Event-horizon silhouette
A central dark sphere marks the compact-object boundary scale. It is visually enlarged relative to the surrounding system so the scene can be studied on a screen.
Black-hole field guide
TON 618 as a compact-object study target.
A luminous quasar powered by hot accreting gas around an extremely massive central compact object.
TON 618 - Ultramassive quasar black-hole candidate
Catalog identity
Observed and inferred properties
Observation basis
How the black hole is inferred
Inferred from quasar spectroscopy, broad emission lines, luminosity, redshift, and accretion modeling rather than direct horizon imaging.
Treat TON 618 as an extreme mass estimate with systematic uncertainty. The page avoids presenting a single exact event-horizon image because none exists.
Simulation Layers
What the WebGL scene shows
Photon-ring cue
The bright ring is a lensing-inspired visual layer that explains why near-horizon light can wrap around the compact object.
Accretion flow
Rotating disk particles show hot gas losing angular momentum. Disk color and thickness vary by black-hole class.
Jets and outflows
Targets with active nuclei or microquasar behavior show collimated jet cones; quiet/dormant targets omit the jet layer.
Scale compression
The model compresses event-horizon, disk, binary, galaxy, and light-year scales into a readable study frame.
Main simulator
The object is also selectable from the 3D Space Lab deep-space focus list.
Physics explanation
What controls the appearance
Black holes are observed by their influence: gravity, accretion, jets, hot gas spectra, stellar motion, binary dynamics, and lensing. The visible dark center is not a surface. It is a one-way causal boundary surrounded by curved spacetime and, when fuel is present, rapidly orbiting plasma.
Review caution
What not to over-read
Bright disk, dense broad-line glow, and scaled twin jets. The horizon scale is compressed against the much larger quasar environment.
The visualization is deliberately lightweight for public web performance. It is a physics-oriented diagram in 3D, not a general-relativistic magnetohydrodynamics simulation or a direct telescope image.
Mathematical model
Black-hole and accretion-disk model
Black-hole visuals use theoretical scaling equations for the event horizon, photon-ring marker, and optically thick accretion disk. They are educational WebGL approximations, not numerical general-relativistic ray-tracing renders.
Event-horizon scale
\[R_s=\frac{2GM}{c^2}\]
The black silhouette is scaled from the Schwarzschild radius relation. Mass changes the horizon scale through G, M, and c, not through image tracing.
Thin-disk temperature
\[T(r)^4 \propto r^{-3}\left[1-\sqrt{\frac{R_{\mathrm{in}}}{r}}\right]\]
The annular disk brightness and color are assigned from the standard steady thin-disk radial profile, so inner rings are hotter and outer rings cool by equation.
Keplerian disk flow
\[\Omega(r)=\sqrt{\frac{GM}{r^3}}\]
Orbiting gas is represented as differentially rotating annuli and flow bands. The visual proof is that angular speed decreases with radius as Keplerian motion requires.
Verification standard: the rendered object must be reproducible from stated equations, catalog parameters, or explicit geometric transforms. Visual reference images may inform presentation only; they are not the source of orbital positions, field vectors, accretion-disk gradients, timing, or engineering layout.
Limitations: browser scenes may use bounded scale, compressed distances, simplified two-body dynamics, schematic transfer curves, or educational approximations where full numerical ephemerides, CFD, finite-element models, or general-relativistic ray tracing are outside the page scope. Those simplifications are part of the model contract, not hidden image-based construction.