@article{eb7aab01d0704107ad2d973843eb80b6,
title = "Self-consistent proto-globular cluster formation in cosmological simulations of high-redshift galaxies",
abstract = "We report the formation of bound star clusters in a sample of high-resolution cosmological zoom-in simulations of z ≥ 5 galaxies from the Feedback In Realistic Environments project. We find that bound clusters preferentially form in high-pressure clouds with gas surface densities over 104M⊙ pc-2, where the cloud-scale star formation efficiency is near unity and young stars born in these regions are gravitationally bound at birth. These high-pressure clouds are compressed by feedback-driven winds and/or collisions of smaller clouds/gas streams in highly gas-rich, turbulent environments. The newly formed clusters follow a power-law mass function of dN/dM ~ M-2. The cluster formation efficiency is similar across galaxies with stellarmasses of~107-1010M⊙ at z ≥ 5. The age spread of cluster stars is typically a few Myr and increases with cluster mass. The metallicity dispersion of cluster members is ~0.08 dex in [Z/H] and does not depend on clustermass significantly. Our findings support the scenario that present-day old globular clusters (GCs) were formed during relatively normal star formation in high-redshift galaxies. Simulations with a stricter/looser star formation model form a factor of a few more/fewer bound clusters per stellar mass formed, while the shape of the mass function is unchanged. Simulations with a lower local star formation efficiency form more stars in bound clusters. The simulated clusters are larger than observed GCs due to finite resolution. Our simulations are among the first cosmological simulations that form bound clusters self-consistently in a wide range of high-redshift galaxies.",
keywords = "Cosmology: theory, Galaxies: evolution, Galaxies: formation, Galaxies: high-redshift, Star clusters: general",
author = "Xiangcheng Ma and Grudi{\'c}, {Michael Y.} and Eliot Quataert and Hopkins, {Philip F.} and Faucher-Giguere, {Claude Andr{\'e}} and Michael Boylan-Kolchin and Andrew Wetzel and Kim, {Ji Hoon} and Norman Murray and Du{\v s}an Kere{\v s}",
note = "Funding Information: We acknowledge our referee, Oleg Gnedin, for a constructive report that helps us correct a few errors and inaccurate statements and improve the clarity of this paper. We also thank many colleagues, especially Paul Shapiro and Hui Li, for sending us helpful comments and discussions after this paper appeared on arXiv. The simulations used in this paper were run on XSEDE computational resources (allocations TG-AST120025, TG-AST130039, TG-AST140023, TG-AST140064, and TG-AST190028). This work was supported in part by a Simons Investigator Award from the Simons Foundation (EQ) and by NSF grant AST-1715070. EQ thanks the Princeton Astrophysical Sciences department and the theoretical astrophysics group and Moore Distinguished Scholar program at Caltech for their hospitality and support. MG and PFH were supported by an Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, and NSF Collaborative Research Grant #1411920 and CAREER grant #1455342. CAFG was supported by NSF through grants AST-1517491, AST-1715216, and CAREER award AST-1652522, by NASA through grant 17-ATP17-0067, by STScI through grant HST-GO-14681.011, and by a Cottrell Scholar Award from the Research Corporation for Science Advancement. MBK acknowledges support from NSF grant AST-1517226 and CAREER grant AST-1752913 and from NASA grants NNX17AG29G and HST-AR-14282, HST-AR-14554, HST-AR-15006, and HST-GO-14191 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. AW was supported by NASA, through ATP grant 80NSSC18K1097 and HST grants GO-14734 and AR-15057 from STScI. DK was supported by NSF grant AST-1715101 and the Cottrell Scholar Award from the Research Corporation for Science Advancement. Funding Information: We acknowledge our referee, Oleg Gnedin, for a constructive report that helps us correct a few errors and inaccurate statements and improve the clarity of this paper. We also thank many colleagues, especially Paul Shapiro and Hui Li, for sending us helpful comments and discussions after this paper appeared on arXiv. The simulations used in this paper were run on XSEDE computational resources (allocations TG-AST120025, TG-AST130039, TG-AST140023, TG-AST140064, and TG-AST190028). Thisworkwas supported in part by a Simons Investigator Award from the Simons Foundation (EQ) and by NSF grant AST-1715070. EQ thanks the Princeton Astrophysical Sciences department and the theoretical astrophysics group andMooreDistinguished Scholar program at Caltech for their hospitality and support. MG and PFH were supported by an Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, and NSF Collaborative Research Grant #1411920 and CAREER grant #1455342. CAFG was supported by NSF through grants AST-1517491, AST-1715216, and CAREER award AST-1652522, by NASA through grant 17-ATP17-0067, by STScI through grant HST-GO-14681.011, and by a Cottrell Scholar Award from the Research Corporation for Science Advancement.MBK acknowledges support from NSF grant AST-1517226 and CAREER grant AST- 1752913 and from NASA grants NNX17AG29G and HST-AR- 14282, HST-AR-14554, HST-AR-15006, and HST-GO-14191 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. AW was supported by NASA, through ATP grant 80NSSC18K1097 and HST grants GO- 14734 and AR-15057 from STScI. DK was supported by NSF grant AST-1715101 and the Cottrell Scholar Award from the Research Corporation for Science Advancement. Publisher Copyright: {\textcopyright} 2020 The Author(s).",
year = "2020",
month = apr,
day = "1",
doi = "10.1093/mnras/staa527",
language = "English (US)",
volume = "493",
pages = "4315--4332",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "3",
}