Formation of a massive black hole at the center of the superbubble in M82

We performed (CO)-C-12 (1-0), (CO)-C-13 (1-0), and HCN (1-0) interferometri c observations of the central region (about 450 pc in radius) of M82 with t he Nobeyama Millimeter Array and have successfully imaged a molecular super bubble and spurs. The center of the superbubble is clearly shifted from the nucleus by 140 pc. This position is close to that of the massive black hol e (BH) of greater than or similar to 460 M. and the 2.2 mum secondary peak (a luminous, supergiant-dominated cluster), which strongly suggests that th ese objects may be related to the formation of the superbubble. Considerati on of star formation in the cluster based on the infrared data indicates th at (1) the energy release from supernovae can account for the kinetic energ y of the superbubble, (2) the total mass of stellar-mass BHs available for building up the massive BH may be much higher than 460 M., and (3) it is po ssible to form, the middle-mass BH of 10(2)-10(3) M. within the timescale o f the superbubble. We suggest that the massive BH was produced and is growi ng in the intense starburst region.