21 cm Synthesis Observations of VIRGOHI 21—A Possible Dark Galaxy in the Virgo Cluster

  title={21 cm Synthesis Observations of VIRGOHI 21—A Possible Dark Galaxy in the Virgo Cluster},
  author={Robert. F. Minchin and Jonathan Ivor Davies and Michael John Disney and Marco Grossi and Sabina Sabatini and Peter J. Boyce and Diego Garcia and Christopher D. Impey and Christine A. Jordan and Robert Lang and Andrew Robert Marble and Sarah Roberts and Wim van Driel Arecibo Observatory and Cardiff University and Osservatorio Astrofisico di Arcetri and Osservatorio Astronomico di Roma and University of Bonn and Steward Observatory and Jodrell Bank Observatory and Observatoire de Paris},
  journal={The Astrophysical Journal},
  pages={1056 - 1064}
Many observations indicate that dark matter dominates the extragalactic universe, yet no totally dark structure of galactic proportions has ever been convincingly identified. Previously, we have suggested that VIRGOHI 21, a 21 cm source we found in the Virgo Cluster using Jodrell Bank, was a possible dark galaxy because of its broad line width (~200 km s-1) unaccompanied by any visible gravitational source to account for it. We have now imaged VIRGOHI 21 in the neutral hydrogen line and find… 

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