APOD: 2025 May 4 Б Spin up of a Supermassive Black Hole
Explanation:
How fast can a black hole spin?
If any object made of regular matter spins too fast -- it breaks apart.
But a black hole might not be able to break apart --
and its maximum spin rate is really unknown.
Theorists usually model rapidly rotating black holes with the
Kerr solution to Einstein's
General Theory of Relativity,
which predicts several
amazing and
unusual things.
Perhaps its most easily testable prediction, though, is that matter entering a
maximally rotating black hole should be last seen
orbiting at near the speed of light, as seen from far away.
This prediction was tested by NASA's
NuSTAR and ESA's
XMM
satellites by observing the supermassive
black hole at the center of
spiral galaxy NGC 1365.
The near
light-speed limit was
confirmed by measuring the heating and
spectral line broadening
of nuclear emissions at the inner edge of the surrounding
accretion disk.
Pictured
here is an artist's illustration
depicting an accretion disk of normal
matter swirling around a black hole, with a
jet emanating from the top.
Since matter randomly falling
into the black hol
e
should not spin up a black hole this much,
the NuSTAR and XMM measurements also validate the existence of the
surrounding accretion disk.
Hole New Worlds:
It's Black Hole Week at NASA!
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
