucleosynthesis and particle acceleration, to broadband observations with the current ground-based and space facilities. Moreover, prospectives with the upcoming large telescopes such as the Square Kilometer Array (SKA), the Large Synoptic Survey Telescope (LSST) and the Cherenkov Telescope Array (CTA) for 2020 and the interest of the high-energy neutrino (KM3NeT, IceCube-Gen2) and gravitational wave (Advanced LIGO/VIRGO) astronomies will be thoroughly addressed.

Dr M. Renaud (LUPM, CNRS-IN2P3, University of Montpellier, France), Prof G. Dubner (IAFE, University of Buenos Aires, Argentina), Prof Alak Ray (TIFR, Mumbai, India) and Prof A. Bykov (IOFFE, St-Petersburg, Russia) will act as co-chairs of the SOC. During the preparation of the final proposal, we will pay special attention to guarantee scientific, geographical and gender diversity balance both in the SOC and among the invited speakers and session chairs. We will also consider the particular importance for early career astronomers to have the opportunity to present their work at this large-scale symposium.

SN/SNR communities have held IAU Symposia at some occasions, the latest one (IAUS 296: Supernova environmental impacts, co-chair: A. Ray) having taken place in India in 2013 with good success (100 participants). Among all the conferences organized worldwide at the occasion of a decadal anniversary of SN 1987A, this would be the first symposium with IAU sponsorship. We also hope that the selection of this venue, in La Reunion island, will allow greater participation by countries in the Africa, Asia and Oceania regions.

Dr M. Renaud will also serve as chair of the LOC and will be supported by both the LUPM institute at the University of Montpellier and Les Makes Observatory in La Reunion island. The final venue in La Reunion will be selected shortly. We are aware that the intended dates of the symposium, during the week of the 30th anniversary of SN 1987A, in February 2017, could lead to a tight timeline. Therefore, we have already started investigating the possibility to postpone the meeting to a later date (May-June 2017). We believe it is important to use this rare opportunity to promote Astrophysics and Astronomy among the students, teachers and interested people in this region of the Indian Ocean through an active outreach program comprising school and public talks, exhibitions and observing sessions at Les Makes Observatory.

We intend to submit the scientific case for the symposium to IAU Divisions D (High Energy Phenomena and Fundamental Physics), G (Stars and Stellar Physics), C (Education, outreach and Heritage), B (Facilities, Technologies and Data Science).

Best Regards,

Matthieu Renaud