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.

Abstract

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.

Citation

Geach, J. E., Ivison, R. J., Dye, S., & Oteo, I. (2018). A magnified view of circumnuclear star formation and feedback around an active galactic nucleus at z = 2.6. Astrophysical Journal Letters, 866(1), 1-7. https://doi.org/10.3847/2041-8213/aae375

• 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
• DOI: https://doi.org/10.3847/2041-8213/aae375
• Keywords: galaxies: active – galaxies: evolution – galaxies: individual (9io9) – galaxies: nuclei – radio continuum: galaxies – submillimeter: galaxies
• Public URL: https://nottingham-repository.worktribe.com/output/1241290
• Publisher URL: http://iopscience.iop.org/article/10.3847/2041-8213/aae375