Persistent X-Ray Luminosity Against Spin-Down Power: The Rotation-Energy Deficit Across the Magnetar Catalogue

The defining anomaly of the anomalous X-ray pulsars was in their name: they radiated more in X-rays than their slowing rotation could pay for. The deficit is a clean, source-by-source number, the ratio of persistent luminosity to spin-down power, and recomputing it across the modern catalogue shows how common and how extreme the anomaly remains. Working from published values for the sources concerned, this paper computes the relevant quantities under one stated set of conventions and compares them source by source. Headline results: largest Lx over Edot source SGR 0418+5729; largest Lx over Edot 2.8e+03; sources Lx above Edot 11; sources rotation powered sufficient 7; n sources 18. The comparisons are budget statements: they establish whether the energies, stresses, powers and timescales involved are mutually consistent, and by what margin. Every number quoted is produced by the deposited compute.py script from the stated inputs, and the full per-source record is deposited as results.json alongside the text.