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 using a seven-element millimeter-wave interferometer at the Nobeyama Radio Observatory, which consisted of the 45 m telescope and six-element array. The 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-high-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 Galactic 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 rotation curve already starts at a finite velocity exceeding 300 km s(-1) from 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 gravitational potential. We argue that the very large differential rotation in such a deep potential will keep the UHC gravitationally stable during the current star formation.