THE STAR FORMATION RATE OF SUPERSONIC MAGNETOHYDRODYNAMIC TURBULENCE

By P. Padoan, Åke Nordlund. 2009

340 citations recorded by the source corpus.

This work presents a new physical model of the star formation rate (SFR), which is verified with an unprecedented set of large numerical simulations of driven, supersonic, self-gravitating, magneto-hydrodynamic (MHD) turbulence, where collapsing cores are captured with accreting sink particles. The model depends on the relative importance of gravitational, turbulent, magnetic, and thermal energies, expressed through the virial parameter, αvir, the rms sonic Mach number, , and the ratio of mean gas pressure to mean magnetic pressure, β0. The SFR is predicted to decrease with increasing αvir (stronger turbulence relative to gravity), to increase with increasing (for constant values of αvir), and to depend weakly on β0 for values typical of star forming regions (–20 and β0 ≈ 1–20). In the unrealistic limit of β0 → ∞, that is, in the complete absence of a magnetic field, the SFR increases approximately by a factor of three, which shows the importance of magnetic fields in the star formation process, even when they are relatively weak (super-Alfvénic turbulence). The star-formation simulations used to test the model result in an approximately constant SFR, after an initial transient phase. The dependence of the SFR on the virial parameter is shown to agree very well with the theoretical predictions.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/a1b8935d0bbddf596ffdee497f60e19d94df17ab

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

In Statistical and Nonlinear Physics

Citations in the corpus

ANALYTICAL STAR FORMATION RATE FROM GRAVOTURBULENT FRAGMENTATION (2011, background): “Within the past few years, two analytical approaches have emerged, aiming at characterizing the SFR issued from the probability density function (PDF) of density fluctuations induced by turbulence in the cloud (Krumholz & McKee 2005-KM, Padoan & Nordlund 2011-PN).”
The structure of the interstellar medium of star‐forming galaxies (2011, background): “More recent – and much higher resolution – numerical work has highlighted, however, that star formation in such models proceeds more rapidly than previously appreciated (∼30 per cent per dynamical time) if turbulence is driven solely on large scales (Padoan & Nordlund 2011).”
Feedback-regulated star formation in molecular clouds and galactic discs (2013, methodology): “…turbulence being maintained within GMCs, an assumption that Krumholz & McKee (2005) used to predict a nearly universal volumetric star formation law of ∼ 0.01 of the gas mass turned into stars per free fall time in molecular gas (see also Padoan & Nordlund 2011; Federrath & Klessen 2012).”
ON THE STAR FORMATION EFFICIENCY OF TURBULENT MAGNETIZED CLOUDS (2012, background): “…2009; Elmegreen 2011; Veltchev et al. 2011; Donkov et al. 2012; Parravano et al. 2012; Hopkins 2012c,a), the Kennicutt-Schmidt relation (Krumholz & McKee 2005; Tassis 2007), the SFE (Elmegreen 2008), and the SFR (Krumholz & McKee 2005; Padoan & Nordlund 2011; Hennebelle & Chabrier 2011, Paper I).”
On the universality of supersonic turbulence (2013, background): “…2007), because it controls the rate of star formation triggered by gas compression in shocks (Krumholz & McKee 2005; Hennebelle & Chabrier 2011; Padoan & Nordlund 2011; Federrath & Klessen 2012), affects the star formation efficiency (Elmegreen 2008; Federrath & Klessen 2013; Kainulainen,…”
MODELING COLLAPSE AND ACCRETION IN TURBULENT GAS CLOUDS: IMPLEMENTATION AND COMPARISON OF SINK PARTICLES IN AMR AND SPH (2010, methodology): “…isothermal regime, as for instance in the large-scale simulations of colliding flows by Banerjee et al. (2009) and in the turbulent box calculations by Padoan & Nordlund (2009), where sink particles are formed at much lower densities to represent clusters of stars rather than individual stars.”
Cloud-scale Molecular Gas Properties in 15 Nearby Galaxies (2018, background): “Theoretical works by McKee & Zweibel (1992), Krumholz & McKee (2005), Padoan & Nordlund (2011), Federrath & Klessen (2012), Kruijssen (2012), Krumholz et al. (2012), Hennebelle & Chabrier (2013), and Padoan et al. (2017) predict that αvir plays an important role in determining the ability of a…”
Physical Processes in the Interstellar Medium (2014, background): “…likely to be gravitationally bound, since MJ ∝ n−1/2, and so the result of an increase in the Mach number of the turbulence will typically be an increase in the star formation rate of the gas (Krumholz & McKee, 2005; Padoan & Nordlund, 2011; Hennebelle & Chabrier, 2011; Federrath & Klessen, 2012).”
Fluctuating feedback-regulated escape fraction of ionizing radiation in low-mass, high-redshift galaxies (2017, methodology): “The exact formulae are given in Federrath & Klessen (2012), using their multi-scale model based on Padoan & Nordlund (2011), coined ‘multi-ff PN’ model.”
A UNIVERSAL, LOCAL STAR FORMATION LAW IN GALACTIC CLOUDS, NEARBY GALAXIES, HIGH-REDSHIFT DISKS, AND STARBURSTS (2011, neutral): “Padoan & Nordlund (2011) argue for a slightly different functional dependence of 5 For simplicity throughout this paper we will adopt fH2 = 1, and where possible we will compare only to molecular gas masses.”
Variations in the Galactic star formation rate and density thresholds for star formation (2012, background): “Theorists have wrestled with this before (e.g. Krumholz & McKee 2005; Padoan & Nordlund 2011; Krumholz et al. 2012) and we are currently seeking to test these scenarios.”
On the diversity and statistical properties of protostellar discs (2018, background): “Magnetic pressure support can slow down the star formation rate by factors of 2–3 compared to hydrodynamical calculations (Price & Bate 2008, 2009; Wang et al. 2010; Padoan & Nordlund 2011; Federrath & Klessen 2012; Myers et al. 2014; Federrath 2015), but its affect on disc properties is unclear.”
Dense gas in the Galactic central molecular zone is warm and heated by turbulence (2015, background): “…of star formation now invoke turbulence to provide the core fragmentation spectrum, so the thermal Jeans scale is less relevant for setting core masses (Krumholz & McKee 2005; Hennebelle & Chabrier 2011; Padoan & Nordlund 2011; Federrath & Klessen 2012; Hennebelle & Chabrier 2013; Hopkins 2013).”
The exciting lives of giant molecular clouds (2013, background): “The relatively low value is thought to be due to stellar feedback, which changes the dynamics and disrupts GMCs (Dobbs et al. 2011a; Vázquez-Semadeni et al. 2010) and/or magnetic fields (Price & Bate 2008; Padoan & Nordlund 2011).”
Before the first supernova: combined effects of H II regions and winds on molecular clouds (2014, positive): “Numerous recent studies (e.g Price & Bate 2009; Wang et al. 2010; Vázquez-Semadeni et al. 2011; Padoan & Nordlund 2011; Peters et al. 2011; Federrath & Klessen 2012; Myers et al. 2014) have found that the support provided at intermediate and large scales by magnetic fields slows star formation…”
A sub-parsec resolution simulation of the Milky Way: global structure of the interstellar medium and properties of molecular clouds (2013, background): “…al. 2013), recent works showed that turbulence is the most important factor, while magnetic fields have a more moderate but still significant influence on the star formation efficiency and the dense gas mass fraction (Padoan & Nordlund 2011; Federrath & Klessen 2012, 2013; Kainulainen et al. 2013).”
The difficulty of getting high escape fractions of ionizing photons from high-redshift galaxies: A view from the FIRE cosmological simulations (2015, background): “It is also motivated by much higher-resolution, direct simulations of dense, star-forming clouds (Padoan & Nordlund 2011; Vázquez-Semadeni et al. 2011; Federrath et al. 2011).”