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A magnified view of circumnuclear star formation and feedback around an active galactic nucleus at z = 2.6

Geach, J. E.; Ivison, R. J.; Dye, S.; Oteo, I.

A magnified view of circumnuclear star formation and feedback around an active galactic nucleus at z = 2.6 Thumbnail


J. E. Geach

R. J. Ivison

Associate Professor

I. Oteo


We present Atacama Large Millimeter/submillimeter Array observations of an intrinsically radio-bright (L 1.4 GHz = (1.7 ± 0.1) × 1025 W Hz−1) and infrared luminous (L IR ≈ 1013 L ⊙) galaxy at z = 2.6. The infrared-to-radio luminosity ratio, q = 1.8, indicates the presence of a radio-loud active galactic nucleus (AGN). Gravitational lensing by two foreground galaxies at z ≈ 0.2 provides access to physical scales of approximately 360 pc, and we resolve a 2.5 kpc radius ring of star-forming molecular gas, traced by atomic carbon C i (1 → 0) and carbon monoxide CO (J = 4 → 3). We also detect emission from the cyanide radical, CN (N = 4 → 3). With a velocity width of 680 km s−1, this traces dense molecular gas traveling at velocities nearly a factor of two larger than the rotation speed of the molecular ring. While this could indicate the presence of a dynamical and photochemical interaction between the AGN and molecular interstellar medium on scales of a few 100 pc, ongoing feedback is unlikely to have a significant impact on the assembly of stellar mass in the molecular ring, given the ~10 s Myr depletion timescale due to star formation.

Journal Article Type Article
Acceptance Date Oct 10, 2018
Online Publication Date Oct 10, 2018
Publication Date Sep 20, 2018
Deposit Date Nov 9, 2018
Publicly Available Date Nov 9, 2018
Journal The Astrophysical Journal
Print ISSN 2041-8213
Electronic ISSN 2041-8213
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 866
Issue 1
Pages 1-7
Keywords galaxies: active – galaxies: evolution – galaxies: individual (9io9) – galaxies: nuclei – radio continuum: galaxies – submillimeter: galaxies
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A Magnified View of Circumnuclear Star Formation and Feedback around an Active Galactic Nucleus at z = 2.6 (1.7 Mb)

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