Modified gravity (MOG) and the cluster Abell 1689 acceleration data

Understand

The galaxy cluster system Abell 1689 has been well studied and yields good lensing and X-ray gas data.

• Modified gravity (MOG) is applied to the cluster Abell 1689 and the acceleration data is well fitted without assuming dark matter.
• Newtonian dynamics and Modified Newtonian dynamics (MOND) are shown not to fit the acceleration data, while a dark matter model based on the Navarro-Frenk-White (NFW) mass profile is shown to fit the acceleration data for the radial range $r > 200$ kpc.