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We have used the SINFONI near-infrared integral field unit on the Very Large Telescope to resolve the optical emission line structure of one of the brightest (LLyα ≈ 1044 erg s-1) and nearest (z ≈ 2.38) of all Lyα blobs (LABs). The target, known in the literature as object "B1", lies at a redshift where the main optical emission lines are accessible in the observed near-infrared.We detect luminous [O III] λλ4959,5007 and Hα emission with a spatial extent of at least 32 × 40 kpc (4" × 5"). The dominant optical emission line component shows relatively broad lines (600-800 km s-1, FWHM) and line ratios consistent with active galactic nucleus (AGN) photoionization. The new evidence for AGN photoionization, combined with previously detected C IV and luminous, warm infrared emission, suggest that B1 is the site of a hidden quasar. This is confirmed by the fact that [O II] is relatively weak compared with [O III] (extinction-corrected [O III]/[O II] of about 3.8), which is indicative of a high, Seyfert-like ionization parameter. From the extinction-corrected [O III] luminosity we infer a bolometric AGN luminosity of ~3×1046 erg s-1, and further conclude that the obscured AGN may be Compton-thick given existing X-ray limits. The large line widths observed are consistent with clouds moving within the narrow-line region of a luminous QSO. The AGN scenario is capable of producing sufficient ionizing photons to power the Lyα, even in the presence of dust. By performing a census of similar objects in the literature, we find that virtually all luminous LABs harbor obscured quasars. Based on simple duty-cycle arguments, we conclude that AGNs are the main drivers of the Lyα in LABs rather than the gravitational heating and subsequent cooling suggested by cold stream models. We also conclude that the empirical relation between LABs and overdense environments at high redshift must be due to a more fundamental correlation between AGNs (or massive galaxies) and environment. [ABSTRACT FROM AUTHOR]

We report ALMA Early Science CO(1-0) and CO(3-2) observations of the brightest cluster galaxy (BCG) in A1664. The BCG contains 1.1 × 1010M☼ of molecular gas divided roughly equally between two distinct velocity systems: one from –250 to +250 km s–1 centered on the BCG's systemic velocity and a high-velocity system blueshifted by 570 km s–1 with respect to the systemic velocity. The BCG's systemic component shows a smooth velocity gradient across the BCG center, suggestive of rotation about the nucleus. However, the mass and velocity structure are highly asymmetric and there is little star formation coincident with a putative disk. It may be an inflow of gas that will settle into a disk over several 108 yr. The high-velocity system consists of two gas clumps, each ∼2 kpc across, located to the north and southeast of the nucleus. Each has a line of sight velocity spread of 250-300 km s–1. The velocity of the gas in the high-velocity system increases toward the BCG center and may be a massive flow into the nucleus. However, the velocity gradient is not smooth. These structures are also coincident with low optical-ultraviolet surface brightness regions, which could indicate dust extinction associated with each clump. The structure is complex, making a clear interpretation difficult, but if the dusty, molecular gas lies predominantly in front of the BCG, the blueshifted velocities would indicate an outflow. Based on the energy requirements, such a massive outflow would most likely be driven by the active galactic nucleus. A merger origin is unlikely but cannot be ruled out. [ABSTRACT FROM AUTHOR]