THE GENERATION OF STRONG MAGNETIC FIELDS DURING THE FORMATION OF THE FIRST STARS

By S. Sur, D. Schleicher, Robi Banerjee, Christoph Federrath, Ralf Klessen. 2010

133 citations recorded by the source corpus.

Cosmological hydrodynamical simulations of primordial star formation suggest that the gas within the first star-forming halos is turbulent. This has strong implications on the subsequent evolution, in particular on the generation of magnetic fields. Using high-resolution numerical simulations, we show that in the presence of turbulence, weak seed magnetic fields are exponentially amplified by the small-scale dynamo during the formation of the first stars. We conclude that strong magnetic fields are generated during the birth of the first stars in the universe, potentially modifying the mass distribution of these stars and influencing the subsequent cosmic evolution. We find that the presence of the small-scale turbulent dynamo can only be identified in numerical simulations in which the turbulent motions in the central core are resolved with at least 32 grid cells.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/b8ae7041bf7cf21fdf8ab667bf6d59d3b9646c76

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Citations in the corpus

Cosmological Magnetic Fields: Their Generation, Evolution and Observation (2013, methodology): “Further processing of the fields by the MHD processes occurs during structure formation (Ryu et al 2008; Schleicher et al 2010; Sur et al 2010).”
Inefficient star formation through turbulence, magnetic fields and feedback (2015, background): “…costly, but guarantees that we resolve turbulence on the Jeans scale (Federrath et al. 2011), potential dynamo amplification of the magnetic field in the dense cores (Sur et al. 2010), and capture the basic structure of accretion discs forming on the smallest scales (Federrath et al. 2014).”
The First Stars (2012, methodology): “Sur et al. (2010) therefore focussed on the effects of resolution, performing five different simulations with the same initial conditions, but with different grid refinement criteria. Starting with a model in which the refinement criterion ensures that the Jeans length is always resolved by 8 grid z”
On the universality of supersonic turbulence (2013, background): “…α < 1 (e.g. α = 1/3 for Kolmogorov and α = 1/2 for Burgers turbulence as reasonable limiting cases), increasing the resolution leads to higher levels of vorticity, as the effective viscosity of the gas decreases and the effective Reynolds number increases (Sur et al. 2010; Federrath et al. 2011b).”
Primordial star formation under the influence of far ultraviolet radiation: 1540 cosmological haloes and the stellar mass distribution (2015, background): “Moreover, recent magnetohydrodynamic simulations show that even a small amount of turbulence can amplify magnetic fields by a dynamo mechanism (Sur et al. 2010; Federrath et al. 2011; Sur et al. 2012; Turk et al. 2012).”
Possible indirect confirmation of the existence of Pop III massive stars by gravitational wave (2014, background): “According to their results, the turbulent motions driven in the galaxy formation might increase the magnetic field up to <10−6 G (Schleicher et al. 2010; Sur et al. 2010; Schober et al. 2012; Turk et al. 2012), which is similar value to that in molecular clouds of the galaxy.”
Titans of the early Universe: The Prato statement on the origin of the first supermassive black holes (2018, methodology): “The amplification timescale is comparable to the eddy-turnover time on viscous or resistive length scales (Kazantsev 1968; Subramanian 1998; Sur et al. 2010, 2012; Schober et al. 2012a, 2012b) depending on the Prandtl numbers, and in either case is much shorter than the dynamical or collapse…”
On the universality of interstellar filaments: theory meets simulations and observations (2015, background): “…costly, but guarantees that we resolve turbulence on the Jeans scale (Federrath et al. 2011), potential dynamo amplification of the magnetic field in the dense cores (Sur et al. 2010), and capture the basic structure of accretion discs forming on the smallest scales (Federrath et al. 2014).”
Formation and evolution of primordial protostellar systems (2012, background): “Another complication is given by magnetic fields, which are thought to be important in minihaloes (e.g. Machida, Matsumoto & Inutsuka 2008; Xu et al. 2008; Schleicher et al. 2009, 2010; Sur et al. 2010; Federrath et al. 2011; Schober et al. 2012; Turk et al. 2012).”
ON THE STAR FORMATION EFFICIENCY OF TURBULENT MAGNETIZED CLOUDS (2012, background): “…than about 30 grid cells, i.e., k > kdiff with kdiff ∼ 512/30 ∼ 17 for the 5123- resolution spectra analyzed here, are typically affected by numerical diffusion (Kitsionas et al. 2009; Federrath et al. 2010b; Price & Federrath 2010; Sur et al. 2010; Federrath et al. 2011c; Kritsuk et al. 2011b).”
VERTICAL STRUCTURE OF A SUPERNOVA-DRIVEN TURBULENT, MAGNETIZED INTERSTELLAR MEDIUM (2012, methodology): “To test similar growth, we have run an additional model at 4 pc resolution, bx10, noting that Sur et al. (2010) and Federrath et al. (2011) have demonstrated effective dynamos with the HLL3R Riemann solver used in FLASH in this work.”
THE MASS SPECTRUM OF THE FIRST STARS (2014, methodology): “However, so far the sufficient amplification to affect the dynamics of the gas has not been shown starting from a very week seed field of ∼10−18–10−20 G by ab initio numerical simulations (Sur et al. 2010; Federrath et al. 2011; Turk et al. 2012; Latif et al. 2013).”
THE STAR FORMATION RATE OF TURBULENT MAGNETIZED CLOUDS: COMPARING THEORY, SIMULATIONS, AND OBSERVATIONS (2012, background): “In the more realistic case of turbulent flows, field lines become tangled, and the B–ρ correlation is a combination of compression of field lines and turbulent dynamo amplification (Schleicher et al. 2010; Sur et al. 2010; Federrath et al. 2011c; Turk et al. 2012; Schober et al. 2012).”
A NEW JEANS RESOLUTION CRITERION FOR (M)HD SIMULATIONS OF SELF-GRAVITATING GAS: APPLICATION TO MAGNETIC FIELD AMPLIFICATION BY GRAVITY-DRIVEN TURBULENCE (2011, methodology): “Initial conditions and setup of our MHD simulations of a collapsing dense core We present results of a numerical experiment with a collapsing, magnetized, turbulent gas core (see, Sur et al. 2010, paper I).”
Small-scale dynamo action during the formation of the first stars and galaxies - I. The ideal MHD limit (2010, background): “In a companion paper (Sur et al. 2010), we present numerical simulations confirming the importance of dynamo amplification during gravitational collapse.”
The density variance–Mach number relation in supersonic turbulence – I. Isothermal, magnetized gas (2012, background): “Aside from these reports, if the magnetic flux is not conserved, but increases due to turbulent dynamo amplification during compression, α can become larger than the values quoted above, depending on the Reynolds numbers of the gas (Schleicher et al. 2010; Sur et al. 2010; Federrath et al. 2011).”