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New technique for measuring black hole mass, yields universe's smallestblack hole ever



 
 
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  #1  
Old December 11th 09, 07:22 PM posted to sci.astro,sci.physics
Yousuf Khan[_2_]
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Posts: 1,692
Default New technique for measuring black hole mass, yields universe's smallestblack hole ever

Smallest Black Hole Ever Discovered Has Amazing Tidal Force
"The method used by Shaposhnikov and Titarchuk has been described in
several papers in the Astrophysical Journal. It uses a relationship
between black holes and the inner part of their surrounding disks, where
gas spirals inward before making the fatal plunge. When the feeding
frenzy reaches a moderate rate, hot gas piles up near the black hole and
radiates a torrent of X-rays. The X-ray intensity varies in a pattern
that repeats itself over a nearly regular interval. This signal is
called a quasi-periodic oscillation, or QPO.

Astronomers have long suspected that a QPO's frequency depends on the
black hole's mass. In 1998, Titarchuk realized that the congestion zone
lies close in for small black holes, so the QPO clock ticks quickly. As
black holes increase in mass, the congestion zone is pushed farther out,
so the QPO clock ticks slower and slower. To measure the black hole
masses, Shaposhnikov and Titarchuk use archival data from RXTE, which
has made exquisitely precise measurements of QPO frequencies in at least
15 black holes."
http://www.sciencedaily.com/releases...0401141549.htm
  #2  
Old December 11th 09, 10:10 PM posted to sci.astro,sci.physics
Uncle Al
external usenet poster
 
Posts: 697
Default New technique for measuring black hole mass, yields universe'ssmallestblack hole ever

Yousuf Khan wrote:

Smallest Black Hole Ever Discovered Has Amazing Tidal Force
"The method used by Shaposhnikov and Titarchuk has been described in
several papers in the Astrophysical Journal. It uses a relationship
between black holes and the inner part of their surrounding disks, where
gas spirals inward before making the fatal plunge. When the feeding
frenzy reaches a moderate rate, hot gas piles up near the black hole and
radiates a torrent of X-rays. The X-ray intensity varies in a pattern
that repeats itself over a nearly regular interval. This signal is
called a quasi-periodic oscillation, or QPO.

Astronomers have long suspected that a QPO's frequency depends on the
black hole's mass. In 1998, Titarchuk realized that the congestion zone
lies close in for small black holes, so the QPO clock ticks quickly. As
black holes increase in mass, the congestion zone is pushed farther out,
so the QPO clock ticks slower and slower. To measure the black hole
masses, Shaposhnikov and Titarchuk use archival data from RXTE, which
has made exquisitely precise measurements of QPO frequencies in at least
15 black holes."
http://www.sciencedaily.com/releases...0401141549.htm


Two fun parts: First, if the binary system's orbit is accurately
described by General Relativity, black holes obey the Equivalence
Principle. Second, the mass of the black hole is vastly smaller than
the summed masses of separated baryons that condensed to form it -
gravitational binding energy.

1.74 solar-mass pulsar PSR J1903+0327 is in a 95.17-day
0.437-eccentricity orbit with its 1.05 solar-mass star companion.
Respective gravitational binding energies are 27% vs. 1.4x10^(-4)%.
Thus the neutron star assembled from 2.38 solar masses.

What is the gravitational binding energy of the black hole?

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm
  #3  
Old December 12th 09, 01:23 AM posted to sci.astro,sci.physics
eric gisse
external usenet poster
 
Posts: 342
Default New technique for measuring black hole mass, yields universe's smallest black hole ever

Yousuf Khan wrote:

Smallest Black Hole Ever Discovered Has Amazing Tidal Force
"The method used by Shaposhnikov and Titarchuk has been described in
several papers in the Astrophysical Journal. It uses a relationship
between black holes and the inner part of their surrounding disks, where
gas spirals inward before making the fatal plunge. When the feeding
frenzy reaches a moderate rate, hot gas piles up near the black hole and
radiates a torrent of X-rays. The X-ray intensity varies in a pattern
that repeats itself over a nearly regular interval. This signal is
called a quasi-periodic oscillation, or QPO.


This is not new.

We have been measuring black hole mass and spin via this method for probably
close to a decade now. This has the irritating feature of being a model
dependent prediction as the nature of the oscillations depend on what's
being assumed.

The current working theory for accretion dynamics is the radiatively
inefficient accretion flow [RIAF] model.


Astronomers have long suspected that a QPO's frequency depends on the
black hole's mass. In 1998, Titarchuk realized that the congestion zone
lies close in for small black holes, so the QPO clock ticks quickly. As
black holes increase in mass, the congestion zone is pushed farther out,
so the QPO clock ticks slower and slower. To measure the black hole
masses, Shaposhnikov and Titarchuk use archival data from RXTE, which
has made exquisitely precise measurements of QPO frequencies in at least
15 black holes."
http://www.sciencedaily.com/releases...0401141549.htm


The only new thing about this is that it is confirmed over a wider scale of
black hole masses. Still interesting, which is why I'm ****ed off I couldn't
find it at the UW library.

Then again, I was looking at the wrong year since it was published in TWO
THOUSAND ****ING EIGHT. Thanks for the current event.

  #4  
Old December 12th 09, 01:25 AM posted to sci.astro,sci.physics
eric gisse
external usenet poster
 
Posts: 342
Default New technique for measuring black hole mass, yields universe's smallestblack hole ever

Uncle Al wrote:

Yousuf Khan wrote:

Smallest Black Hole Ever Discovered Has Amazing Tidal Force
"The method used by Shaposhnikov and Titarchuk has been described in
several papers in the Astrophysical Journal. It uses a relationship
between black holes and the inner part of their surrounding disks, where
gas spirals inward before making the fatal plunge. When the feeding
frenzy reaches a moderate rate, hot gas piles up near the black hole and
radiates a torrent of X-rays. The X-ray intensity varies in a pattern
that repeats itself over a nearly regular interval. This signal is
called a quasi-periodic oscillation, or QPO.

Astronomers have long suspected that a QPO's frequency depends on the
black hole's mass. In 1998, Titarchuk realized that the congestion zone
lies close in for small black holes, so the QPO clock ticks quickly. As
black holes increase in mass, the congestion zone is pushed farther out,
so the QPO clock ticks slower and slower. To measure the black hole
masses, Shaposhnikov and Titarchuk use archival data from RXTE, which
has made exquisitely precise measurements of QPO frequencies in at least
15 black holes."
http://www.sciencedaily.com/releases...0401141549.htm


Two fun parts: First, if the binary system's orbit is accurately
described by General Relativity, black holes obey the Equivalence
Principle. Second, the mass of the black hole is vastly smaller than
the summed masses of separated baryons that condensed to form it -
gravitational binding energy.

1.74 solar-mass pulsar PSR J1903+0327 is in a 95.17-day
0.437-eccentricity orbit with its 1.05 solar-mass star companion.
Respective gravitational binding energies are 27% vs. 1.4x10^(-4)%.
Thus the neutron star assembled from 2.38 solar masses.

What is the gravitational binding energy of the black hole?


What's the meaning of the term for a black hole?

You can't disassemble the construct to provide a valid comparison. The only
mass for a black hole that matters is its' gravitational mass.
  #5  
Old December 12th 09, 01:54 AM posted to sci.astro
Yousuf Khan[_2_]
external usenet poster
 
Posts: 1,692
Default New technique for measuring black hole mass, yields universe'ssmallest black hole ever

eric gisse wrote:
Yousuf Khan wrote:

Smallest Black Hole Ever Discovered Has Amazing Tidal Force
"The method used by Shaposhnikov and Titarchuk has been described in
several papers in the Astrophysical Journal. It uses a relationship
between black holes and the inner part of their surrounding disks, where
gas spirals inward before making the fatal plunge. When the feeding
frenzy reaches a moderate rate, hot gas piles up near the black hole and
radiates a torrent of X-rays. The X-ray intensity varies in a pattern
that repeats itself over a nearly regular interval. This signal is
called a quasi-periodic oscillation, or QPO.


This is not new.

We have been measuring black hole mass and spin via this method for probably
close to a decade now. This has the irritating feature of being a model
dependent prediction as the nature of the oscillations depend on what's
being assumed.


Which seems to be close to what was stated in the article.

Astronomers have long suspected that a QPO's frequency depends on the
black hole's mass. In 1998, Titarchuk realized that the congestion zone
lies close in for small black holes, so the QPO clock ticks quickly. As
black holes increase in mass, the congestion zone is pushed farther out,
so the QPO clock ticks slower and slower. To measure the black hole
masses, Shaposhnikov and Titarchuk use archival data from RXTE, which
has made exquisitely precise measurements of QPO frequencies in at least
15 black holes."
http://www.sciencedaily.com/releases...0401141549.htm


The only new thing about this is that it is confirmed over a wider scale of
black hole masses. Still interesting, which is why I'm ****ed off I couldn't
find it at the UW library.

Then again, I was looking at the wrong year since it was published in TWO
THOUSAND ****ING EIGHT. Thanks for the current event.


It's a year old, but still current, since I haven't seen anything newer
about it.

Yousuf Khan
 




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