2008A&A...482...43G

We report the results of an HI blind survey of 80deg² of the Virgo cluster, based on the 08°≤δ≤16° strip of ALFALFA, the Arecibo Legacy Fast ALFA Survey. 187 HI sources of high significance are found providing a complete census of HI sources in this region of the Virgo cluster (-1000<cz<3000km/s) with M_HI≥10^7.5∼8_☉. 156/187 (83%) sources are identified with optical galaxies from the Virgo Cluster Catalogue (Binggeli et al., 1985AJ.....90.1681B), all but 8 with late-type galaxies. Ten sources are not associated with optical galaxies and were found to correspond to tidally-disrupted systems (see Kent et al., 2007ApJ...665L..15K; and Haynes et al., 2007ApJ...665L..19H). The remaining 21 (11%) are associated with galaxies that are not listed in the Virgo Cluster Catalogue. For all sources with an optical counterpart in the Sloan Digital Sky Survey, we analyzed i-band SDSS plates to measure optical structural parameters. We find that in the Virgo cluster: i) HI inhabits galaxies that are structurally similar to ordinary late-type galaxies; ii) their HI content can be predicted from their optical luminosity; iii) low surface brightness galaxies have low optical luminosity and contain small quantities of neutral hydrogen; iv) low surface brightness, massive Malin1 type galaxies are comfortably rare objects (less than 0.5%); v) there are no ``dark-galaxies'' with HI masses M_HI≥10^7.5∼8M_☉; vi) less than 1% of early-type galaxies contain neutral hydrogen with M_HI≥10^7.5∼8M_☉ (di Serego Alighieri et al., 2007A&A...474..851D).