E016 · formal geometry overlay
M31 XMM FoV × formal annuli × Ring_v7
These figures overlay the nominal 15′ XMM FoVs of the E015-verified pointings with the seven fine rings in the current formal variable-W1 annulus registry: outer boundaries a=40, 48, 56, 64, 80, 96, 112′. Yellow dashed curves additionally show, and label along the major axis, the inner variable-W1 geometric boundaries a=8, 16, 24, 32′, for geometric checks of inner-region spectral extraction. Ring_v7 is shown using the formal composite definition R1 ∪ Radd1; the historical small ring Radd2 is not included.
a≤40′ geometry are solid; the other nearby FoVs are dashed. This overlay is not MOS CCD, GTI, source-mask, vignetting, effective-sky-area, or exposure coverage, and it does not claim that spectral extraction is complete in any outer annulus.WISE W1 (3.4 μm)
Left: all a=32–112′ formal annuli and the E015 15′ FoVs. Right: zoom of the Ring_v7 inner region; cyan hatch comes from the pixel-validated source mask R1 | Radd1, not a contour fill. The red dashed curves are DS9 subtraction primitives; construction was fail-closed validated such that E2, C8, G1/NGC 205, and G2/M32 are not inside the hatch. Click to enlarge.
WISE W4 (22 μm)
Uses the same M31 centre, 270′×270′ sky-coordinate extent, and overlay as W1. W4 (22 μm) uses an independent display stretch for visual inspection of its clear star-forming-ring morphology; it remains only a registered display backdrop and neither changes the Ring_v7 definition nor selects spectral extraction.
| outer boundary | stable region ID | annulus | role |
|---|---|---|---|
| a=40′ | a032_040 | 32–40′ | formal fine annulus |
| a=48′ | a040_048 | 40–48′ | formal fine annulus |
| a=56′ | a048_056 | 48–56′ | formal fine annulus |
| a=64′ | a056_064 | 56–64′ | formal fine annulus |
| a=80′ | a064_080 | 64–80′ | formal fine annulus |
| a=96′ | a080_096 | 80–96′ | formal fine annulus |
| a=112′ | a096_112 | 96–112′ | formal fine annulus |
Provenance: E015 local coordinate inventory; formal variable-W1 region registry; Ring_v7 composite-region declaration and branch SHA-256 validation. This page is for geometry planning / visual QA and contains no spectral extraction, model, or physical interpretation.