Search for gamma-ray emission from a galactic supernova with the anticoincidence system of SPI

TL;DR

This study evaluates the potential of the SPI anticoincidence system on INTEGRAL to detect early gamma-ray emission from a galactic Type Ia supernova, providing insights into explosion mechanisms.

Contribution

It demonstrates the feasibility of detecting early gamma-ray signals from a galactic supernova using SPI's anticoincidence system, considering various models and distances.

Findings

Detection possible 6-12 days post-explosion

Can rule out hidden supernovae during INTEGRAL's lifetime

Detection depends on explosion model and pointing direction

Abstract

The detection of the very early gamma-emission of a Type Ia supernova (SNIa) could provide a deep insight on the explosion mechanism and nature of the progenitor. However this has not been yet possible as a consequence of the expected low luminosity and the distance at which all the events have occurred up to now. A SNIa occurring in our Galaxy could provide a unique opportunity to perform such measurement. The problem is that the optical flux would probably be so attenuated by interstellar extinction that would prevent triggering the observations with gamma-spectrometers at the due time. In this paper we analyse the possibility of using the anticoincidence system (ACS) of the spectrometer SPI on board of the INTEGRAL space observatory for detecting the early gamma-ray emission of a SNIa as a function of the explosion model and distance as well as of pointing direction. Our results suggest that such detection is possible at about 6 - 12 days after the explosion and, at the same time, we can discard missing any hidden explosion during the lifetime of INTEGRAL.