Ultra–High-Density Molecular Core and Warped Nuclear Disk in the Deep Potential of Radio Lobe Galaxy NGC 3079

We have performed high-resolution synthesis observations of the 12CO (J=1-0)line emission from the radio lobe edge-on spiral NGC 3079 using a 7-elementmm-wave interferometer at Nobeyama, which consisted of the 45-m telescope and6-element Array. The molecular nuclear disk (NMD) of 750 pc radius is found tobe inclined by 20 degrees from the optical disk, and the NMD has spiral arms.An ultra-high-density molecular core (UHC) was found at the nucleus. Thegaseous mass of the UHC within 125 pc radius is as large as about 3 x 10^8Msun, an order of magnitude more massive than that in the same area of theGalactic Center, and the mean density is as high as approximately 3 x 10^3 H2cm^-3. A position-velocity diagram along the major axis indicates that therotation curve starts at a finite velocity exceeding 300 \kms already from thenucleus. The surface mass density in the central region is estimated to be ashigh as about 10^5 Msun pc^-2, producing a very deep gravitational potential.We argue that the very large differential rotation in such a deep potentialwill keep the UHC gravitationally stable from current star formation.