Three-dimensional hydrodynamical simulations of the supernovae-driven gas loss in the dwarf spheroidal galaxy Ursa Minor

• Grant number: 15/06361-0
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Duration: May 01, 2015 - October 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Anderson Caproni
• Grantee: Anderson Caproni
• Host Institution: Centro de Ciências Exatas e Tecnológicas. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil

Abstract

As usual in dwarf spheroidal galaxies, the Local Group galaxy Ursa Minor is depleted of its gas content nowadays. How this galaxy lost its gas is still a matter of debate. To study the history of gas loss in Ursa Minor, we conducted for the first time three-dimensional (3D) hydrodynamical (HD) simulations for this object, assuming that the gas-loss was driven by galactic winds powered by type II supernovae (SNe) only. The initial gas setup and the SN rates used in our simulations are mainly constrained by the inferred star formation history and observed velocity dispersion of Ursa Minor. After 3 Gyr of evolution, we found that the efficiency in removing gas is higher when the SN rate is increased, as well as when the initial mean gas density is lowered. The derived mass-loss rates are systematically higher in the central regions (<300 pc), even though such relationship has not been strictly linear in time and in terms of the galactic radius. Filamentary structures induced by the Rayleigh--Taylor instabilities (RTI) and concentric shells related to acoustic waves driven by SNe can afford the inferred mass losses from the simulations. Our results suggest that type II SNe are able to transfer most of the gas from the central region outwards to the galactic halo. However other physical mechanisms must be considered in order to completely remove the gas at larger radii. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CAPRONI, A.; LANFRANCHI, G. A.; LUIZ DA SILVA, A.; FALCETA-GONCALVES, D.. THREE-DIMENSIONAL HYDRODYNAMICAL SIMULATIONS OF THE SUPERNOVAE-DRIVEN GAS LOSS IN THE DWARF SPHEROIDAL GALAXY URSA MINOR. ASTROPHYSICAL JOURNAL, v. 805, n. 2, JUN 1 2015. (15/06361-0, 09/54006-4, 11/12909-8)