= Accretion-disk tests of strong-field gravity
Radiating material close to a compact object probes relativistic orbital motion, <gravitational redshift> and light propagation. A thin disk's inferred inner edge can be compared with the predicted <innermost stable circular orbit>, while iron-line transfer and thermal-continuum fitting probe complementary aspects of the same geometry. Agreement tests a combined spacetime-and-disk model. A <black-hole spin> measurement made after imposing a <Kerr metric> is not alone an independent verification of that <metric tensor>; geometry tests must vary gravitational predictions and astrophysical nuisance parameters together.
Back to article page
