13ª Semana Integrada do Instituto de Física de São Carlos

Simulating the gamma-ray emission signature of the central molecular zone

21 de ago. de 2023 16:00

1h 30m

Salão de Eventos USP

Normal 16h00 - 17h30

Descrição

The Galactic Center (GC) represents a remarkably intricate and diverse celestial region, hosting numerous sources of cosmic-ray acceleration and non-thermal high-energy emission. Notably, a recent breakthrough has been made with the identification of a cosmic Pevatron, associated with the central supermassive black hole known as Sagittarius A*. (1) Adjacent to the GC lies the Central Molecular Zone (CMZ), an expansive expanse spanning 600 parsecs within our Galaxy's inner regions, consisting of vast, high-density giant molecular clouds. The interaction between the high-energy cosmic rays accelerated by this Pevatron and the surrounding molecular clouds can yield substantial gamma-ray emissions through pion production and subsequent decay. To comprehensively interpret the observed gamma-ray emissions from the GC, it becomes imperative to grasp the various models pertaining to the CMZ's density distribution along the line of sight. Consequently, our study focuses on constructing radiative models capable of elucidating the gamma-ray emissions from the GC as detected by gamma-ray telescopes. By employing simulations, we evaluate the gamma-ray flux received on Earth using distinct models for cosmic-ray source and propagation, along with multiple models defining the 3D geometry of the CMZ. (2) Finally, we compare our findings with data obtained from the H.E.S.S telescope to ascertain the validity and effectiveness of our models.

Referências

1 ABRAMOWSKI, A. et al. Acceleration of petaelectronvolt protons in the Galactic Centre. Nature, v. 531, n. 7595, p. 476-479, 2016.

2 AHARONIAN, F. A.; ATOYAN, A. M. On the emissivity of π^0^-decay gamma radiation in the vicinity of accelerators of galactic cosmic rays. Astronomy and Astrophysics, v. 309, p. 917-928, 1996.