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Related papers: Radiation Hydrodynamical Instabilities in Cosmolog…

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We study the ionization structure of galactic outflows in 37 nearby, star forming galaxies with the Cosmic Origins Spectrograph on the Hubble Space Telescope. We use the O I, Si II, Si III, and Si IV ultraviolet absorption lines to…

Astrophysics of Galaxies · Physics 2016-03-09 John Chisholm , Christy A. Tremonti , Claus Leitherer , Yanmei Chen , Aida Wofford

The time evolution of thermal and thermo-reactive instabilities of primordial gas in the presence of ionizing UV radiation is studied. We obtain conditions (depending on density, temperature, and UV radiation intensity) favorable for the…

Astrophysics · Physics 2007-05-23 Jan P. Muecket , Ronald E. Kates

We investigate hydromagnetic turbulence of primordial magnetic fields using magnetohydrodynamics (MHD) in an expanding universe. We present the basic, covariant MHD equations, find solutions for MHD waves in the early universe, and…

Astrophysics · Physics 2014-10-13 Axel Brandenburg , Kari Enqvist , Poul Olesen

Radiation flow through an inhomogeneous medium is critical in a wide range of physics and astronomy applications from transport across cloud layers on the earth to the propagation of supernova blast-waves producing UV and X-ray emission in…

The first stars are believed to have formed a few hundred million years after the big bang in so-called dark matter minihalos with masses ~10^6 M_sun. Their radiation lit up the Universe for the first time, and the supernova explosions that…

Astrophysics of Galaxies · Physics 2015-01-23 Thomas H. Greif

I use cosmological simulations that incorporate a physically motivated approximation to three-dimensional radiative transfer that recovers correct asymptotic ionization front propagation speeds for some cosmologically relevant density…

Astrophysics · Physics 2009-10-31 Nickolay Y. Gnedin

The dynamical impact of Lyman-alpha (Ly{\alpha}) radiation pressure on galaxy formation depends on the rate and duration of momentum transfer between Ly{\alpha} photons and neutral hydrogen gas. Although photon trapping has the potential to…

Astrophysics of Galaxies · Physics 2016-12-07 Aaron Smith , Volker Bromm , Abraham Loeb

The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other primordial gas-clouds and photoevaporating them. Results are presented…

Astrophysics · Physics 2007-05-23 Paul R. Shapiro , Alejandro C. Raga , Garrelt Mellema

Observations of the redshifted 21 cm line with upcoming radio telescopes promise to transform our understanding of the cosmic reionization. To unravel the underlying physical process, we investigate the 21 cm structures of three different…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Hidenobu Yajima , Yuexing Li

Here we examine the evolution of irradiated clouds using the Smoothed Particle Hydrodynamics ({\small SPH}) algorithm coupled with a ray-tracing scheme that calculates the position of the ionisation-front at each timestep. We present…

Astrophysics of Galaxies · Physics 2015-06-11 S. Anathpindika , H. C. Bhatt

A key result of hydrogravitational dynamics cosmology relevant to astrobiology is the early formation of vast numbers of hot primordial-gas planets in million-solar-mass clumps as the dark matter of galaxies and the hosts of first life.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Carl H. Gibson , N. Chandra Wickramasinghe , Rudolph E. Schild

The density distribution of the inter-galactic medium is an uncertain but highly important issue in the study of cosmic reionization. It is expected that there are abundant gas clouds hosted by low-mass "minihalos" in the early universe,…

Astrophysics of Galaxies · Physics 2021-01-06 Riouhei Nakatani , Anastasia Fialkov , Naoki Yoshida

The formation and mass distribution of the first stars depend on various environmental factors in the early universe. We compare 120 cosmological hydrodynamical simulations to explore how the baryonic streaming velocity (SV) relative to…

Astrophysics of Galaxies · Physics 2025-05-12 Shingo Hirano

Recent observations show that the measured rates of star formation in the early universe are insufficient to produce re-ionization, and therefore, another source of ionizing photons is required. In this \emph{Letter}, we examine the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Michael A. Dopita , Lawrence M. Krauss , Ralph S. Sutherland , Chiaki Kobayashi , Charles H. Lineweaver

The ultraviolet background (UVB) emitted by quasars and galaxies governs the ionization and thermal state of the intergalactic medium (IGM), regulates the formation of high-redshift galaxies, and is thus a key quantity for modeling cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-20 Jose Oñorbe , Joseph F Hennawi , Zarija Lukić

High resolution 2D hydrodynamical simulations describing the evolution of the hot ISM in axisymmetric two-component models of early-type galaxies well reproduced the observed trends of the X-ray luminosity ($L_\mathrm{x}$) and temperature…

Astrophysics of Galaxies · Physics 2015-05-01 Andrea Negri , Silvia Pellegrini , Luca Ciotti

From hydro-gravitational cosmology, hydrogen-helium gas planets fragmented at the plasma to gas transition 300,000 years after the big bang in million-star-mass clumps. Stars may form in the clumps by mergers of the planets to make globular…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-30 Carl H. Gibson , Rudolph E. Schild

In the first paper we presented 27 hydrodynamical cosmological simulations of galaxies with total masses between $5 \times 10^8$ and $10^{10}\,\mathrm{M}_\odot$. In this second paper we use a subset of these cosmological simulations as…

Astrophysics of Galaxies · Physics 2017-11-08 Jonas Frings , Andrea V. Macciò , Tobias Buck , Camilla Penzo , Aaron A. Dutton , Aura Obreja , Marvin Blank

The physical basis for the belief that the abundant old dwarf galaxies seen in present-day galaxy clusters formed before reionization of the universe is very compelling, because (1) the observed faint end slope of the galaxy luminosity…

Astrophysics · Physics 2007-05-23 Renyue Cen

We present general properties of ionized hydrogen (HII) bubbles and their growth based on a state-of-the-art large-scale (100 Mpc/h) cosmological radiative transfer simulation. The simulation resolves all halos with atomic cooling at the…

Astrophysics · Physics 2009-11-13 Min-Su Shin , Hy Trac , Renyue Cen