The influence of streaming velocities and Lyman–Werner radiation on the formation of the first stars
Year: 2021
Type: article
Abstract: ABSTRACT The first stars in the Universe, the so-called Population III stars, form in small dark matter minihaloes with virial temperatures Tvir < 104 K. Cooling in these minihaloes is dominated by molecular hydrogen (H2), and so Population III star formation is only possible in those minihaloes that form enough H2 to cool on a short timescale. As H2 cooling is more effective in more massive minihaloes, there is therefore a critical halo mass scale Mmin above which Population III star formation first becomes possible. Two important processes can alter this minimum mass scale: streaming of baryons relative to the dark matter and the photodissociation of H2 by a high redshift Lyman–Werner (LW) background. In this paper, we present results from a set of high resolution cosmological simulations that examine the impact of these processes on Mmin and on Mave (the average minihalo mass for star formation), both individually and in combination. We show that streaming has a bigger impact on Mmin than the LW background, but also that both effects are additive. We also provide a fitting functions quantifying the dependence of Mave and Mmin on the streaming velocity and the strength of the LW background.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,247
Funders: National Aeronautics and Space Administration, California Department of Fish and Game, Space Telescope Science Institute, European Commission, Deutsche Forschungsgemeinschaft, Gujarat Cancer Society, Gauss Centre for Supercomputing, Science and Technology Facilities Council, Leibniz-Rechenzentrum, H2020 European Research Council
Awards: G1620761618, G1627648589, G1701466713, G1834425647, G2340603345, G2394671121, A Gaia and Herschel Study of the Density Distribution and Evolution of Young Massive Star Clusters, G3362242745, Understanding our Galactic ecosystem: From the disk of the Milky Way to the formation sites of stars and planets, G4154112718, G433322167, G4421380937, G5284521312, G5313774521, G5583297626, G58316358, G6075447204, G6273510985, G6526081583, G6665833600, EXC 2181: STRUKTUREN: Emergenz in Natur, Mathematik und komplexen Daten, G7227535049, SFB 881: Das Milchstraßensystem, G8043653733, G8832408132, G884397560
OpenAlex ID: W3048893864