📻 DRAFT RESEARCH PROPOSAL · RADIO PULSAR TIMING · MEERKAT / SKA-MID

MeerKAT/SKA Millisecond Pulsar Timing Array: Gravitational Potential Mapping of Omega Centauri's Core

A high-cadence pulsar timing campaign to discriminate between a single IMBH and a dark cluster of stellar-mass black holes — providing a definitive gravitational test before LISA (~2035) while simultaneously searching for anomalous timing residuals consistent with the OCS computronium hypothesis · Working draft · April 2026

Why this proposal matters urgently: The Häberle et al. (2024) IMBH lower bounds and the Bañares-Hernández et al. (2025) upper limit are formally contradictory. LISA will not launch until ~2035. This proposal provides an independent gravitational discriminator using existing instruments over the next 3–5 years — directly addressing the foundational question of whether the OCS hypothesis has a physical substrate.

1. Scientific Rationale

1.1 The Core Falsification Gap

The OCS Macro Transcension Hypothesis requires a single massive IMBH as the energy and computational substrate. The current observational situation is ambiguous:

These constraints are methodologically inconsistent. A dedicated, high-cadence pulsar timing campaign directly measures the gravitational potential through line-of-sight accelerations, providing an independent probe with a distinct systematic error budget.

1.2 Why MSPs Are Ideal Gravitational Probes

Millisecond pulsars are the most stable natural clocks known, with period drift ~1 µs per 10¹⁵ years. Their line-of-sight accelerations (measured through secular changes in pulse period: Ṗ_obs = Ṗ_int + P · a_los / c) map the gravitational potential at their orbital radii with ~10⁻⁹ m/s² sensitivity per year of timing. OC hosts at least 18 confirmed MSPs — the densest known population in any globular cluster — spanning a range of projected radii from the core. Their radial acceleration profile directly encodes the mass distribution: a point-mass IMBH produces a smooth 1/r² profile, while a distributed dark mass produces an extended, flatter profile.

1.3 OCS Science Spinoff: Computronium Swarm Signature

If an IMBH is confirmed by the acceleration profile, the same timing dataset probes a secondary OCS prediction: a computronium swarm concentrated near the ISCO would contribute a localized mass excess that would produce anomalous, position-dependent timing residuals in MSPs whose line of sight passes close to the ISCO radius (~177,000 km for a 20,000 M☉ IMBH). This is speculative but falsifiable: the residuals would show a non-random angular pattern around the cluster center inconsistent with any astrophysical model.

2. Observation Strategy

2.1 MeerKAT (Immediate: 2025–2030)

ParameterValue
Target pulsarsAll 18+ confirmed OC MSPs; priority on those with smallest projected separation from core (<0.1 pc)
Observing cadenceBi-weekly (26 sessions/year) at L-band (1.28 GHz) and S-band (2.6 GHz); 2-hour sessions
Timing precision~1 µs ToA per session for brightest MSPs; ~10 µs for faint ones
Acceleration sensitivity~5 × 10⁻¹⁰ m/s² per year (brightest MSPs); ~2 × 10⁻⁹ m/s² (faint)
Primary science productsSecular period derivatives (Ṗ_obs) for all 18 MSPs; 3D acceleration field map of OC core
New pulsar searchCommensal deep imaging search with L-band data; expected 5–10 new MSPs (extrapolating Chen et al. 2024)

2.2 SKA-MID (Future: 2030+)

SKA-MID will increase timing precision by ~5× and enable detection of MSPs 10× fainter than MeerKAT's threshold. The legacy dataset from this proposal will serve as the timing baseline for SKA-era precision measurements. Specific SKA science goals include constraining the IMBH spin parameter a★ through frame-dragging effects on MSP orbits — a uniquely OCS-relevant measurement.

2.3 Falsification Framework

Acceleration profile resultInterpretationImplication for OCS
Smooth 1/r² profile consistent with point mass ≥8,200 M☉Single IMBH strongly supported; dark cluster disfavouredOCS physical substrate confirmed; proceed to Phase planning
Flat/extended profile matching 2–3 × 10⁵ M☉ distributed massDark cluster of ~10,000–20,000 stellar-mass BHs supportedOCS Phase 3-5 substrate falsified; no single BZ extraction point
Stochastic, unexplained residuals at small projected radiiLocalized mass perturbation inconsistent with smooth modelsComputronium swarm candidate (speculative; requires multi-messenger corroboration)
Null detection of secular Ṗ changesPulsar population too faint or too widely distributedInconclusive; await SKA

3. Synergy with Other Proposals

4. Work Plan

YearQuarterMilestoneDeliverable
1Q1–Q2MeerKAT time allocation; timing pipeline setup; ephemeris initialization for all 18 MSPsTiming pipeline documentation
1Q3–Q4First year bi-weekly observations; initial acceleration constraintsYear-1 timing baseline
2Q1–Q4Continued timing; new pulsar discovery analysis; 2-year acceleration profileAcceleration map v1; new MSP discoveries
3Q1–Q23-year profile; statistical comparison of point-mass vs extended-mass modelsIMBH vs dark cluster Bayesian comparison
3Q3–Q4Publication; SKA pathfinder coordinationSubmitted to MNRAS / ApJ
4ongoingContinued monitoring; SKA-MID baseline preparationSKA early science proposal

5. Budget

ItemCost (USD)Notes
Graduate RA (4 years)160,000Timing pipeline development, analysis, pulsar searches
MeerKAT observing time20,000~200 hours/year × 4 years at est. access costs
HPC compute12,000Bayesian timing analysis, TEMPO2/PINT, acceleration modelling
Travel + publication8,000MeerKAT/SARAO collaboration meetings, open-access fees
Total~200,000

6. References

  1. Häberle, M., et al. (2024). Fast-moving stars in ω Cen. Nature, 631, 285. arXiv:2405.06015
  2. Bañares-Hernández, A., et al. (2025). New constraints on OC central mass. A&A, 693, A104. doi:10.1051/0004-6361/202451763
  3. González Prieto, A., et al. (2025). Growing the IMBH in ω Cen. ApJL, 990, L69. arXiv:2507.06316
  4. Chen, S., et al. (2024). A census of MSPs in ω Cen with MeerKAT. MNRAS. (13 new MSPs discovered, total 18 confirmed)
  5. Freire, P. C. C., et al. (2017). Timing MSPs in globular clusters as IMBH probes. ApJ, 675, 670.
  6. Prager, B. J., et al. (2017). Using pulsars to probe the potential well of NGC 6752. ApJ, 845, 148. doi:10.3847/1538-4357/aa7ed7
  7. Perera, B. B. P., et al. (2019). The International Pulsar Timing Array: second data release. MNRAS, 490, 4666. doi:10.1093/mnras/stz2857
  8. Häberle, M., et al. (2025). oMEGACat VI — kinematic distance 5,494 ± 61 pc. ApJ, 983, 95. arXiv:2503.04903
Working draft · April 2026 · ← Return to omegacentauri.me

Relevant tools

Pulsar Timing Array
MSP timing residuals as mass probe
Velocity Dispersion
Stellar kinematics mass estimator
IMBH Evidence Dashboard
Live multi-constraint overview
Mass Segregation
Stellar mass function in OC core