2017ApJ...838..146L

We use the Atacama Large Millimeter Array (ALMA) to detect and image CO (1-0) emission from Minkowski's Object, a dwarf galaxy in the cluster Abell 194 that is interacting with a radio jet from a nearby elliptical galaxy. The ALMA observations, which are the first to detect molecular gas in Minkowski's Object, also image the high-frequency continuum emission from the radio jet, allowing us to study the interaction in detail. We estimate the range in the mass of molecular gas in Minkowski's Object assuming two different values of the ratio of the molecular gas mass to the CO luminosity, α_CO. For the Milky Way value of α_CO=4.6 M_☉(Kkms^–1pc²)^–1 we obtain a molecular gas mass of M_H2_=3.0×10⁷ M_☉, 6% of the H I gas mass. We also use the prescription of Narayanan et al. (2012) to estimate an α_CO=27 M_☉(Kkms^–1pc²)^–1, in which case we obtain M_H2_=1.8×10⁸ M_☉, 36% of the H I mass. The observations are consistent with previous claims of star formation being induced in Minkowski's Object via the passage of the radio jet, and it therefore being a rare local example of positive feedback from an active galactic nucleus. In particular, we find highly efficient star formation, with gas depletion timescales ∼5×10⁷–3×10⁸ year (for assumed values of α_CO=4.6 and 27 M_☉(Kkms^–1pc²)^–1, respectively) in the upstream regions of Minkowski's Object that were struck first by the jet, and less efficient star formation downstream. We discuss the implications of this observation for models of jet-induced star formation and radio-mode feedback in massive galaxies.