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Record-breaking supermassive black hole found in heart of far-off galaxy

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  Record-breaking supermassive black hole found in heart of far-off galaxy Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2016-02-12 11:21 -0500
    Re: Record-breaking supermassive black hole found in heart of far-off galaxy Odd Bodkin <bodkinodd@gmail.com> - 2016-02-12 10:26 -0600
      Re: Record-breaking supermassive black hole found in heart of far-off galaxy Mike Duffy <Invalid@no_such_domain.com> - 2016-02-12 11:56 -0500
        Re: Record-breaking supermassive black hole found in heart of far-off galaxy Odd Bodkin <bodkinodd@gmail.com> - 2016-02-12 11:09 -0600
        Re: Record-breaking supermassive black hole found in heart of far-off galaxy Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-02-13 01:37 +0100
    Re: Record-breaking supermassive black hole found in heart of far-off galaxy Sam Wormley <swormley1@gmail.com> - 2016-02-12 11:02 -0600

#552526 — Record-breaking supermassive black hole found in heart of far-off galaxy

A supermassive black hole — with the mass 21 billion times that of our 
own sun — has been found at the heart of a distant galaxy.

NGC 4889 is an elliptical galaxy. Rather than being the galaxy most 
people think of, elliptical galaxies look like they have no real 
structure, with their collection of stars looking more like blobs in space.

The galaxy is about 300 million light years away, in the heart of a 
galaxy cluster known as the Coma Cluster. The black hole has an event 
horizon — a location where not even light can escape — with diameter of 
130 billion km. That’s approximately the distance between the sun and 
Neptune, the last planet in our solar system. Comparatively, the black 
hole at the heart of our galaxy has an event horizon about one-fifth the 
orbit of Mercury, the closest planet to the sun and a mass of about four 
million times that of the sun.

Astronomers believe that the black hole is no longer gobbling up matter. 
In fact, they believe that stars have begun to form in the surrounding 
region.

http://globalnews.ca/news/2511541/record-breaking-supermassive-black-hole-found-in-heart-of-far-off-galaxy/

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#552530

On 2/12/2016 10:21 AM, Yousuf Khan wrote:
> A supermassive black hole — with the mass 21 billion times that of our
> own sun — has been found at the heart of a distant galaxy.
>
> NGC 4889 is an elliptical galaxy. Rather than being the galaxy most
> people think of, elliptical galaxies look like they have no real
> structure, with their collection of stars looking more like blobs in space.
>
> The galaxy is about 300 million light years away, in the heart of a
> galaxy cluster known as the Coma Cluster. The black hole has an event
> horizon — a location where not even light can escape — with diameter of
> 130 billion km. That’s approximately the distance between the sun and
> Neptune, the last planet in our solar system. Comparatively, the black
> hole at the heart of our galaxy has an event horizon about one-fifth the
> orbit of Mercury, the closest planet to the sun and a mass of about four
> million times that of the sun.
>
> Astronomers believe that the black hole is no longer gobbling up matter.
> In fact, they believe that stars have begun to form in the surrounding
> region.
>
> http://globalnews.ca/news/2511541/record-breaking-supermassive-black-hole-found-in-heart-of-far-off-galaxy/
>

Note, John Sefton, that black holes are not presented in GR as things 
that swallow everything in their vicinity, and that star formation in 
the region outside a black hole is perfectly consistent with general 
relativity.

No matter what magazine article you think you might have read sometime 
that suggested to you otherwise.

-- 
Odd Bodkin --- maker of fine toys, tools, tables

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#552537

On Fri, 12 Feb 2016 10:26:28 -0600, Odd Bodkin wrote:

> Note, John Sefton, that black holes are not presented in GR as things 
> that swallow everything in their vicinity, and that star formation in 
> the region outside a black hole is perfectly consistent with general 
> relativity.

How does that work? My limited understanding of the mechanism for black
holes emitting matter via 'Hawking' radiation works best for black holes
just barely big enough to hold thenselves together. Bigger ones would thus
emit less.

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#552541

On 2/12/2016 10:56 AM, Mike Duffy wrote:
> On Fri, 12 Feb 2016 10:26:28 -0600, Odd Bodkin wrote:
>
>> Note, John Sefton, that black holes are not presented in GR as things
>> that swallow everything in their vicinity, and that star formation in
>> the region outside a black hole is perfectly consistent with general
>> relativity.
>
> How does that work? My limited understanding of the mechanism for black
> holes emitting matter via 'Hawking' radiation works best for black holes
> just barely big enough to hold thenselves together. Bigger ones would thus
> emit less.
>

Because of the gravitational pull of the black hole, matter can accrete 
outside the black hole's event horizon WITHOUT being sucked in. This is 
for the same reason that the matter in the rings of Saturn accrete in 
those rings without falling into Saturn, and for the same reason the 
asteroid belt orbits the sun without falling into the sun.

If the density of the accretion is high enough, you can seed stars.

If the black hole has angular momentum, then you can also get effects 
that come from the rotation of the orbiting matter, such as magnetic 
fields and ejected jets along the axis.

None of this has anything to do with Hawking radiation, which (as you 
say) is tiny, tiny, tiny for a supermassive black hole.

-- 
Odd Bodkin --- maker of fine toys, tools, tables

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#552655

Mike Duffy wrote:

> On Fri, 12 Feb 2016 10:26:28 -0600, Odd Bodkin wrote:
>> Note, John Sefton, that black holes are not presented in GR as things
>> that swallow everything in their vicinity, and that star formation in
>> the region outside a black hole is perfectly consistent with general
>> relativity.
> 
> How does that work?

Very simple.  An object has to *pass* the event horizon of a black hole in 
order to be “swallowed” by it.  That does not happen if the object is far 
enough away from the event horizon and/or has an orbital speed that is high 
enough.  For example, light can circulate forever around a black hole on a 
trajectory outside the event horizon called the “photon sphere”.

Popular-scientific version: <https://www.youtube.com/watch?v=eI9CvipHl_c>
Corresponding science: <http://jila.colorado.edu/~ajsh/insidebh/>

> My limited understanding of the mechanism for black holes emitting matter
> via 'Hawking' radiation works best for black holes just barely big enough
> to hold thenselves together. Bigger ones would thus emit less.

Hawking radiation – which AFAIK is yet to be detected – has nothing to do 
with this.

<https://en.wikipedia.org/wiki/Hawking_radiation>


X-Post & F'up2 <news:sci.physics.relativity>

PointedEars
-- 
Q: Who's on the case when the electricity goes out?  
A: Sherlock Ohms.

(from: WolframAlpha)

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#552539

On 2/12/16 10:21 AM, Yousuf Khan wrote:
> A supermassive black hole — with the mass 21 billion times that of our
> own sun — has been found at the heart of a distant galaxy.
>
> NGC 4889 is an elliptical galaxy. Rather than being the galaxy most
> people think of, elliptical galaxies look like they have no real
> structure, with their collection of stars looking more like blobs in space.
>
> The galaxy is about 300 million light years away, in the heart of a
> galaxy cluster known as the Coma Cluster. The black hole has an event
> horizon — a location where not even light can escape — with diameter of
> 130 billion km. That’s approximately the distance between the sun and
> Neptune, the last planet in our solar system. Comparatively, the black
> hole at the heart of our galaxy has an event horizon about one-fifth the
> orbit of Mercury, the closest planet to the sun and a mass of about four
> million times that of the sun.
>
> Astronomers believe that the black hole is no longer gobbling up matter.
> In fact, they believe that stars have begun to form in the surrounding
> region.
>
> http://globalnews.ca/news/2511541/record-breaking-supermassive-black-hole-found-in-heart-of-far-off-galaxy/
>


   Thanks for posting this.


-- 

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