The ALMA-CRISTAL survey: Extended [CII] emission in an interacting galaxy system at z ∼ 5.5
Year: 2025
Type: article
Abstract: The ALMA [C II] Resolved Ism in STar-forming gALaxies (CRISTAL) survey is a Cycle 8 ALMA Large Program that studies the cold- gas component of high-redshift galaxies. Its subarcsecond-resolution observations are key to distinguishing physical mechanisms that shaped galaxies during cosmic dawn. In this paper, we explore the morphology and kinematics of the cold gas, star-forming, and stellar components in the star-forming main-sequence galaxy CRISTAL-05/HZ3, at z = 5.54. Our analysis includes ALMA observations at a spatial resolution of 0.3″ (∼2 kpc) of the [C II] line. While CRISTAL-05 was previously classified as a single source, our observations reveal that the system is a close interacting pair that is surrounded by an extended component of carbon-enriched gas. This is imprinted in the disturbed elongated [C II] morphology and in the separation of the two components in the position-velocity diagram (∼100 km s −1 ). The central region is composed of two components, named C05-NW and C05-SE, and the former is the dominant component. A significant fraction of [C II] arises beyond the close pair up to 10 kpc, while the regions forming new massive stars and the stellar component seem compact (r [C II] ∼4 × r UV ), as traced by rest-frame UV and optical imaging obtained with the Hubble Space Telescope and the James Webb Space Telescope. Our kinematic model, constructed using the DYSMALpy software, yields a minor contribution of dark matter of C05-NW within a radius of ∼2 × R eff . Finally, we explore the resolved [C II] /far-IR ratios as a proxy for shock-heating produced by this merger. We argue that the extended [C II] emission is mainly caused by the merger of the galaxies, which could not be discerned with lower-resolution observations. Our work emphasizes the need for high-resolution observations to fully characterize the dynamic stages of infant galaxies and the physical mechanisms that drive the metal enrichment of the circumgalactic medium.
Source: Astronomy and Astrophysics
Authors: A. Posses, M. Aravena, J. González-López, N. M. Förster Schreiber, D. Liu, L. Lee, M. Solimano, T. Díaz-Santos, R. J. Assef, L. Barcos-Muñoz, S. Bovino, R. A. A. Bowler, G. Calistro Rivera, E. da Cunha, R. L. Davies, M. Killi, I. De Looze, A. Ferrara, D. B. Fisher, R. Herrera-Camus, R. Ikeda, T. Lambert, J. Li, D. Lutz, I. Mitsuhashi, M. Palla, M. Relaño, J. Spilker, T. Naab, K. Tadaki, K. Telikova, H. Übler, S. van der Giessen, V. Villanueva
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Science Foundation, National Radio Astronomy Observatory, Australian Government, Fonds Wetenschappelijk Onderzoek, Korea Astronomy and Space Science Institute, Max-Planck-Gesellschaft, Isaac Newton Trust, National Astronomical Observatory of Japan, Vlaamse regering, Hellenic Foundation for Research and Innovation, ARC Centre of Excellence for All-Sky Astrophysics, Agencia Nacional de Investigación y Desarrollo, Horizon 2020 Framework Programme, Science and Technology Facilities Council, Australian Research Council, Japan Society for the Promotion of Science, National Institutes of Natural Sciences, Agencia Estatal de Investigación, H2020 European Research Council
Awards: Galaxy evolution in high definition with the world's largest telescopes, G1175115578, UNVEILING THE NATURE OF THE FIRST GALAXIES AT THE END OF COSMIC REIONIZATION, G2262748287, G2469010403, The origin of cosmic dust in galaxies, G300979063, G3189640633, G3333666985, G34346518, G3452655474, G3480869486, G3843619696, Calibration of the spatially resolved SFR-[CII] relation in the Early Universe, G4072214037, G425668148, G426156348, G4534730369, G457452161, G4974873094, ALMA望遠鏡による遠方銀河の構造とその起源の解明, G5080475149, G5180915604, G5834573078, 巨大望遠鏡群によって解き明かす加速成長期にある銀河の内部構造, Galactic Outflows: Pushing the Distance Frontiers, Growing galaxies: a consistent view of star formation across cosmic time, A Complete Understanding of Massive Galaxy Formation into the Epoch of Reionization, G683931746, 口腔粘膜の代謝について, G7084143925, G751615522, 古代説話における諸寺縁起の研究, G7699577782, G7849195723, G7915199406, The resolved lifecycle of metals and dust in nearby galaxies, G8280170401, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA), G966226324
OpenAlex ID: W4392575403