相关论文: Photoionization Effects During Galaxy Formation
Recent years have seen a surge of interest in the community studying the effect of ultraviolet radiation environment, predominantly set by OB stars, on protoplanetary disc evolution and planet formation. This is important because a…
We present a brief overview of some recent observations of colliding galaxies and relevant numerical simulations. These are compared, and details of the locations and history of collision induced star formation are explored, with possible…
Ionization fronts, the sharp radiation fronts behind which H/He ionizing photons from massive stars and galaxies propagate through space, were ubiquitous in the universe from its earliest times. The cosmic dark ages ended with the formation…
The photometric evolution of galaxies in a hierarchically clustering universe is investigated. The study is based on high resolution numerical simulations which include the effects of gas dynamics, shock heating, radiative cooling and a…
We propose that UV radiation can stimulate the formation of planetesimals in externally-illuminated protoplanetary disks. We present a numerical model of disk evolution including vertical sedimentation and photo-evaporation by an external O…
Magnetic fields play a vital role in numerous astrophysical processes such as star formation and the interstellar medium. In particular, their role in the formation and evolution of galaxies is not well understood. This paper presents…
This contribution contains the introductory remarks that I presented at IAU Symposium 270 on ``Computational Star Formation" held in Barcelona, Spain, May 31 -- June 4, 2010. I discuss the historical development of numerical MHD methods in…
UV radiation can induce photochemical processes in exoplanet atmospheres and produce haze particles. Recent observations suggest that haze and/or cloud layers could be present in the upper atmospheres of exoplanets. Haze particles play an…
The chemical and photometric evolution of star forming disk galaxies is investigated. Numerical simulations of the complex gasdynamical flows are based on our own coding of the Chemo - Dynamical Smoothed Particle Hydrodynamical (CD - SPH)…
In this paper we consider the effect of the direct ionizing stellar radiation field on the evolution of protoplanetary discs subject to photoevaporative winds. We suggest that models which combine viscous evolution with photoevaporation of…
In this talk I will present a model for primordial galaxy formation. In particular, I will review the feedback effects that regulate the process: (i) radiative (i.e. ionizing and H_2-photodissociating photons) and (ii) stellar (i.e. SN…
In this paper, we examine numerically the difference between triggered and revealed star formation. We present Smoothed Particle Hydrodynamics (SPH) simulations of the impact on a turbulent 10^4 solar-mass molecular cloud of irradiation by…
We perform radiation hydrodynamics simulations on the evolution of galactic gas disks irradiated by ultraviolet radiation background. We find gas disks with N_H > 10^21 cm^-2 exposed to ultraviolet radiation at a level of I_21=1 can be…
We present a new, on-the-fly photon flux and absorption tracer algorithm designed to directly measure the contribution of different source populations to the metagalactic UV background and to the ionisation fraction of gas in the Universe.…
The temporal evolution of the ionizing UV background radiation field at high redshift provides a probe of the evolution of the early star formation rate. By comparing the observed levels of absorption in the highest redshift quasar spectra…
The first generations of astrophysical objects made a substantial impact on our Universe with their radiation. X-rays from the first sources, with large mean free paths, likely quickly heated the intergalactic medium (IGM). The second…
We present the predictions for the photometric and emission line properties of galaxies present during the latter stages of reionization from z=8 to 6. These preliminary predictions are made from cosmological hydrodynamic simulations that…
Massive stars disproportionately influence their surroundings. How they form has only started to become clear recently through radiation gas dynamical simulations. However, until now, no simulation has simultaneously included both magnetic…
The results from hydrodynamical TREESPH simulations of galaxy clusters are used to investigate the dependence of the final cluster X-ray properties upon the numerical resolution and the assumed star formation models for the cooled gas. When…
The rest-frame UV emission from massive stars contains a wealth of information about the physical nature and conditions of star formation in galaxies. Using studies of the rest-frame UV, the past decade has witnessed the beginning of…