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Related papers: The First Stars: formation under cosmic ray feedba…

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[abridged]We use 3D cosmological simulations with radiative transfer to study the formation and evolution of the first galaxies in a LCDM cosmology. We find that the first luminous objects ("small-halos") are characterized by a bursting…

Astrophysics · Physics 2009-11-07 Massimo Ricotti , Nickolay Y. Gnedin , J. Michael Shull

Population III stars are believed to have been more massive than typical stars today and to have formed in relative isolation. The thermodynamic impact of metals is expected to induce a transition leading to clustered, low-mass Population…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Chalence Safranek-Shrader , Milos Milosavljevic , Volker Bromm

Many recent numerical studies have argued that cosmic rays (CRs) from supernovae (SNe) or active galactic nuclei (AGN) could play a crucial role in galaxy formation, in particular by establishing a CR-pressure dominated circum-galactic…

Astrophysics of Galaxies · Physics 2023-08-29 Philip F. Hopkins , Iryna S. Butsky , Suoqing Ji , Dusan Keres

The first massive stars may influence the formation of second-generation stars, in part by their metal enrichment of the surrounding gas. We investigate the "critical metallicity", defined as the the value, Z_crit, at which primordial gas…

Astrophysics · Physics 2008-11-26 J. Michael Shull

It has been hypothesized that the cosmic microwave background (CMB) provides a temperature floor for collapsing protostars that can regulate the process of star formation and result in a top-heavy initial mass function at high metallicity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jeremy Bailin , Greg Stinson , Hugh Couchman , William E. Harris , James Wadsley , Sijing Shen

Cosmic ray (CR) feedback in galaxy evolution has seen a theoretical resurgence in the past decade, but significant uncertainties remain in CR transport through the interstellar and circum-galactic media (ISM and CGM). While several works…

Astrophysics of Galaxies · Physics 2025-09-04 Sam B. Ponnada

We study the impact of cosmic rays (CRs) on the structure of virial shocks, using a large suite of high-resolution cosmological FIRE-2 simulations accounting for CR injection by supernovae. In massive ($M_{\rm halo} \gtrsim…

The evolution of a gas shell, swept by the supernova remnant of a massive first generation star, is studied with H_2 and HD chemistry taken into account. When a first-generation star explodes as a supernova, H_2 and HD molecules are formed…

In order to constrain the initial mass function (IMF) of the first generation of stars (Population III), we investigate the fragmentation properties of metal-free gas in the context of a hierarchical model of structure formation. We…

Astrophysics · Physics 2009-10-31 Volker Bromm , Paolo S. Coppi , Richard B. Larson

The formation of the Universe's first luminous stellar structures depends on the unique conditions at "Cosmic Dawn," which are set by the underlying cosmological model and early baryonic physics. Observations suggest that high-$z$ star…

We present hydrodynamic and magnetohydrodynamic (MHD) simulations of sub galactic regions including photoionising and supernova feedack. We aim to improve the initial conditions of our region extraction models by including an initial…

Astrophysics of Galaxies · Physics 2023-04-14 Nicholas P. Herrington , Clare L. Dobbs , Thomas J. R. Bending

We report results from numerical simulations of star formation in the early universe that focus on gas at very high densities and very low metallicities. We argue that the gas in the central regions of protogalactic halos will fragment as…

Astrophysics · Physics 2009-06-23 Paul C. Clark , Simon C. O. Glover , Ralf S. Klessen

We study star cluster formation at low metallicities of $Z/Z_\odot=10^{-4}$--$10^{-1}$ using three-dimensional hydrodynamics simulations. Particular emphasis is put on how the stellar mass distribution is affected by the cosmic microwave…

Astrophysics of Galaxies · Physics 2022-06-22 Sunmyon Chon , Haruka Ono , Kazuyuki Omukai , Raffaella Schneider

Cosmic rays (CRs) are a non-thermal energy component in the interstellar and circumgalactic medium (CGM) that can act as an additional feedback channel beyond thermal and kinetic feedback from stars and AGN. They influence galaxy evolution…

We investigate the impact of cosmic rays (CRs) on galactic outflows from a multi-phase interstellar medium with solar neighbourhood conditions. The three-dimensional magneto-hydrodynamical simulations include CRs as a relativistic fluid in…

Astrophysics of Galaxies · Physics 2018-07-11 Philipp Girichidis , Thorsten Naab , Michał Hanasz , Stefanie Walch

We simulate the formation of a metal-poor (10^-2 Zsun) stellar cluster in one of the first galaxies to form in the early Universe, specifically a high-redshift atomic cooling halo (z~14). This is the first calculation that resolves the…

Astrophysics of Galaxies · Physics 2014-06-19 Chalence Safranek-Shrader , Milos Milosavljevic , Volker Bromm

Understanding star formation is problematic as it originates in the large scale dynamics of a galaxy but occurs on the small scale of an individual star forming event. This paper presents the first numerical simulations to resolve the star…

Astrophysics of Galaxies · Physics 2015-06-12 Ian A. Bonnell , Clare L. Dobbs , Rowan J. Smith

Context: Molecular data of extreme environments, such as Arp 220, but also NGC 253, show evidence for extremely high cosmic ray (CR) rates (10^3-10^4 * Milky Way) and mechanical heating from supernova driven turbulence. Aims: The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 R. Meijerink , M. Spaans , A. F. Loenen , P. P. van der Werf

The first stars in the Universe are predicted to have been much more massive than the Sun. Gravitational condensation accompanied by cooling of the primordial gas due to molecular hydrogen, yields a minimum fragmentation scale of a few…

Astrophysics · Physics 2009-07-09 Volker Bromm , Abraham Loeb

Galactic cosmic rays (CR) are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the…

High Energy Astrophysical Phenomena · Physics 2016-05-25 M. Padovani , A. Marcowith , P. Hennebelle , K. Ferrière
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