Testing Knot Magnetic Fields with the Inverse-Compton to Synchrotron Ratio in Large-Scale Jets

This paper addresses a single accounting question in the physics of relativistic jets: whether the X-ray emission of large-scale jet knots can be inverse-Compton scattering of the cosmic microwave background by the radio-emitting electrons, or whether the flux ratio forbids it at equipartition fields. Using published radio-to-X-ray flux ratios, equipartition fields and plausible Doppler factors for five knots, the calculation derives new bounds and budgets from standard synchrotron and special-relativistic relations, with every number produced by the deposited compute script. The headline results are: . 3C 273 knot A1: 219, PKS 0637-752 knot: 63.2, M87 knot A: 212, Centaurus A knot: 110, 3C 120 knot: 112. The knots divide. The study is a computation from stated assumptions and published inputs; it is simulated, not measured, and its conclusions are stated at the precision those inputs support.