UV regulated star formation in high-redshift galaxies

Abstract

The first galaxies forming a few hundred million years after the Big Bang are the key drivers of cosmic evolution and ideal laboratories to study theories of galaxy formation. We here study the role of UV radiation in suppressing star formation in primordial galaxies by destroying molecular hydrogen, the main coolant in primordial gas and provide estimates of cold dense gas at the onset of star formation. To accomplish this goal, we perform three dimensional cosmological simulations of minihalos in different environments forming at $z\sim 25$ by varying strength of background UV flux below the Lyman limit between 0.01-1000 in units of ${\mathrm{J}}_{21}=10^{-21}erg/c{\mathrm{m}}^2/s/Hz/sr$. Particularly, we include photo-detachment of ${\mathrm{H}}^{-}$, the self-shielding of ${\mathrm{H}}_2$ which both were neglected in previous studies and use updated reaction rates. Our results show that depending on the background level ${\mathrm{H}}_2$ formation is suppressed, delaying gravitational collapse until halos reach the atomic cooling limit. We find that the formation of cold dense molecular gas and subsequently star formation gets delayed by 100 to 230 Myr depending on the level of the background radiation and the growth history of the dark matter halos. The fraction of dense self-shielded gas is a strong function of the background flux and exponentially declines with the strength of incident UV flux above ${\mathrm{J}}_{21}\ge 1$. We find that taking into account ${\mathrm{H}}_2$ self-shielding is crucial for accurately estimating the amount of cold dense gas available for star formation.

Accepted for publication in MNRAS, comments are welcome

References in corpus (21)

• Protostar Formation in the Early Universe
• The Formation of Population III Binaries from Cosmological Initial Conditions
• The Relation Between SFR and Stellar Mass for Galaxies at 3.5 $\le z\le$ 6.5 in CANDELS
• Resolving the Formation of Protogalaxies. III. Feedback from the First Stars
• Star formation at very low metallicity. I: Chemistry and cooling at low densities
• The Birth of a Galaxy. II. The Role of Radiation Pressure
• The critical radiation intensity for direct collapse black hole formation: dependence on the radiation spectral shape
• Direct collapse black hole formation from synchronized pairs of atomic cooling halos
• Occurrence of Metal-free Galaxies in the Early Universe
• How realistic UV spectra and X-rays suppress the abundance of direct collapse black holes
• The Influence of Streaming Velocities on the Formation of the First Stars
• A UV flux constraint on the formation of direct collapse black holes
• The Transition from the First Stars to the Second Stars in the Early Universe
• Revised rate coefficients for H${}_2$ and H${}^{-}$ destruction by realistic stellar spectra
• Disk fragmentation and the formation of population III stars
• CO Multi-line Imaging of Nearby Galaxies (COMING): VI. Radial variations in star formation efficiency
• Formation of carbon-enhanced metal-poor stars in the presence of far ultraviolet radiation
• Optimal neighbourhood to nurture giants: a fundamental link between star forming galaxies and direct collapse black holes
• Star Formation Efficiencies at Giant Molecular Cloud Scales in the Molecular Disk of the Elliptical Galaxy NGC 5128 (Centaurus A)
• Extreme Primordial Star Formation Enabled by High Redshift Quasars
• Detection of a Lensed z$\approx$11 Galaxy in the Rest-Optical with Spitzer/IRAC and the Inferred SFR, Stellar Mass, and Physical Size

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• Multi-flavour SMBH seeding and evolution in cosmological environments
• Starbursts in low-mass haloes at Cosmic Dawn. I. The critical halo mass for star formation
• Radiation Hydrodynamical Simulations of the Birth of Intermediate-Mass Black Holes in the First Galaxies
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