High-Velocity Molecular Gas in the Galactic Center Radio Lobe

We point out a possible association of high-velocity molecular gas with the Galactic Center Radio Lobe (GCL). A molecular spur in the eastern GCL ridge is receding at \Vlsr \sim +100 \kms, and the western spur approaching at \Vlsr \sim -150 \kms, suggesting a high-velocity rotation of the GCL. We study the kinematics of the GCL based on these molecular line data.Comment: To appear in ApJ. Letters, Plain TeX, Figures on reques

Dark Bulge, Exponential Disk, and Massive Halo in the Large Magellanic Cloud

The rotation curve of the Large Magellanic Cloud, which we have derived from high-resolution HI position-velocity diagrams observed by Kim et al (1998), shows a steep central rise and flat rotation with a gradual rise toward the edge. Using the rotation curve, we have calculated the distribution of surface mass density, and show that the LMC has a dark compact bulge, an exponential disk, and a massive halo. The bulge is 1.2 kpc away from the center of the stellar bar, and is not associated with an optical counterpart. This indicates that the "dark bulge" has a large fraction of dark matter, with an anomalously high mass-to-luminosity (M/L) ratio. On the contrary, the stellar bar has a smaller M/L ratio compared to the surrounding regions. (http://www.ioa.s.u-tokyo.ac.jp/~sofue/99lmc.htm)Comment: PASJ 1999 in press, Latex with Postscript figure

Galactic Center Molecular Arms, Ring and Expanding Shells. II - Expanding Molecular Shell -

We investigate the three-dimensional structure of the so-called ``200-pc expanding molecular ring" in the Galactic Center by analyzing (b, Vlsr) diagrams of the 13CO(J=1-0) line emission from the Bell-Telephone Laboratory survey. We show that the b-v features can be fitted by a spheroidal shell pinched at the equator (dumbbell-shaped shell), which we call the expanding molecular shell (EMS). The radius is about 180 pc and the vertical extent is more than +/-50 pc. The shell is expanding at 160 km/s, and is rotating at 70 km/s. The association of the radio continuum emission indicates that the EMS is a mixture of molecular and ionized hydrogen gases. An extended hot (X-ray) plasma appears to fill the interior of the shell. The estimated molecular mass of the shell is approximately 1.E7 Msun and its kinetic energy 2.E54 ergs.Comment: To appear in PASJ vol.47, No.5, 1995, Plain TeX, Figures on reques