Synthesis of radioactive elements in novae and supernovae and their use as a diagnostic tool

TL;DR

This paper discusses how radioactive isotopes produced in novae and supernovae can be used as diagnostic tools through gamma-ray detection, highlighting current observational limitations and the need for more sensitive instruments.

Contribution

It emphasizes the importance of gamma-ray diagnostics in understanding explosion mechanisms and advocates for new, more sensitive detectors in space.

Findings

Radioactive isotopes provide insights into explosion mechanisms.

Gamma-ray lines have been detected in a few supernovae and remnants.

Current detector sensitivity limits the number of observable events.

Abstract

Novae and supernovae play a key role in many fields of Astrophysics and Cosmology. Despite their importance, an accurate description of which objects explode and why and how they explode is still lacking. One of the main characteristics of such explosions is that they are the main suppliers of newly synthesized chemical elements in the Galaxy. Since some of these isotopes are radioactive, it is possible to use the corresponding gamma-rays as a diagnostic tool of the explosion thanks to their independence on the thermal state of the debris. The drawback is the poor sensitivity of detectors in the MeV energy domain. As a consequence, the radioactive lines have only been detected in one core collapse supernova (SN 1987A), one Type Ia supernova (SN 2014J), and one supernova remnant (Cas A). Nevertheless these observations have provided and are providing important information about the explosion mechanisms. Unfortunately, novae are still eluding detection. These results emphasize the necessity to place as soon as possible a new instrument in orbit with enough sensitivity to noticeably enlarge the sample of detected events