Velocity dispersion in the interstellar medium of early galaxies

Abstract

We study the structure of spatially resolved, line-of-sight velocity dispersion for galaxies in the Epoch of Reionization (EoR) traced by [CII] $158\mu \mathrm{m}$ line emission. Our laboratory is a simulated prototypical Lyman-break galaxy, "Freesia", part of the SERRA suite. The analysis encompasses the redshift range 6 < z < 8, when Freesia is in a very active assembling phase. We build velocity dispersion maps for three dynamically distinct evolutionary stages (Spiral Disk at z=7.4, Merger at z=8.0, and Disturbed Disk at z=6.5) using [CII] hyperspectral data cubes. We find that, at a high spatial resolution of 0.005" ($\simeq 30pc$), the luminosity-weighted average velocity dispersion is ${\sigma }_{\mathrm{CII}}$~23-38 km/s with the highest value belonging to the highly-structured Disturbed Disk stage. Low resolution observations tend to overestimate ${\sigma }_{\mathrm{CII}}$ values due to beam smearing effects that depend on the specific galaxy structure. For an angular resolution of 0.02" (0.1"), the average velocity dispersion is 16-34% (52-115%) larger than the actual one. The [CII] emitting gas in Freesia has a Toomre parameter $\mathcal{Q}$~0.2 and a rotational-to-dispersion ratio of $v_{\mathrm{c}}/\sigma$~ 7 similar to that observed in z=2-3 galaxies. The primary energy source for the velocity dispersion is due to gravitational processes, such as merging/accretion events; energy input from stellar feedback is generally subdominant (< 10%). Finally, we find that the resolved ${\sigma }_{\mathrm{CII}}-{\Sigma }_{\mathrm{SFR}}$ relation is relatively flat for $0.02<{\Sigma }_{\mathrm{SFR}}/{\mathrm{M}}_{\odot }{\mathrm{yr}}^{-1}{\mathrm{k}pc}^{-2}<30$, with the majority of data lying on the derived analytical relation $\sigma \propto {\Sigma }_{\mathrm{SFR}}^{5/7}$. At high SFR, the increased contribution from stellar feedback steepens the relation, and ${\sigma }_{\mathrm{CII}}$ rises slightly.

arXiv commentAccepted for publication in MNRAS; 16 pages (plus appendix), 8 figures, 3 tables

References in corpus (98)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The chemical composition of the Sun
• On the variation of the Initial Mass Function
• Planck 2013 results. XVI. Cosmological parameters
• The Global Schmidt Law in Star Forming Galaxies
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation
• The SINS survey: SINFONI Integral Field Spectroscopy of z ~ 2 Star-forming Galaxies
• A General Theory of Turbulence-Regulated Star Formation, From Spirals to ULIRGs
• Multi-scale initial conditions for cosmological simulations
• Radiation Pressure Supported Starburst Disks and AGN Fueling
• The SINS survey of z~2 galaxy kinematics: properties of the giant star forming clumps
• The Resolved Properties of Extragalactic Giant Molecular Clouds
• The Energy Dissipation Rate of Supersonic, Magnetohydrodynamic Turbulence in Molecular Clouds
• The Star Formation Rate and Gas Surface Density Relation in the Milky Way: Implications for Extragalactic Studies
• Towards a complete accounting of energy and momentum from stellar feedback in galaxy formation simulations
• Self-Regulated Star Formation in Galaxies via Momentum Input from Massive Stars
• The rapid formation a large rotating disk galaxy three billion years after the Big Bang
• The Interstellar Medium In Galaxies Seen A Billion Years After The Big Bang
• The Star Formation Rate of Supersonic MHD Turbulence
• Cusp-core transformations in dwarf galaxies: observational predictions
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• Star Formation Efficiencies and Lifetimes of Giant Molecular Clouds in the Milky Way
• The Kiloparsec-Scale Kinematics of High-Redshift Star-Forming Galaxies
• Maximally Star-Forming Galactic Disks I. Starburst Regulation Via Feedback-Driven Turbulence
• RAMSES-RT: Radiation hydrodynamics in the cosmological context
• Early Metal Enrichment of the Intergalactic Medium by Pregalactic Outflows
• Accretion-Driven Turbulence as Universal Process: Galaxies, Molecular Clouds, and Protostellar Disks
• Supernova Feedback in an Inhomogeneous Interstellar Medium
• The ISM in distant star-forming galaxies: Turbulent pressure, fragmentation and cloud scaling relations in a dense gas disk at z=2.3
• KROME - a package to embed chemistry in astrophysical simulations
• How stellar feedback simultaneously regulates star formation and drives outflows
• The SINS/zC-SINF survey of z~2 galaxy kinematics: SINFONI adaptive optics-assisted data and kiloparsec-scale emission line properties
• The assembly of "normal" galaxies at z=7 probed by ALMA
• The KMOS Redshift One Spectroscopic Survey (KROSS): Dynamical properties, gas and dark matter fractions of typical z~1 star-forming galaxies
• The supernova rate-velocity dispersion relation in the interstellar medium
• Rotation in [CII]-emitting gas in two galaxies at a redshift of 6.8
• On the interplay between star formation and feedback in galaxy formation simulations
• Evidence for a clumpy, rotating gas disk in a submillimeter galaxy at z=4
• A scheme for radiation pressure and photon diffusion with the M1 closure in RAMSES-RT
• Direct Numerical Simulation of Radiation Pressure-Driven Turbulence and Winds in Star Clusters and Galactic Disks
• On the [CII]-SFR relation in high redshift galaxies
• Evidence for strong dynamical evolution in disk galaxies through the last 11 Gyr. GHASP VIII: A local reference sample of rotating disk galaxies for high redshift studies
• Large Population of ALMA Galaxies at z>6 with Very High [OIII]88um to [CII]158um Flux Ratios: Evidence of Extremely High Ionization Parameter or PDR Deficit?
• Is Turbulence in the Interstellar Medium Driven by Feedback or Gravity? An Observational Test
• Dependence of Interstellar Turbulent Pressure on Supernova Rate
• Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies
• Kiloparsec-scale gaseous clumps and star formation at $z=5-7$
• Extended ionised and clumpy gas in a normal galaxy at z=7.1 revealed by ALMA
• Deep into the structure of the first galaxies: SERRA views
• DYNAMO I: A Sample of Ha-Luminous Galaxies with Resolved Kinematics
• Electron-Ion Recombination on Grains and Polycyclic Aromatic Hydrocarbons
• The Dawes Review 1: Kinematic studies of star-forming galaxies across cosmic time
• Zooming on the internal structure of $z\simeq 6$ galaxies
• Simulating cosmic metal enrichment by the first galaxies
• The impact of chemistry on the structure of high-z galaxies
• Accretion-Driven Turbulence and the Transition to Global Instability in Young Galaxy Disks
• A spectroscopic search for AGN activity in the reionization era
• Magnetorotationally-Driven Galactic Turbulence and the Formation of Giant Molecular Clouds
• Non-universal star formation efficiency in turbulent ISM
• Non-linear violent disc instability with high Toomre's Q in high-redshift clumpy disc galaxies
• Maximally Star-Forming Galactic Disks II. Vertically-Resolved Hydrodynamic Simulations of Starburst Regulation
• Kinematics of $z\ge 6$ galaxies from [CII] line emission
• A physical model for [CII] line emission from galaxies
• Effects of dust grains on early galaxy evolution
• 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
• Thermal and Magnetorotational Instability in the ISM: Two-Dimensional Numerical Simulations
• Probing Cosmic Dawn with Emission Lines: Predicting Infrared and Nebular Line Emission for ALMA and JWST
• Thermal-Instability-Driven Turbulent Mixing in Galactic Disks: I. Effective Mixing of Metals
• On the self-regulation of intense star-formation in galaxies at z=1-3
• CO line emission from galaxies in the Epoch of Reionization
• ALMA detection of extended [CII] emission in Himiko at z=6.6
• What controls the ionized gas turbulent motions in dwarf galaxies?
• Starbursting [O III] emitters and quiescent [C II] emitters in the reionization era
• FIR line emission from high redshift galaxies
• Resolving The Generation of Starburst Winds in Galaxy Mergers
• Predicting FIR lines from simulated galaxies
• Molecular clouds photoevaporation and FIR line emission
• Swirls of FIRE: Spatially Resolved Gas Velocity Dispersions and Star Formation Rates in FIRE-2 Disk Environments
• The SAMI Galaxy Survey: energy sources of the turbulent velocity dispersion in spatially-resolved local star-forming galaxies
• The Photometric and Kinematic Structure of Face-On Disk Galaxies. I. Sample Definition, H-alpha Integral Field Spectroscopy, and HI Line-Widths
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• A Simple Non-equilibrium Feedback Model for Galaxy-Scale Star Formation: Delayed Feedback and SFR Scatter
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• Galaxy Formation Through Filamentary Accretion at z=6.1
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• H2 chemistry in galaxy simulations: an improved supernova feedback model
• Early galaxy formation and its large-scale effects

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