2015ApJ...799...11X

We present ALMA Cycle-0 observations of the CO (6-5) line emission and of the 435 µm dust continuum emission in the central kiloparsec of NGC 1614, a local luminous infrared galaxy at a distance of 67.8 Mpc (1" = 329pc). The CO emission is well resolved by the ALMA beam (0.''26x0.''20) into a circumnuclear ring, with an integrated flux of f_CO(6–5)= 898 (± 153) Jy km/s, which is 63(± 12)% of the total CO (6-5) flux measured by Herschel. The molecular ring, located between 100pc < r < 350pc from the nucleus, looks clumpy and includes seven unresolved (or marginally resolved) knots with median velocity dispersion of ∼40 km/s. These knots are associated with strong star formation regions with Σ_SFR∼ 100 M_☉/yr/kpc2 and Σ_Gas ∼ 10⁴M_☉/pc2. The non-detections of the nucleus in both the CO (6-5) line emission and the 435 µm continuum rule out, with relatively high confidence, a Compton-thick active galactic nucleus in NGC 1614. Comparisons with radio continuum emission show a strong deviation from an expected local correlation between Σ_Gas and Σ_SFR, indicating a breakdown of the Kennicutt-Schmidt law on the linear scale of ∼100 pc.