Dynamical characterization of galaxies up to $z\sim 7$

Abstract

The characterization of the dynamical state of galaxies up to z~7 is crucial for constraining the mechanisms driving the mass assembly in the early Universe. However, it is unclear whether the data quality of current and future observations is sufficient to perform a solid dynamical analysis. This paper defines the angular resolution and S/N required for a robust characterization of the dynamical state of galaxies up to the EoR. The final aim is to help design spatially-resolved surveys targeting emission lines of primeval galaxies. We investigate the [CII]-158um emission from z~6-7 LBGs from the SERRA cosmological simulation, covering a range of dynamical states: from disks to major mergers. We create ALMA mock observations with various data quality and apply the kinematic classification methods used in the literature. These tests allow us to quantify the performances of such methods as a function of angular resolution and S/N. We find that barely-resolved observations do not allow the correct dynamical characterization of a galaxy, resulting in the misclassification of all disks in our sample. However, even when using spatially-resolved observations with data quality typical of high-z galaxies, the standard kinematic classification methods, based on the analysis of the moment maps, fail to distinguish a merger from a disk. The high angular resolution and S/N needed to apply these standard methods successfully can be achieved with current data only for a handful of bright galaxies. We propose a new classification method, called PVsplit, that quantifies the asymmetries and morphological features in position-velocity diagrams using three empirical parameters. We test PVsplit on our mock data concluding that it can predict whether a galaxy is a disk or a merger provided that S/N $\gtrsim 10$, and the major axis is covered by $\gtrsim 3$ independent resolution elements.

Submitted to Astronomy and Astrophysics (A&A) Journal. Comments are welcome

References in corpus (32)

• The NumPy array: a structure for efficient numerical computation
• Formation of Massive Galaxies at High Redshift: Cold Streams, Clumpy Disks and Compact Spheroids
• The KMOS^3D Survey: design, first results, and the evolution of galaxy kinematics from 0.7<z<2.7
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• Rapid formation of exponential disks and bulges at high redshift from the dynamical evolution of clump cluster and chain galaxies
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• Four phases of angular-momentum buildup in high-z galaxies: from cosmic-web streams through an extended ring to disc and bulge
• Kinemetry of SINS High-Redshift Star-Forming Galaxies: Distinguishing Rotating Disks from Major Mergers
• The AIMSS Project I: Bridging the Star Cluster - Galaxy Divide
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• A dynamically cold disk galaxy in the early Universe
• The KMOS^3D Survey: data release and final survey paper
• Deep into the structure of the first galaxies: SERRA views
• A Cold, Massive, Rotating Disk Galaxy 1.5 Billion Years after the Big Bang
• Zooming on the internal structure of $z\simeq 6$ galaxies
• The impact of chemistry on the structure of high-z galaxies
• The REBELS ALMA Survey: cosmic dust temperature evolution out to z $\sim$ 7
• A massive stellar bulge in a regularly rotating galaxy 1.2 billion years after the Big Bang
• The KMOS Redshift One Spectroscopic Survey (KROSS): the origin of disk turbulence in z~0.9 star-forming galaxies
• Kinematics of $z\ge 6$ galaxies from [CII] line emission
• Early formation of massive, compact, spheroidal galaxies with classical profiles by violent disc instability or mergers
• The KMOS Redshift One Spectroscopic Survey (KROSS): rotational velocities and angular momentum of z~0.9 galaxies
• Fast rotating and low-turbulence discs at $z\simeq 4.5$: Dynamical evidence of their evolution into local early-type galaxies
• Major Merging History in CANDELS. I. Evolution of the Incidence of Massive Galaxy-Galaxy Pairs from z=3 to z~0
• CO line emission from galaxies in the Epoch of Reionization
• Distinguishing Mergers and Disks in High Redshift Observations of Galaxy Kinematics
• The ALPINE-ALMA [CII] survey: The contribution of major mergers to the galaxy mass assembly at z~5
• Morpho-kinematics of z~1 galaxies probe the hierarchical scenario
• Morphological decomposition of TNG50 galaxies: methodology and catalogue
• Photoevaporation of Jeans-unstable molecular clumps
• A low HI column density filament in NGC 2403: signature of interaction or accretion
• Galaxy Formation Through Filamentary Accretion at z=6.1

Cited by in corpus (32)

• Regular rotation and low turbulence in a diverse sample of z ~ 4.5 galaxies observed with ALMA
• The rapid onset of stellar bars in the baryon-dominated centers of disk galaxies
• The gas and stellar content of a metal-poor galaxy at $z=8.496$ as revealed by JWST and ALMA
• The ALMA-ALPAKA survey I: high-resolution CO and [CI] kinematics of star-forming galaxies at z = 0.5-3.5
• Dynamically cold disks in the early Universe: myth or reality?
• ALMA hints at the presence of turbulent disk galaxies at z > 5
• GA-NIFS: Early-stage feedback in a heavily obscured AGN at $z=4.76$
• Structure and kinematics of a massive galaxy at z ~ 7
• The ALMA-ALPAKA survey II. Evolution of turbulence in galaxy disks across cosmic time: difference between cold and warm gas
• ALMA reveals a stable rotating gas disk in a paradoxical low-mass, ultra-dusty galaxy at z = 4.274
• [CII] halos in ALPINE galaxies: smoking-gun of galactic outflows?
• The ALMA-CRISTAL survey: Gas, dust, and stars in star-forming galaxies when the Universe was ~1 Gyr old I. Survey overview and case studies
• KURVS: The outer rotation curve shapes and dark matter fractions of $z\sim 1.5$ star-forming galaxies
• The ALMA REBELS Survey: Discovery of a massive, highly star-forming and morphologically complex ULIRG at $z=7.31$
• The mass-metallicity relation as a ruler for galaxy evolution: insights from the James Webb Space Telescope
• Interpreting ALMA non-detections of JWST super-early galaxies
• JWST's PEARLS: resolved study of the stellar and dust components in starburst galaxies at cosmic noon
• Dynamical modelling and origin of gas turbulence in z $\sim$ 4.5 galaxies
• Kinematic analysis of $\mathbf{z}=4.3$ galaxies in the SPT2349$-$56 protocluster core
• Infrared fine-structure lines at high redshift
• Spatially resolved [CII]-gas conversion factor in early galaxies
• The ALMA-CRISTAL survey: Extended [CII] emission in an interacting galaxy system at z ~ 5.5
• Turbulent gas-rich discs at high redshift: origin of thick stellar discs through 3D 'baryon sloshing'
• The ALMA-CRISTAL Survey: Complex kinematics of the galaxies at the end of the Reionization Era
• Central concentration of warm and dense molecular gas in a strongly lensed submillimeter galaxy at z=6
• Kinematic scaling relations of disc galaxies from ionised gas at $z\sim 1$ and their connection with dark matter haloes
• Amaryllis: a digital twin of the earliest galaxies in the Universe
• An optically-dark merging system at z~6 detected by JWST
• A Shallow Slope for the Stellar Mass--Angular Momentum Relation of Star-Forming Galaxies at $1.5<z<2.5$
• Observational biases on rotation curves from IFU data at cosmic noon
• Investigating the role of turbulence in the interstellar medium in $z\sim 3$ dusty star-forming galaxies using kpc-resolution ALMA dust and gas maps
• Spatially non-parametric recovery of intrinsic kinematic maps in pre- to post-merger galaxies