## Accretion DisksRotating diskThe observation of the broad relativistic iron K Various numerical approaches have been suggested and used to calculate the profiles of emission lines: the historical method using the transfer function, direct integration of the trajectory of the photons, and elliptic integrals. We present new, fast and accurate methods that use integrated geodesic equations in terms of Jacobian elliptic functions, in both the Schwarzschild and the Kerr metrics, to produce accretion disc images and line profiles. Two different codes were designed in order to make maximal use of the symmetries of the Schwarzschild and Kerr solutions. In the Schwarzschild case, one can analytically map any point of the disc – even a warped one – into the image plane, which makes the calculations accurate and fast. In the Kerr case, the analytic form of the integrated geodesic equations is not as simple, so that some numerical interpolations are required in calculating line profiles, and the case of warped discs cannot be treated as easily. Both codes are able to calculate lines produced by material extending below the marginally stable orbit and can handle various emissivity and illumination laws. The computer codes for calculating line profiles are written in Delphi and run under Windows! Disks (ZIP 513 kB) |

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