Early galaxy evolution: The complex interstellar medium distribution of the z∼7 galaxy A1689-zD1
Journal article, 2025
We observed the gravitationally lensed (_ = 9:6 _ 0:19) galaxy A1689-zD1 at z = 7:1 in bands 3, 6, and 8 of the Atacama Large Millimeter/submillimeter Array. These high-resolution observations (_200 pc) enabled us to separate the source into five components in the [C ii] 158 _m and [O iii] 88 _m emission lines within a projected distance of 2 kpc. Even though these components appear to vary strongly from one another in both their line, continuum, and optical characteristics, the assembly of components do not show ordered rotation and appear consistent with simulations of a galaxy system undergoing the process of assembly. The total dynamical mass of the galaxy (2_1010 M_) is an order of magnitude larger than the spectrally estimated stellar mass, suggesting a near-complete optical obscuration of the bulk of the stellar component. Comparing the line ratios as well as the line properties to other properties such as the star formation rate, we find that A1689-zD1 is consistent with the relations derived from local star-forming galaxies. Even though A1689-zD1 lies on local star formation scaling relations and has a high dust and stellar mass estimate, the kinematics suggest it is in an early assembly stage, which could lead to it becoming a disk galaxy at a later stage.
Galaxies: individual: A1689-zD1
Submillimeter: galaxies
Galaxies: ISM
Galaxies: evolution
Galaxies: high-redshift
Author
Kirsten Knudsen
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
D. Watson
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
J. Richard
Université de Lyon
D. Frayer
Green Bank Observatory
S. Fujimoto
Cosmic Dawn Center (DAWN)
Niels Bohr Institute
University of Texas
Hollis B. Akins
University of Texas
Cosmic Dawn Center (DAWN)
Niels Bohr Institute
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Nina Bonaventura
Cosmic Dawn Center (DAWN)
Niels Bohr Institute
G. Brammer
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
L. Christensen
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
Takuya Hashimoto
University of Tsukuba
Akio K. Inoue
Waseda University
Hiroshi Matsuo
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
MichaÅ J. MichaåÂowski
Adam Mickiewicz University in Poznań
J. A. Zavala
National Astronomical Observatory of Japan
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 701 A85Galaxy evolution: Tracing the gas fraction of star-forming galaxies
Swedish Research Council (VR) (2015-05580), 2016-01-01 -- 2019-12-31.
Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Astronomy, Astrophysics, and Cosmology
DOI
10.1051/0004-6361/202453229