Study of Al-26 in the COSI 2016 Superpressure Balloon Flight

Discussion timeslot (ZOOM-Meeting): 16. July 2021 - 18:00
ZOOM-Meeting URL: https://icrc2021.desy.de/pf_access_abstracts
Corresponding Session: https://icrc2021-venue.desy.de/channel/Presenter-Forum-1-Evening-All-Categories/48
Abstract:
"The Compton Spectrometer and Imager (COSI) is a balloon-borne compact Compton telescope (CCT) designed to survey the gamma-ray sky in 0.2-5 MeV. COSI's wide field of view, excellent energy resolution from cross-strip high-purity germanium semiconductor detectors, and improved angular resolution make it uniquely capable to probe this under-explored energy regime and make contributions to understanding of stellar nucleosynthesis, particularly through studies of diffuse emission from radioisotope Al-26 at 1.809 MeV. In 2016, COSI was launched from Wanaka, New Zealand on a NASA Superpressure balloon and flew for 46-days. The flight was a technologic and scientific success, boasting live detection and polarization studies of GRB160530A, imaging of the Crab Nebula and the 511-keV positron annihilation emission at the Galactic Center, and detection of Cyg-X1. This presentation details a new maximum-likelihood search for the 1.809 MeV signature of Galactic Al-26 in the 2016 data. The analysis reveals promising signs of an Al-26 signature, and further exploration is currently underway to solidify a measurement. Hence, this work demonstrates COSI's ability to reveal critical astrophysical nuclear lines and the powerful capabilities of CCTs like COSI on a balloon platform."

Authors: Jacqueline Beechert
Co-Authors: For the COSI collaboration
Collaboration: Compton Spectrometer and Imager (COSI)

Indico-ID: 374
Proceeding URL: https://pos.sissa.it/395/611