Construction of Hybrid Model for Astrophysical Jets

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FY2003We constructed a steady jet model emanating from a geometrically thin disk, taking into account the gas, radiation, and magnetic pressures. We have found that the jet flow generally have multiple critical (transonic) points, since the gravitational and radiative forces along the streamline do not monotonic.As a result, the jet flow is accelerated by passing through the saddle type critical point to be supersonic.We also obtained an approximate empirical formula for the terminal speed of jet flows.FY2004We examined on-axis jets of supercritical accretion disks, where the mass-accretion rate highly exceeds the Eddington accretion rate. The jet gas suffers from the gravity of the central object, the radiative flux from the disk, and the radiation drag force of the intense radiation fields of the disk.We have calculated the equilibrium speed as well as the terminal one for on-axis jets.We also found a useful expression between the terminal speed and the disk luminosity.FY2005We carefully examined the relativistic radiative flow from a luminous disk under a fully special relativistic treatment. The flow is assumed to be vertical, and the gravity, the gas pressure, and the viscous heating are ignored. The radiatively-driven flow in a luminous disk is numerically solved, from the flow base (disk "inside") to the flow top. For a given optical depth and appropriate initial conditions at the flow base, where the flow starts, a loaded mass in the flow is obtained as an eigenvalue of the boundary condition at the flow top. Moreover, the flow velocity and radiation fields along the flow are obtained as a function of the optical depth.