We report the discovery of a large H I cloud in the central regions of the Virgo cluster. It is 110× 25 kpc in size and contains 3.4× 108 M⊙ of H I. The morphology and kinematics of this cloud strongly suggest that it consists of H I removed from the galaxy NGC 4388 by ram-pressure stripping. It is more likely the result of an interaction of the ISM of NGC 4388 with the hot halo of the M 86 group and not with the ICM centred on M 87. The large extent of the plume suggests that gas stripped from cluster galaxies can remain neutral for at least 108 yr. Locally, the column density is well above 1020 cm-2, suggesting that the intra-cluster H II regions known to exist in Virgo may have formed from gas stripped from cluster galaxies. The existence of the H I plume suggests that stripping of infalling spirals contributes to the enrichment of the ICM. The H I object in the Virgo cluster recently reported by Minchin et al. (2005, ApJ, 622, L21) may have a similar origin and may therefore not be a "dark galaxy".
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机译：我们报告在处女座星团的中心区域发现了一个巨大的H I云。它的大小为110×25 kpc，包含3.4×108M⊙的HI。这朵云的形态学和运动学特征强烈表明，它由通过冲压冲撞从星系NGC 4388中去除的H I组成。 NGC 4388的ISM与M 86群的热晕相互作用，而不是与以M 87为中心的ICM相互作用，更可能是这种相互作用的结果。大范围的羽流表明，从星系星系中剥离出来的气体可以保持中性至少108年。在本地，列密度远高于1020 cm-2，这表明处女座中已知的群集内H II区可能是由从星系星系中剥离出来的气体形成的。 H I羽流的存在表明，下降螺旋的剥离有助于ICM的富集。 Minchin等人最近报道的处女座星团中的H I对象。 （2005，ApJ，622，L21）可能具有相似的起源，因此可能不是“暗星系”。
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