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IC1101 Core

There is always more to learn about black holes. In college I had learned all the mass in a black hole is concentrated in a singularity, with zero radius, infinite density.

Now I find that IC1101, the largest visible galaxy has a very large core and it is special.

The abstract for a paper published to the Royal Astronomical Society about IC1101 had this:
'
The large core might be partly due to oscillatory core passages by a gravitational radiation-recoiled black hole.
'

I had not heard of that behavior before.

From an abstract (different paper) published at arXiv about this recoil apparently a black hole can be distorted by axisymmetric, but equatorial asymmetric gravitational (Brill) waves, net radiated energies. This distortion can generate the force for a recoil velocity.

How does a black hole singularity lose symmetry with zero radius, or have a positive net radiated energy through the event horizon? Maybe the paper invokes Hawkings radiation but not the abstract.

I know I am looking at only abstracts for published papers but I assume the abstract should attempt an accurate summary of the intent without revealing all the details.

I can find online references to
'
Radiation Recoil from spinning black hole mergers.'

from wikipedia:

'

Hawking radiation reduces the mass and energy of black holes and is therefore also known as black hole evaporation. Because of this, black holes that do not gain mass through other means are expected to shrink and ultimately vanish. '

Alternately this radiation eventually could result in a Micro black hole.

Einstein was quoted as saying: 'black holes are where god divided by zero.

I had assumed this was a reference to the proposed zero radius.

Apparently current black holes require more sophisticated math operations to achieve loss of symmetry with zero radius.

With Einstein all the mass in a single body universe was in the singularity.

Black holes are certainly evolving!
In 1974 Hawking radiation was proposed allowing radiation to get through the event horizon. Now we have such a variety: micro black hole, miniature black hole, intermediate black hole, stellar black hole, super massive  black hole often with companion stars and an accretion disk.
I can only wonder how well these gyrations reconcile with Einstein's original equations. We are told Einstein's theories have been confirmed but it seems new layers are being added fairly often so the original must have been inadequate.

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