Enormous Lyα nebulae Slug and Jackpot, as seen in Lyα emission (color scale; see Cantalupo et al. 2014; Hennawi et al. 2015), in CO(3−2) (red contours), and 3 mm continuum (green contours). The large dashed circles show the primary beams of our 3 mm observations, while the blue ellipses at the bottom left corner show the synthesized beams. The solid and dotted contours show the positive and negative 2, 3, 4, 5, ...15-σ isophotes, where 1-σ = 122 and 100 μJy beam⁻¹ for the CO(3−2) line maps of the Slug and Jackpot nebulae, respectively, and 1-σ = 28 and 38 μJy beam⁻¹ for the 3 mm continuum of the two systems. Line maps were integrated over 300 km s⁻¹ (see Fig. 2). For Slug, the inset shows the CO map of the galaxy on the eastern side. The synchrotron continuum of the two radio-loud AGN in the two nebulae were also secured at high significance. Conversely, the UV-luminous quasar at the center of Slug and a star-forming galaxy at the northern edge of the Jackpot nebula are the only unambiguous CO detections in our data. No CO line nor 3 mm continuum detection is reported in either nebula.