Zooming on the internal structure of $z\simeq 6$ galaxies

Abstract

We present zoom-in, AMR, high-resolution ($\simeq 30$ pc) simulations of high-redshift ($z\simeq 6$) galaxies with the aim of characterizing their internal properties and interstellar medium. Among other features, we adopt a star formation model based on a physically-sound molecular hydrogen prescription, and introduce a novel scheme for supernova feedback, stellar winds and dust-mediated radiation pressure. In the zoom-in simulation the target halo hosts "Dahlia", a galaxy with a stellar mass $M_{\ast }=1.6\times 10^{10}$M${}_{\odot }$, representative of a typical $z\sim 6$ Lyman Break Galaxy. Dahlia has a total H2 mass of $10^{8.5}$M${}_{\odot }$, that is mainly concentrated in a disk-like structure of effective radius $\simeq 0.6$ kpc and scale height $\simeq 200$ pc. Frequent mergers drive fresh gas towards the center of the disk, sustaining a star formation rate per unit area of $\simeq 15$M${}_{\odot }$ yr${}^{-1}$ kpc${}^{-2}$. The disk is composed by dense ($n\gtrsim 25$ cm${}^{-3}$), metal-rich ($Z\simeq 0.5$ Z${}_{\odot }$) gas, that is pressure-supported by radiation. We compute the $158\mu$m [CII] emission arising from {Dahlia}, and find that $\simeq 95\%$ of the total [CII] luminosity ($L_{[CII]}\simeq 10^{7.5}$ L${}_{\odot }$) arises from the H2 disk. Although $30\%$ of the CII mass is transported out of the disk by outflows, such gas negligibly contributes to [CII] emission, due to its low density ($n\lesssim 10$ cm${}^{-3}$) and metallicity ($Z\lesssim 10^{-1}$Z${}_{\odot }$). Dahlia is under-luminous with respect to the local [CII]-SFR relation; however, its luminosity is consistent with upper limits derived for most $z\sim 6$ galaxies.

21 pages, 11 figures, 3 tables

References in corpus (35)

• Cosmic Star Formation History
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Star Formation and Feedback in Smoothed Particle Hydrodynamic Simulations--I. Isolated Galaxies
• The Atomic to Molecular Transition in Galaxies. II: HI and H_2 Column Densities
• The 2013 Release of Cloudy
• Momentum Injection by Supernovae in the Interstellar Medium
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• On the onset of galactic winds in quiescent star forming galaxies
• The Dynamics of Radiation Pressure-Dominated HII Regions
• The Atomic to Molecular Transition in Galaxies. I: An Analytic Approximation for Photodissociation Fronts in Finite Clouds
• On the interplay between star formation and feedback in galaxy formation simulations
• Very extended cold gas, star formation and outflows in the halo of a bright QSO at z>6
• The Birth of a Galaxy. II. The Role of Radiation Pressure
• A simple multigrid scheme for solving the Poisson equation with arbitrary domain boundaries
• Essential physics of early galaxy formation
• Star formation and the interstellar medium in z>6 UV-luminous Lyman-break galaxies
• Simulating cosmic metal enrichment by the first galaxies
• Galaxies that Shine: radiation-hydrodynamical simulations of disk galaxies
• ALMA Observation of 158 micron [CII] Line and Dust Continuum of a z=7 Normally Star-forming Galaxy in the Epoch of Reionization
• Life and times of dwarf spheroidal galaxies
• Decoding the stellar fossils of the dusty Milky Way progenitors
• Chemical Rates on Small Grains and PAHs: C^+ Recombination and H_2 Formation
• Intensity mapping of [CII] from early galaxies
• New constraints on dust emission and UV attenuation of z=6.5-7.5 galaxies from millimeter observations
• The Argo Simulation: II. The Early Build-up of the Hubble Sequence
• The H+ Region Contribution to [C II] 158 Micron Emission
• Clumpy high-z galaxies as a testbed for feedback-regulated galaxy formation
• The circumgalactic medium of high redshift galaxies
• Galactic outflow and diffuse gas properties at z>=1 using different baryonic feedback models
• Lyman Alpha and MgII as Probes of Galaxies and their Environments
• Simulating the H2 content of high-redshift galaxies
• Simulations of the non-linear thin shell instability
• A far-IR view of the starburst driven superwind in NGC 2146
• Effect of Cosmic UV Background on Star Formation in High Redshift Galaxies

Cited by in corpus (32)

• Efficient Formation of Massive Galaxies at Cosmic Dawn by Feedback-Free Starbursts
• Deep into the structure of the first galaxies: SERRA views
• Hydrodynamical simulations of the galaxy population: enduring successes and outstanding challenges
• The impact of chemistry on the structure of high-z galaxies
• Kinematics of $z\ge 6$ galaxies from [CII] line emission
• Stochastic star formation in early galaxies: JWST implications
• ALMA reveals metals yet no dust within multiple components in CR7
• SIGAME simulations of the [CII], [OI] and [OIII] line emission from star forming galaxies at z ~ 6
• A wide dispersion in star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6
• Probing Cosmic Dawn with Emission Lines: Predicting Infrared and Nebular Line Emission for ALMA and JWST
• ALMA [CII] detection of a redshift 7 lensed galaxy behind RXJ1347.1-1145
• CO line emission from galaxies in the Epoch of Reionization
• Dust temperature in ALMA $\hbox{[C $\scriptstyle\rm II $]}$-detected high-$z$ galaxies
• Quasar outflows at $z\ge 6$: the impact on the host galaxies
• The natural emergence of the correlation between H2 and star formation rate surface densities in galaxy simulations
• The ALPINE-ALMA [CII] survey: The contribution of major mergers to the galaxy mass assembly at z~5
• Impact of X-rays on CO emission from high-z galaxies
• Galactic angular momentum in cosmological zoom-in simulations. I. Disk and bulge components and the galaxy--halo connection
• Lyα emission from galaxies in the Epoch of Reionization
• The effect of non-equilibrium metal cooling on the interstellar medium
• Two Modes of LyC Escape From Bursty Star Formation: Implications for [C II] Deficits and the Sources of Reionization
• Galaxy Formation Through Filamentary Accretion at z=6.1
• The stellar populations of high-redshift dwarf galaxies
• Molecular clumps photoevaporation in ionized regions
• Dust masses of $z>5$ galaxies from SED fitting and ALMA upper limits
• Constraint on dust evolution processes in normal galaxies at $z>6$ detected by ALMA
• Diagnosing the interstellar medium of galaxies with far-infrared emission lines I. The [C II] 158 microns line at z~0
• Radiation-pressure-driven dust transport to galaxy halos at $z\sim 10$
• Evidence for extended gaseous reservoirs around AGN at cosmic noon from ALMA CO(3-2) observations
• Lyman-alpha radiation pressure: an analytical exploration
• Emergence of Galactic Morphologies at Cosmic Dawn: Input from Numerical Modeling
• Galaxies into the Dark Ages