🔭 DRAFT RESEARCH PROPOSAL · INFRARED SPECTROSCOPY · JWST NIRSpec / IFU
A deep spectroscopic mapping program to distinguish natural gas-starvation from artificially managed interstellar medium depletion within 0.5 parsecs of OC's central mass — using chemical tracers of tidal brown-dwarf disruption as the primary discriminant · Working draft · April 2026
Mahida et al. (2025) found zero radio emission from OC's core at ATCA sensitivity (accretion rate < 10⁻¹⁰ Ṁ_Edd). Chen et al. (2025) found no NIRCam/MIRI accretion signature in JWST data. Both studies are consistent with a completely gas-starved, dynamically relaxed environment — which is also what a 12 Gyr stripped dwarf nucleus without ongoing star formation should look like.
The OCS roadmap suggests that a Phase 4 civilisation would deliberately clear its accretion environment and feed the IMBH through controlled tidal disruption events — specifically, disrupting low-mass objects (brown dwarfs, M-dwarfs) at precisely managed rates. This "managed feeding" scenario is thermodynamically identical to a natural quiescent state at the electromagnetic level, but it would leave chemical fingerprints inconsistent with a truly gas-starved environment.
The tidal disruption of a brown dwarf (BD) or low-mass M-dwarf near a massive black hole produces characteristic chemical signatures unlike those from normal stellar evolution:
JWST's NIRSpec Integral Field Unit provides simultaneous spatial and spectral coverage over 3″ × 3″ at R ≈ 100 (PRISM) or R ≈ 1,000–2,700 (medium-resolution gratings). At OC's distance of 5.49 kpc, 3″ corresponds to ~0.08 pc. Spatial scope restated 2026-09-25 (P0-15.5): a single pointing covers the innermost ~0.08 pc containing the fast-moving Häberle stars, and the 5×5 mosaic extends coverage to ≈0.5 pc as a filled square aperture, not a radial profile along a preferred axis. Radial comparisons at 0.2–0.5 pc are mosaic-by-annulus comparisons across that square footprint, with fewer independent samples at large radii than an earlier version of this text implied.
Chen et al. (2025) have already observed OC with NIRCam and MIRI. JWST's multi-cycle GO programs have generated significant OC archival data. Phase 1 requires no new observing time — it is a systematic reanalysis of all existing JWST data for OC:
| Parameter | Value |
|---|---|
| Mode | NIRSpec IFU, PRISM/CLEAR (R ≈ 100, 0.6–5.3 µm) as the workhorse: covers Li I λ1.048 µm, Fe I λ1.189 µm, the Ca II triplet λλ0.85 µm, Hα λ0.656 µm and Paα λ1.875 µm simultaneously. G140M/F070LP (R ≈ 1,000, 0.90–1.27 µm) added for Li I/Fe I depletion ratios on the brightest giants [config corrected 2026-09-25, P0-15.5: the previous G140M/F100LP pairing is invalid, because G140M pairs with F070LP and its 0.90–1.27 µm range excludes the Ca II triplet and Hα, which only the PRISM covers] |
| Field of view | 3″ × 3″ per IFU pointing; mosaic of 5×5 pointings to cover inner 0.5 pc (15″ diameter) |
| Proposed exposure | 5h per pointing × 25 pointings = ~125h total JWST time |
| Line targets | Li I λ1.048 µm, Fe I λ1.189 µm, Ca II triplet λλ0.85 µm, Hα λ0.656 µm (diffuse gas), Paα λ1.875 µm (ionised gas) — all inside the PRISM range; Li I/Fe I also inside G140M/F070LP |
| Resolution cost (stated) | The PRISM's R ≈ 100 degrades abundance/depletion precision relative to a medium-resolution grating; accepted to keep the full optical+near-IR line set in one setup |
| Continuum targets | Broadband SED of diffuse ISM; compare F150W/F277W/F444W flux ratio against model |
A synoptic monitoring program (3–4 NIRCam epochs per year) would detect short-duration IR transients consistent with tidal disruption events or accretion flares. Cross-reference any detected transients with KM3NeT/IceCube neutrino burst alerts — a tidal disruption event accompanied by a high-energy neutrino excess would be extraordinary evidence.
| Observable | Natural null result | Consistent with OCS | Inconsistent with OCS |
|---|---|---|---|
| Li I abundance in inner 0.1 pc | Consistent with evolved stellar population (depleted) | Anomalous excess above 12 Gyr model | Consistent with null (no enrichment) |
| Gas-to-dust ratio vs radius | Smooth gradient matching stellar wind models | Localized deficit in innermost 0.1 pc relative to 0.2–0.5 pc | Gradient consistent with natural depletion |
| Heavy-element dust abundance in core | Consistent with cluster metallicity | Anomalously low refractory dust in inner 0.1 pc | Normal abundance gradient |
| IR transient rate | <1 event/yr above JWST detection threshold | Quasi-periodic transients with rates consistent with OCS feeding model | Zero transients or rates inconsistent with any periodic pattern |
| Phase | Timeline | Milestone | Deliverable |
|---|---|---|---|
| 1 (archival) | Year 1, Q1–Q3 | Download and reprocess all existing JWST OC data; stellar abundance extraction | Archival chemical abundance map |
| 1 (archival) | Year 1, Q4 | Comparison against 12 Gyr stellar evolution models; flag anomalies | Anomaly report; JWST GO proposal preparation |
| 2 (new obs) | Year 2 | JWST Cycle 4/5 GO proposal submission; if approved, IFU spectroscopic mosaic | NIRSpec IFU spectral data cube |
| 2 | Year 2–3 | Abundance mapping; gas-to-dust ratio spatial analysis; Li I search | Chemical abundance map paper |
| 3 (monitoring) | Year 3–4 | NIRCam synoptic monitoring; transient cross-correlation with KM3NeT alerts | Transient rate paper; multi-messenger alert integration |
| Item | Cost (USD) | Notes |
|---|---|---|
| Postdoc (3 years) | 180,000 | JWST data analysis, stellar spectroscopy expertise required |
| HPC compute | 15,000 | Spectral extraction, stellar population modelling, IFU data cubes |
| JWST observing time | 0 (Phase 1) / ~50,000 (Phase 2 est.) | Phase 1 uses existing archival data; Phase 2 requires GO proposal |
| Travel + publication | 12,000 | STScI meetings, JWST user conference, two open-access papers |
| Total (Phase 1 + 2) | ~257,000 | Phase 1 alone: ~$207,000 |