SIMULATIONS ON A MOVING MESH: THE CLUSTERED FORMATION OF POPULATION III PROTOSTARS

By Thomas Greif, Volker Springel, Simon D. M. White, S. Glover, P. C. Clark, Rowan J. Smith, Ralf Klessen, Volker Bromm. 2011

336 citations recorded by the source corpus.

The cosmic dark ages ended a few hundred million years after the big bang, when the first stars began to fill the universe with new light. It has generally been argued that these stars formed in isolation and were extremely massive—perhaps 100 times as massive as the Sun. In a recent study, Clark and collaborators showed that this picture requires revision. They demonstrated that the accretion disks that build up around Population III stars are strongly susceptible to fragmentation and that the first stars should therefore form in clusters rather than in isolation. We here use a series of high-resolution hydrodynamical simulations performed with the moving mesh code AREPO to follow up on this proposal and to study the influence of environmental parameters on the level of fragmentation. We model the collapse of five independent minihalos from cosmological initial conditions, through the runaway condensation of their central gas clouds, to the formation of the first protostar, and beyond for a further 1000 years. During this latter accretion phase, we represent the optically thick regions of protostars by sink particles. Gas accumulates rapidly in the circumstellar disk around the first protostar, fragmenting vigorously to produce a small group of protostars. After an initial burst, gravitational instability recurs periodically, forming additional protostars with masses ranging from ∼0.1 to 10 M☉. Although the shape, multiplicity, and normalization of the protostellar mass function depend on the details of the sink-particle algorithm, fragmentation into protostars with diverse masses occurs in all cases, confirming earlier reports of Population III stars forming in clusters. Depending on the efficiency of later accretion and merging, Population III stars may enter the main sequence in clusters and with much more diverse masses than are commonly assumed.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/572b9bae8f280ba57b7ffab148229674679dc06f

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

Citations in the corpus

The birth of a galaxy – III. Propelling reionization with the faintest galaxies (2014, methodology): “On a similar topic, we used a characteristic mass of 100 M for our Pop III IMF, which is somewhat higher than recent Pop III star formation simulations that find characteristic masses around tens of M (Turk, Abel & O’Shea 2009; Stacy, Greif & Bromm 2010; Greif et al. 2011b, 2012; Susa 2013).”
Ubiquitous seeding of supermassive black holes by direct collapse (2012, background): “As per our current understanding, Pop III stars form in (at most) groups of a few with masses∼ few tens of solar masses (e.g. Greif et al. 2011).”
THE MASS SPECTRUM OF THE FIRST STARS (2014, background): “They found that a “cluster” of lower mass stars could form, rather than a single very massive star (Clark et al. 2011a, 2011b; Greif et al. 2011, 2012; Machida & Doi 2013).”
The Evolution of the Intergalactic Medium (2015, background): “Such small star formation rates are insufficient to ionize but a small fraction of the then neutral IGM, even for a top-heavy stellar population that simulations find is most likely (Abel, Bryan & Norman 2002; Greif et al. 2011).”
Shocking results without shocks: Subsonic turbulence in smoothed particle hydrodynamics and moving-mesh simulations (2011, methodology): “We note that the AREPO code has recently been successfully used in first science applications, studying first star formation (Greif et al. 2011) and galaxy formation (Vogelsberger et al. 2011).”
ONE HUNDRED FIRST STARS: PROTOSTELLAR EVOLUTION AND THE FINAL MASSES (2013, methodology): “Accretion Disk Fragmentation Recently, Clark et al. (2011) and Greif et al. (2011) studied the evolution of primordial protostellar disks over one hundred years using sink particle techniques.”
THE SPECTRAL EVOLUTION OF THE FIRST GALAXIES. I. JAMES WEBB SPACE TELESCOPE DETECTION LIMITS AND COLOR CRITERIA FOR POPULATION III GALAXIES (2011, background): “However, this pop III.1 (∼ 100 M⊙) versus pop III.2 (∼ 10 M⊙) picture is looking increasingly uncertain, as the latest simulations indicate more fragmentation than before, with lower pop III masses as a result (e.g. Stacy et al. 2008; Clark et al. 2011; Greif et al. 2011a).”
Formation and evolution of primordial protostellar systems (2012, methodology): “We note that we do not include relative streaming velocities between the DM and the gas, which influences the virialization of the minihaloes and might have a non-negligible impact on the later evolution of the gas cloud (Greif et al. 2011b).”
The First Stars (2012, methodology): “One of the most exciting results of the Greif et al. (2011a) model is that some of the protostars that are ejected from the centre of the star-forming minihalo have masses that are below 0.8 M , and hence lifetimes that are longer than the current age of the Universe.”
THE BIRTH OF A GALAXY: PRIMORDIAL METAL ENRICHMENT AND STELLAR POPULATIONS (2010, background): “…2007; Smith et al. 2009), resulting from the CMB temperature floor, could be more prevalent, and 2) streaming gas velocities arising from the recombination epoch (Tseliakhovich & Hirata 2010) could suppress star formation in halos below 106M⊙ (Tseliakhovich et al. 2011; Greif et al. 2011b).”
CANDELS: THE CONTRIBUTION OF THE OBSERVED GALAXY POPULATION TO COSMIC REIONIZATION (2012, result): “This conclusion has been strengthened by recent simulation results which have corrected the mass scale of the first stars down to less extreme values (Clark et al. 2011; Greif et al. 2011, 2012).”
Physical Processes in the Interstellar Medium (2014, background): “Indeed, current numerical simulations provide the first hints that this might be the case (e.g. Clark et al., 2011; Greif et al., 2011; Stacy & Bromm, 2013).”
The First Billion Years project: the impact of stellar radiation on the co-evolution of Populations II and III (2012, background): “…may form from primordial gas, although the overall IMF of primordial stars is expected to be very top-heavy relative to that of Pop II stars (e.g. Greif et al. 2011). c© 2012 RAS, MNRAS 000, 000–000 much larger scales than are captured in our simulation volume – we must account for the…”
The First Stars: Mass Growth Under Protostellar Feedback (2011, methodology): “Without sink merging, the final mass reached by the main sink could have differed (see also discussion in Greif et al. 2011), and the total stellar content might not have been dominated by a massive binary.”
What drives the growth of black holes (2011, background): “…idea that the first stars are very massive, due to either fragmentation or feedback effects (e.g., Glover et al., 2008; McKee & Tan, 2008; Turk et al., 2009; Trenti & Stiavelli, 2009; Stacy et al., 2010; Greif et al., 2011), casting some doubt on the the role of Population III remnants as BH seeds.”
Primordial star formation under the influence of far ultraviolet radiation: 1540 cosmological haloes and the stellar mass distribution (2015, background): “For instance, recent 3D numerical simulations show that a circumstellar disc becomes gravitationally unstable and fragments (e.g., Clark et al. 2011; Greif et al. 2011, 2012; Stacy & Bromm 2013).”
FORMATION OF MASSIVE PRIMORDIAL STARS: INTERMITTENT UV FEEDBACK WITH EPISODIC MASS ACCRETION (2015, background): “Whereas the 2D simulations have revealed the dynamic nature of stellar UV feedback, 3D simulations show an additional aspect of mass accretion through selfgravitating circumstellar disks (e.g., Stacy et al. 2010; Clark et al. 2011; Greif et al. 2011, 2012; Vorobyov et al. 2013; Machida & Doi 2013).”