Spectrum of the ¹³CO 1−0 emission in NGC 1614 (channel width: 10 km s^-1, left), and overlay of the integrated emission contours on top of an HST ACS F435W filter gray-scale image (right). The contours in the map obtained from natural weighting start at 4σ and are spaced in steps of 3σ. The 1σ sensitivity here is ~1.4 mJy beam^-1. The beam (see Table 1) is depicted in the bottom right corner. The cross marks the phase center. North is up, east to the left.