Abstract

The distribution of H I in the normal, barred lenticular galaxy NGC 4262 in the Virgo Cluster has been mapped at a resolution of 13arcsec×51arcsec. The gas is confined to a narrow ring, apparently in circular rotation about the galaxy center. The ring has a diameter about twice the optical diameter of the galaxy, and is inclined by at least 50° (and possibly as much as 120°) to the optical disk. The rotation velocity of the ring implies that atomic hydrogen accounts for far less than 1% of the total mass, and that the total mass-to-light ratio is near 20. The local mass-to-light ratio in the ring is at least 50 to 80, giving evidence for a massive, "invisible" envelope or halo surrounding the galaxy. The authors consider two reasonable explanations for the presence of gas in NGC 4262, namely that it is the remnant of the primordial proto-galaxy cloud, or of a captured, gas-rich dwarf or intergalactic H I cloud.