Ring v6 morphology 与 variable-W1 a=44–48′
这是未来 ring-dominated extraction 的纯几何候选图，不是新的抽谱、ObsID FoV 选择、CCD 有效面积图或拟合结果。
优化目标：
area(candidate ∩ Ring) / area(candidate − Ring)。候选必须是既有 nested variable-W1 a(r), q(r), PA(r) 边界族中的连续 annulus。
| quantity | value |
|---|---|
| inner boundary | a=44′, q=0.277, PA=39.9° E of N |
| outer boundary | a=48′, q=0.280, PA=37.7° E of N |
| Ring ∩ candidate | 287.12 arcmin² |
| candidate − Ring | 54.84 arcmin² |
| overlap / non-Ring | 5.236 |
| Ring purity within candidate | 83.96% |
| fraction of all Ring mask captured | 22.15% |
Green contours: trusted Ring-v6 morphology mask. Magenta boundaries: a=44–48′ candidate. The background is the trusted XMM-domain binary Ring-v6 mask. The numerical comparison is evaluated on the XMM-domain Ring-v6 pixel mask; neither panel applies exposure, FoV, bad-CCD, point-source, or sky-area weighting.