Faint and fading tails : the fate of stripped HI gas in Virgo cluster
  galaxies
  Although many galaxies in the Virgo cluster are known to have lost
significant amounts of HI gas, only about a dozen features are known where the
HI extends significantly outside its parent galaxy. Previous numerical
simulations have predicted that HI removed by ram pressure stripping should
have column densities far in excess of the sensitivity limits of observational
surveys. We construct a simple model to try and quantify how many streams we
might expect to detect. This accounts for the expected random orientation of
the streams in position and velocity space as well as the expected stream
length and mass of stripped HI. Using archival data from the Arecibo Galaxy
Environment Survey, we search for any streams which might previously have been
missed in earlier analyses. We report the confident detection of ten streams as
well as sixteen other less sure detections. We show that these well-match our
analytic predictions for which galaxies should be actively losing gas, however
the mass of the streams is typically far below the amount of missing HI in
their parent galaxies, implying that a phase change and/or dispersal renders
the gas undetectable. By estimating the orbital timescales we estimate that
dissolution rates of 1-10 Msolar/yr are able to explain both the presence of a
few long, massive streams and the greater number of shorter, less massive
features.
