Galaxy Morphometry & Rotation Lab

Astrophysics Simulator
Sb Spiral Galaxy
Particles: 50,000
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Hubble Sequence Presets Sb
Galactic Mass & Dark Matter
Dark Matter Halo Ratio 5.5x
Baryonic Stellar Mass (10¹⁰ M☉) 10.0
Disk Scale Length (kpc) 3.5
Orbital Rotation Curve V(r)
Keplerian Decay (Baryonic)
Observed (Baryonic + DM)
Morphology & Arms
Spiral Arm Count 2
Pitch Angle (Deg) 14.5°
Bulge-to-Disk Ratio 0.25
Doppler Absorption Spectrograph

H-Alpha Line-of-sight Shift Across Disk Diameter

Galactic Diagnostics
Total Mass
6.50e11 M☉
Outer Speed V(r_max)
215.2 km/s
Keplerian Falloff
88.5 km/s
DM Halo Virial Radius
200.0 kpc
What is a Galaxy?
A galaxy is a gravitationally bound cosmic system of stars, gas, and dark matter. Without a dominant Dark Matter Halo, galactic disk speed decays Keplerian-style (~1/√r). With dark matter (5.5x baryonic mass), outer rotation speed remains flat at ~215.2 km/s.