2021RNAAS...5..217M

The Widefield Arecibo Virgo Extragalactic Survey (WAVES) was an ongoing H I survey of the Virgo Cluster with the Arecibo Observatory's 305 m William E. Gordon Telescope at the time of its structural failure. The full 20 square degrees of the southern field and 10 of the planned 35 square degrees of the northern field had been observed to full depth, adding to 25 square degrees observed to the same depth in the cluster by the Arecibo Galaxy Environment Survey. We here review what WAVES reveals about four optically dark H I structures that were previously discovered in the survey area, including two that are not seen despite being well above our detection limit.