ASTENA: a mission concept for a deep study of the transient gamma-ray sky and for nuclear astrophysics by E. Virgilli et al. on Wednesday 30 November

Gamma-ray astronomy is a branch whose potential has not yet been fully

exploited. The observations of elemental and isotopic abundances in supernova

(SN) explosions are key probes not only of the stellar structure and evolution

but also for understanding the physics that makes Type-Ia SNe as standard

candles for the study of the Universe expansion properties. In spite of its

crucial role, nuclear astrophysics remains a poorly explored field mainly for

the typical emission lines intensity which are vanishing small and requires

very high sensitivities of the telescopes. Furthermore, in spite that the

Galactic bulge-dominated intensity of positron annihilation line at 511 keV has

been measured, its origin is still a mystery due to the poor angular resolution

and insufficient sensitivity of the commonly employed instrumentation in the

sub-MeV energy domain. To answer these scientific issues a jump in sensitivity

and angular resolution with respect to the present instrumentation is required.

Conceived within the EU project AHEAD, a new high energy mission, capable of

tackling the previously mentioned topics, has been proposed. This concept of

mission named ASTENA (Advanced Surveyor of Transient Events and Nuclear

Astrophysics), includes two instruments: a Wide Field Monitor with Imaging and

Spectroscopic (WFM-IS, 2 keV - 20 MeV) capabilities and a Narrow Field

Telescope (NFT, 50 - 700 keV). Thanks to the combination of angular resolution,

sensitivity and large FoV, ASTENA will be a breakthrough in the hard X and soft

gamma--ray energy band, also enabling polarimetry in this energy band. In this

talk the science goals of the mission are discussed, the payload configuration

is described and expected performances in observing key targets are shown.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16916v1