We perform hydrodynamical simulations of a young galactic disc embedded in a hot gaseous halo using parameters typical for Lyman break galaxies (LBGs). We take into account the (static) gravitational potentials due to a dark matter halo, a stellar bulge and a disc of stars and gas. Star formation is treated by a local Kennicutt-Schmidt law. We simplify the structure of the interstellar medium by restricting the computational domain to a 25th of the full azimuthal angle, effectively assuming large-scale axisymmetry and neglecting any effects of spiral structure, and focus on the large-scale ISM drivers, the superbubbles. Supernovae are triggered randomly and have preset event sizes of several tens to hundreds. We further investigate different halo gas pressures and energy injection methods. Many of our simulated galaxies, but not all, develop bipolar outflows. We characterise the strength of the outflow by mass and energy outflow rates, and investigate the effect of changes to the details of the model. We find that supernovae are more effective if comprised into larger superbubbles. The weight and the pressure of the halo gas is able to quench galactic outflows. The wind emerges from a series of superbubbles in regions where a critical star formation density is exceeded. The superbubbles expand into the gaseous halo at slightly supersonic speed, producing radiative shock waves with similar characteristics as the absorptions systems observed around LBGs.
Tracing ionized gas kinematics in Lyman-Break Analogs. Implications for star formation compactness and outflow properties
Universidad de La Serena（拉塞雷纳大学）；Instituto de Astrofísica de Andalucía (CSIC)（安达卢西亚天体物理研究所）；Centro de Estudios de Física del Cosmos de Aragón (CEFCA)（阿拉贡宇宙物理学研究中心）；INAF - Osservatorio Astronomico di Roma（意大利国家天文台罗马天文台）；Michigan Institute for Data Science, University of Michigan（密歇根大学数据科学研究所）
This paper is the second in a series aimed at examining the gaseous environments of z$\le$0.3 quasars and ultraluminous infrared galaxies (ULIRGs) as a function of AGN/host galaxy properties across the merger sequence. This second paper focuses on the Ly$α$ emission and O VI and N V absorption features, tracers of highly ionized gas outflows, in ULIRGs observed with HST/COS. Ly$α$ emission is detected in 15 out of 19 ULIRGs, and 12 of the 14 clear Ly$α$ detections show emission with blueshifted velocity centroids and/or wings. The equivalent widths of the Ly$α$ emission increase with increasin…
We use cosmological hydrodynamic simulations with stellar feedback from the FIRE project to study the physical nature of Lyman limit systems (LLSs) at z<1. At these low redshifts, LLSs are closely associated with dense gas structures surrounding galaxies, such as galactic winds, dwarf satellites, and cool inflows from the intergalactic medium. Our analysis is based on 14 zoom-in simulations covering the halo mass range M_h~10^9-10^13 Msun at z=0, which we convolve with the dark matter halo mass function to produce cosmological statistics. We find that the majority of cosmologically-selected LL…
