High-energy astrophysics of galaxies and AGN in the cosmological context by connecting numerical simulations and observations with the CTA and ASTRI Mini-Array

Abstract

Feedback from star-formation, supernovae explosions, and active galactic nuclei (AGN) accretion, are some of the most-energetic events in the Universe. These are observed to generate powerful galactic outflows, influence galaxy evolution on cosmological scales. This project aims to explore problems of high-energy astrophysical phenomena in galaxies and AGN, in the cosmological context over the past 12 Gyr, which form unsolved questions of Astronomy. There will be close collaboration with expert researchers at Instituto de Astronomia, Geofísica e Ciências Atmosféricas, of the Universidade de Sao Paulo (IAG-USP): the group of Prof. Elisabete de Gouveia Dal Pino and her collaborators. One main aim is to make predictions for the upcoming gamma-ray observing instruments: Cherenkov Telescope Array (CTA), and its precursor - the ASTRI MINI-ARRAY. The scientific objectives are to characterize energetic events of the following 4 broad categories, and how to observe them at earlier epochs using gamma-rays: (1) Feedback from star-formation and supernovae explosion in galaxies driving galactic winds, affecting the origin of diffuse intergalactic magnetic fields. (2) Gas accretion onto central supermassive black holes in AGN; modeling radio galaxy jet/lobe expansion and power evolution, to constrain the magnetic field strength and the jet propagation speed; outflows driven by AGN feedback and galaxy-AGN co-evolution; high-energy diffuse gamma-ray emission coming from AGN populations, to set predicted constraints on the extragalactic background light. (3) Dark matter self-annihilation signatures from gamma-ray detection. (4) Support the preparation of the CTA and ASTRI MINI-ARRAY to observe high-energy phenomena: perform Monte-Carlo simulations/analysis; evaluate the performance of the array configurations. The project will use an approach going beyond the state-of-the-art, by directly connecting next-generation theoretical models, numerical simulations, and observations. We propose to use at least two numerical codes: (i) 3D SPH GADGET-3, which combines hydrodynamics with cosmology, and contains novel baryonic feedback models (Barai et al. 2015) - metal cooling, star-formation, chemical enrichment, supernovae and AGN feedback. (ii) Godunov-based magneto-hydrodynamical (MHD) AMON, developed in the group of Prof. de Gouveia Dal Pino. Using IAG-USP local and external supercomputing resources, we will perform a series of new hydrodynamical, MHD, and Monte-Carlo simulations: cosmological volumes, single galaxies, isolated sources. The output would be analyzed to extract synthetic observables, compare the simulation results with observations of astronomical energetic events (especially in the gamma-rays), examine, and deduce physical interpretations. The proposed investigation of high-energy astrophysical phenomena taking into account the large-scale cosmological environments uniquely lies at the forefront of cutting-edge research in Astronomy. The project contributes to the competitiveness of Brazil in petascale computing research, by providing theoretical predictions for the upcoming CTA, which is one of the most ambitious scientific collaboration in the world. Many more energetic events would start to be detected in gamma-ray observations using the precursor ASTRI MINI-ARRAY and full CTA later, which has not been widely simulated; therefore it is important and timely to explore these. I shall perform dissemination and exploitation of the scientific output: publish scholarly articles (1 to 2 papers per year) in reputed Astrophysics journals, present results to the broader Astronomy community at international conferences/seminars, and to the broad public in local outreach activities at Sao Paulo. This grant will help me to reinforce my position of professional maturity, and set up long-term independent research directions. (AU)