What if Omega Centauri's central kinematics aren't caused by a single intermediate-mass black hole, but by a concentrated swarm of stellar-mass remnants? This tool models that hypothesis and shows where it is — and isn't — observationally distinguishable from the IMBH interpretation.
It models the leading non-IMBH explanation for ω Cen's central kinematic signature: a centrally-concentrated population of stellar-mass black holes and neutron stars, distributed according to a Plummer profile, rather than a single point-mass IMBH. You set the total remnant mass, the mean remnant mass, the Plummer scale radius, and the velocity anisotropy. The tool computes the enclosed-mass profile M(<r), plots it against an IMBH of comparable enclosed mass, and tells you whether current and near-future observations can actually tell the two apart.
The headline result, repeated for every parameter combination: at radii smaller than the Plummer scale (~0.1 pc), the two enclosed-mass profiles can be indistinguishable. That is the degeneracy that Bañares Hernández et al. 2025 made quantitative, and it's the reason the IMBH detection in ω Cen remains contested.
This isn't an ad-hoc model — it's what stellar dynamics predicts a cluster like ω Cen ought to contain. Over a few relaxation timescales (Spitzer 1987's Dynamical Evolution of Globular Clusters), heavier stellar remnants sink to the core via equipartition. The neutron stars and stellar-mass black holes produced over ω Cen's 12 Gyr history segregate into a tightly bound central sub-cluster. Direct N-body simulations (Breen & Heggie 2013, MNRAS 432:2779) predict that a cluster of ω Cen's mass and age should host on the order of 10³–10⁴ stellar-mass black holes in its core, with a total mass in the few-thousand-M☉ range. The Bañares model isn't reaching for an exotic alternative — it's pointing at what dynamical theory says should already be there.
ω Cen hosts a handful of known millisecond pulsars at projected radii of roughly 5″–20″ from the photometric centre (~0.13–0.53 pc). Pulsar timing residuals measure the gravitational pull of all mass interior to the pulsar's projected position. But at those radii, both scenarios — a single IMBH of mass M_BH, and a Plummer dark cluster with M_total ≈ M_BH and scale radius a ≲ 0.2 pc — produce nearly identical M_enc(<r). The two profiles only diverge appreciably for r < a, which is well inside the innermost pulsar. Pulsar timing alone therefore constrains the total central mass to good precision, but cannot tell you whether that mass is a point or a swarm. This is exactly the degeneracy the tool's right-hand readout makes explicit.
Three independent observations, in roughly the order they will arrive:
None of these were available when the Noyola 2008 and Häberle 2024 papers were written. The next decade settles it.
This tool sits in a small constellation. The IMBH Constraint Stacker overlays every published constraint on a single axis — the Bañares ceiling appears there as the upper edge of the dark-cluster-allowed region. The Pulsar Timing tool computes residuals for ω Cen's known MSPs and is where the "pulsar timing can't distinguish" claim becomes quantitative. The Orbital Dynamics tool handles the fast-moving stars side of the same argument.