Synthetic Observations of Simulated Radio Galaxies I: Radio and X-ray Analysis

We present an extensive synthetic observational analysis of numericallysimulated radio galaxies designed to explore the effectiveness of conventional observational analyses at recovering physical source properties. These are the first numerical simulations with sufficient physical detail to allow such a study. The present paper focuses on extraction of magnetic field properties from nonthermal intensity information. Synchrotron and inverse-Compton intensities were effective in providing meaningful information about distributions and strengths of magnetic fields, although considerable care was called for in quantitative usage of the information. Correlations between radio and X-ray surface brightness correctly revealed useful dynamical relationships between particles and fields, for example. Magnetic field strength estimates derived from the ratio of X-ray to radio intensity were mostly within about a factor of two of the RMS field strength along a given line of sight. When emissions along a given line of sight were dominated by regions close to the minimum energy/equipartition condition, the field strengths derived from the standard power-law-spectrum minimum energy calculation were also reasonably close to actual field strengths, except when spectral aging was evident. Otherwise, biases in the minimum-energy magnetic field estimation mirrored actual differences from equipartition. The ratio of the inverse-Compton-estimated magnetic field to the minimum-energy magnetic field provided a rough measure of the actual total energy in particles and fields in most instances, although this measure was accurate within only about an order Applied Physics Division, MS B259, Los Alamos National Laboratory, Los Alamos, NM, 87545; [email protected] School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455; [email protected] Department of Astronomy & Space Science, Chungnam National University, Daejeon, 305-764 Korea; [email protected]