The ALMA-CRISTAL Survey: Complex kinematics of the galaxies at the end of the Reionization Era

Abstract

The history of gas assembly in early galaxies is reflected in their complex kinematics. While a considerable fraction of galaxies at z~5 are consistent with rotating disks, current studies indicate that the dominant galaxy assembly mechanism corresponds to mergers. Despite the important progress, the dynamical classification of galaxies at these epochs is still limited by observations' resolution. We present a detailed morphological and kinematic analysis of the far-infrared bright main sequence galaxy HZ10 at z=5.65, making use of new high-resolution ($\lesssim 0.3$") [CII] 158$\mu$m ALMA and rest-frame optical JWST/NIRSpec observations. These observations reveal a previously unresolved complex morphology and kinematics of the HZ10. We confirm that HZ10 is not a single galaxy but consists of at least three components in close projected separation along the east-to-west direction. We find a [CII] bright central component (C), separated by 1.5 and 4 kpc from the east (E) and west (W) components, respectively. Our [CII] observations resolve the HZ10-C component resulting in a velocity gradient, produced by either rotation or a close-in merger. We test the rotating disk possibility using DysmalPy kinematic modeling and propose three dynamical scenarios for the HZ10 system: (i) a double merger, in which the companion galaxy HZ10-W merges with the disturbed clumpy rotation disk formed by the HZ10-C and E components; (ii) a triple merger, where the companion galaxies, HZ10-W and HZ10-E, merge with the rotation disk HZ10-C; and (iii) a quadruple merger, in which the companion galaxies HZ10-W and HZ10-E merge with the close double merger HZ10-C. Comparing [CII] with JWST/NIRSpec data, we find that [CII] emission closely resembles the broad [OIII] 5007Å emission. The latter reflects the interacting nature of the system and suggests that ionized and neutral gas phases in HZ10 are well mixed.

arXiv commentSubmitted to A&A, 16 pages, 17 figures, 1 table

References in corpus (64)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Structure of Cold Dark Matter Halos
• The Gaia mission
• THINGS: The HI Nearby Galaxy Survey
• The Interstellar Medium In Galaxies Seen A Billion Years After The Big Bang
• Little Things
• A Herschel [CII] Galactic plane survey I: the global distribution of ISM gas components
• The realm of the galaxy protoclusters
• The SINS survey: modeling the dynamics of z~2 galaxies and the high-z Tully-Fisher relation
• FIGGS: Faint Irregular Galaxies GMRT Survey - Overview, observations and first results
• The Dawes Review 9: The role of cold gas stripping on the star formation quenching of satellite galaxies
• Rotation in [CII]-emitting gas in two galaxies at a redshift of 6.8
• Reionization Era Bright Emission Line Survey: Selection and Characterization of Luminous Interstellar Medium Reservoirs in the z>6.5 Universe
• An extreme proto-cluster of luminous dusty starbursts in the early Universe
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• Collisional Excitation of the [CII] Fine Structure Transition in Interstellar Clouds
• ALMA uncovers the [CII] emission and warm dust continuum in a z = 8.31 Lyman break galaxy
• The ALPINE-ALMA [CII] Survey: Size of Individual Star-Forming Galaxies at z=4-6 and their Extended Halo Structure
• First Identification of 10-kpc Scale [CII] 158um Halos around Star-Forming Galaxies at z=5-7
• Zooming on the internal structure of $z\simeq 6$ galaxies
• How well can we Measure the Intrinsic Velocity Dispersion of Distant Disk Galaxies?
• Environment, Ram Pressure, and Shell Formation in HoII
• KMOS^3D: Dynamical constraints on the mass budget in early star-forming disks
• The Nuclear Gas Dynamics and Star Formation of NGC 7469
• Falling outer rotation curves of star-forming galaxies at 0.6 < z < 2.6 probed with KMOS^3D and SINS/ZC-SINF
• Kinematics of $z\ge 6$ galaxies from [CII] line emission
• A physical model for [CII] line emission from galaxies
• Lyman Alpha Emitters at Redshift 5.7 in the COSMOS Field
• SIGAME simulations of the [CII], [OI] and [OIII] line emission from star forming galaxies at z ~ 6
• The Nuclear Gas Dynamics and Star Formation of Markarian 231
• Lyα Emission from High Redshift Sources in COSMOS
• Hidden in plain sight: a massive, dusty starburst in a galaxy protocluster at z=5.7 in the COSMOS field
• The ALPINE-ALMA [CII] Survey: Kinematic Diversity & Rotation in Massive Star Forming Galaxies at z~4.4-5.9
• ALMA Reveals Weak [NII] Emission in "Typical" Galaxies and Intense Starbursts at z=5-6
• The Multiple Merger Assembly of a Hyper-luminous Obscured Quasar at redshift 4.6
• Outflows and extended [CII] halos in high redshift galaxies
• Dynamical characterization of galaxies up to $z\sim 7$
• The ALPINE-ALMA [CII] survey: The contribution of major mergers to the galaxy mass assembly at z~5
• ALMA reveals extended cool gas and hot ionized outflows in a typical star-forming galaxy at $z=7.13$
• 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?
• Low star formation efficiency in typical galaxies at z=5-6
• Kiloparsec view of a typical star-forming galaxy when the Universe was $\sim$1 Gyr old II. Regular rotating disk and evidence for baryon dominance on galactic scales
• MHONGOOSE -- A MeerKAT Nearby Galaxy HI Survey
• Structure and kinematics of a massive galaxy at z ~ 7
• PyAutoFit: A Classy Probabilistic Programming Language for Model Composition and Fitting
• Comparing [CII], HI, and CO dynamics of nearby galaxies
• Early JWST imaging reveals strong optical and NIR color gradients in galaxies at $z\sim 2$ driven mostly by dust
• Ultra-Red Galaxies Signpost Candidate Proto-Clusters at High Redshift
• The ALMA-ALPAKA survey II. Evolution of turbulence in galaxy disks across cosmic time: difference between cold and warm gas
• The ALMA-CRISTAL survey: Widespread dust-obscured star formation in typical star-forming galaxies at z=4-6
• GA-NIFS: Multi-phase analysis of a star-forming galaxy at $z\sim 5.5$
• 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
• VERTICO IV: Environmental Effects on the Gas Distribution and Star Formation Efficiency of Virgo Cluster Spirals
• The ALMA-CRISTAL Survey: Spatial extent of [CII] line emission in star-forming galaxies at $z=4-6$
• A hidden active galactic nucleus powering bright [O III] nebulae in a protocluster at $z=4.5$ revealed by JWST
• The ALMA-CRISTAL survey. Discovery of a 15 kpc-long gas plume in a $z=4.54$ Lyman-$\alpha$ blob
• The most distant HI galaxies discovered by the 500 m dish FAST
• Detection of HI 21 cm emission from a strongly lensed galaxy at z~1.3
• The interstellar medium of high-redshift galaxies: Gathering clues from C III] and [C II] lines
• The ALMA-CRISTAL survey: Dust temperature and physical conditions of the interstellar medium in a typical galaxy at z=5.66
• Tomography of the environment of the COSMOS/AzTEC-3 submillimeter galaxy at z=5.3 revealed by Lyalpha and MUSE observations
• Molecular Gas Excitation of the Massive Dusty Starburst CRLE and the Main-Sequence Galaxy HZ10 at z=5.7 in the COSMOS Field