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 (CO)-C-12 ( J = 1-0) line emission from the radio lobe edge-on spiral galaxy NGC 3079 u sing a seven-element millimeter-wave interferometer at the Nobeyama Radio O bservatory, which consisted of the 45 m telescope and six-element array. Th e nuclear molecular disk (NMD) of 750 pc radius is found to be inclined by 20 degrees from the optical disk, and the NMD has spiral arms. An ultra-hig h-density core (UHC) of molecular gas was found at the nucleus. The gaseous mass of the UHC within 125 pc radius is as large as similar to3 x 10(8) M. , an order of magnitude more massive than that in the same area of the Gala ctic center, and the mean density is as high as similar to3 x 10(3)H(2) cm- (3). A position-velocity diagram along the major axis indicates that the ro tation curve already starts at a finite velocity exceeding 300 km s(-1) fro m the nucleus. The surface mass density in the central region is estimated to be as high as similar to 10(5) M. pc(-2), producing a very deep gravitat ional potential. We argue that the very large differential rotation in such a deep potential will keep the UHC gravitationally stable during the curre nt star formation.