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Active galaxy jets may be due to blackholes spinning backwards fromtheir accretion disks



 
 
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  #1  
Old February 11th 10, 09:18 AM posted to sci.astro,sci.physics
Yousuf Khan[_2_]
external usenet poster
 
Posts: 1,692
Default Active galaxy jets may be due to blackholes spinning backwards fromtheir accretion disks

For two years, Evans has been comparing several dozen galaxies whose
black holes host powerful jets (these galaxies are known as radio-loud
active galactic nuclei, or AGN) to those galaxies with supermassive
black holes that do not eject jets. All black holes — those with and
without jets — feature accretion disks, the clumps of dust and gas
rotating just outside the event horizon. By examining the light
reflected in the accretion disk of an AGN black hole, he concluded that
jets may form right outside black holes that have a retrograde spin — or
which spin in the opposite direction from their accretion disk. Although
Evans and a colleague recently hypothesized that the gravitational
effects of black hole spin may have something to do with why some have
jets, Evans now has observational results to support the theory in a
paper published in the Feb. 10 issue of the Astrophysical Journal.

***snip***

Although Evans has suspected for nearly five years that retrograde black
holes with jets are missing the innermost portion of their accretion
disk, it wasn’t until last year that computational advances meant that
he could analyze data collected between late 2007 and early 2008 by the
Suzaku observatory, a Japanese satellite launched in 2005 with
collaboration from NASA, to provide an example to support the theory.
With these data, Evans and colleagues from the Harvard-Smithsonian
Center for Astrophysics, Yale University, Keele University and the
University of Hertfordshire in the United Kingdom analyzed the spectra
of a supermassive black hole with a jet located about 800 million light
years away in an AGN named 3C 33.

***

Unraveling black hole spin
http://web.mit.edu/newsoffice/2010/black-hole-jets.html
  #2  
Old February 11th 10, 11:06 AM posted to sci.astro,sci.physics
eric gisse
external usenet poster
 
Posts: 342
Default Active galaxy jets may be due to blackholes spinning backwards from their accretion disks

Yousuf Khan wrote:

[...]

Not a ****ing chance.

The spin of the black hole will drive the accretion flow backwards from
whatever retrograde orbit it had before, drop it into the black hole, and
carry what's left around with the hole's angular momentum. There's a strong
selection process in play here.

The a near-maximal spin black hole will nearly half the distance inwards the
innermost circular orbit sits with respect to the same orbit for a non-
rotating black hole. The frame dragging effect literally does drag particles
along for the ride when you are within a few Schwarzschild radii of a
spinning black hole, as the inner part of accretion flows tend to be. Spin
of a supermassive black hole isn't a trivial effect.

This is no direct observation of accretion flow. Nor is it a measurement or
even indirect guess at the spin of the black hole *OR* what ****ing
direction it goes in.

No GRMHD simulations, just the nonexistence of X-ray backscatter. What the
hell?

I'm highly interested in reading the full scholarly article but this looks
like rather speculative guessing to me. I might go down to UW just for this.
  #3  
Old February 11th 10, 03:50 PM posted to sci.astro,sci.physics
bert
external usenet poster
 
Posts: 1,997
Default Active galaxy jets may be due to blackholes spinning backwardsfrom their accretion disks

On Feb 11, 3:18*am, Yousuf Khan wrote:
For two years, Evans has been comparing several dozen galaxies whose
black holes host powerful jets (these galaxies are known as radio-loud
active galactic nuclei, or AGN) to those galaxies with supermassive
black holes that do not eject jets. All black holes — those with and
without jets — feature accretion disks, the clumps of dust and gas
rotating just outside the event horizon. By examining the light
reflected in the accretion disk of an AGN black hole, he concluded that
jets may form right outside black holes that have a retrograde spin — or
which spin in the opposite direction from their accretion disk. Although
Evans and a colleague recently hypothesized that the gravitational
effects of black hole spin may have something to do with why some have
jets, Evans now has observational results to support the theory in a
paper published in the Feb. 10 issue of the Astrophysical Journal.

***snip***

Although Evans has suspected for nearly five years that retrograde black
holes with jets are missing the innermost portion of their accretion
disk, it wasn’t until last year that computational advances meant that
he could analyze data collected between late 2007 and early 2008 by the
Suzaku observatory, a Japanese satellite launched in 2005 with
collaboration from NASA, to provide an example to support the theory.
With these data, Evans and colleagues from the Harvard-Smithsonian
Center for Astrophysics, Yale University, Keele University and the
University of Hertfordshire in the United Kingdom analyzed the spectra
of a supermassive black hole with a jet located about 800 million light
years away in an AGN named 3C 33.

***

Unraveling black hole spinhttp://web.mit.edu/newsoffice/2010/black-hole-jets.html


Khan The giant elliptical galaxy M82(known as Virgo) gives reality to
your post. Trebert
  #4  
Old February 11th 10, 09:11 PM posted to sci.physics,sci.astro
dlzc
external usenet poster
 
Posts: 1,426
Default Active galaxy jets may be due to blackholes spinning backwardsfrom their accretion disks

Dear john:

On Feb 11, 8:19*am, john wrote:
On Feb 11, 8:58*am, dlzc wrote:
On Feb 11, 3:06*am, eric gisse wrote:


Yousuf Khan wrote:


[...]


Not a ****ing chance.


The spin of the black hole will drive the accretion flow
backwards from whatever retrograde orbit it had before,
drop it into the black hole, and carry what's left around
with the hole's angular momentum. There's a strong
selection process in play here.


That is what the paper said, Eric. *The "selection
process" left a noticeable void around the black hole,
as stuff simply fell in. *No chance to get reboosted from
original momentum to exactly counter momentum.


...


I'm highly interested in reading the full scholarly article
but this looks like rather speculative guessing to me. I
might go down to UW just for this.


Let us know what you find. *Your shoes need to trod that
ground again anyway...


I tread, I trod, I have trodden

Black holes separate charge for infalling matter
and shoot positives out one
jet and negatives out the other.
*Does it ionize?


Does a "traffic jam", then then "infinite" series of collisions,
produce noise and flying bits?

If we have charged particle separation then we'd require a charged
central hole as well, it would seem. Our own central black hole is
spawning antiparticles from one pole too. Wonder how that works? How
do you polarize antiparticle creation...

Maybe a BH with jets is really a white hole, only its only white on an
axis? Nah!

David A. Smith
  #5  
Old February 12th 10, 01:45 AM posted to sci.physics,sci.astro,sci.physics.research
eric gisse
external usenet poster
 
Posts: 342
Default Active galaxy jets may be due to blackholes spinning backwardsfrom their accretion disks

dlzc wrote:
[...]

For the uninitiated: the article in question is "THE HARD X-RAY VIEW OF
REFLECTION, ABSORPTION, AND THE DISK-JET CONNECTION IN THE RADIO-LOUD AGN 3C
33"; D. Evans, et.al., ApJ 710 p859.

The reason I'm bothering is because of an eye raising article, I mean *press
release*, by MIT which happens to make an interesting claim about the source
of jetting for active galactic nuclei (AGN)...

MIT happens to be Evans' hosting institution.

http://web.mit.edu/newsoffice/2010/black-hole-jets.html

I'm highly interested in reading the full scholarly article
but this looks like rather speculative guessing to me. I
might go down to UW just for this.


Let us know what you find. Your shoes need to trod that ground again
anyway...


Walking to UW to borrow their institutional access to ApJ, MNRAS, Phys. Rev.
D, Science, Nature, etc is a part of my weekly ritual.

The Feb. 10 issue of ApJ was already trawled over by me, and I still have a
bunch of articles I downloaded last week that I have not yet read. But the
Evans article is not in that pile, because the blurb on the ApJ site (which
mirrors what they put on print) is not interesting.

ApJ in print form, for an entire month, is roughly 4 inches thick give or
take. The index, double sided, is six pages with a one sentence blurb about
the research. This is something people do not realize.

The observations are based on surveys by X-ray telescopes (Suzaku, XMM-
Newton, Chandra, Swift). This tells you immediately that there are no direct
observations of the region in question like how VLBI imagery directly
surveyed the area around Sgr. A*. There is nothing suspect about the
observations, as far as I can tell. Though I note with perpetual amusement
that there have to be corrections to events recorded by the satellites as
they pass through the South Atlantic Anomaly.

Speculation that there is no inner reflective surface is based on the non-
observation of the Iron-alpha emission lines. For reference, the two lines
are a 6.404 and 6.391 (from my notes..) doublet that show up rather
prominently and have been used for a very long time as a strong diagnostic
of 'what is going on' in accretion regions. Given that the AGN is only at z
=~0.03, there's an expectation of Iron being present.

Though the methodology that says there is no reflection, while not 'wrong',
is certainly up for debate.

Simple fitting of what the telescopes observe are consistent with a power
law spectrum that has some absorbing properties. No big surprise there -
power law spectrae are par for the course when it comes to astrophysics, and
absorbing of light is not a shocker when it comes to ionized locales.

What a straight reading of this one piece of scholarly research does not
indicate is that there is a super, super, SUPER strong coupling between the
inclination angle of the accretion disk and what is observed on Earth.
Furthermore, even a reasonable fit on the angle is ****ing hard to make even
for close and cooperative regions in which a wide variety of wavelengths are
available. So when Evans assumes a 60 degree angle for the inclination,
without sourcing it, it raises an eyebrow.

Also, Evans uses a simulation called 'reflexionx' for modeling the X-ray
spectrum. That raises another eyebrow because in "Measuring the spin of
GRS1915+105 with relativistic disk reflection"; J. Blum et.al., ApJ 706 p60
(the subject should tell you this ties in), it was found that the reflexionx
model was giving results for the spin parameter that were inconsistent with
previous works on the subject using equivalent data sets. So I'll smack
anyone who makes a serious argument using this paper's interpretations of
the data unless some very fancy footwork is done.

This tells you everything you need to know:

"Our results demonstrate that 3C 33 shows no signs of Compton
reflection from neutral material in the inner regions of an
accretion disk: there is no reflection hump at energies 10 keV,
and no evidence for relativistically broadened Fe K? emission
(Model VII)."

I fully expect that the inner part of accretion flow is mostly plasma, and I
thought that before it was later pointed out that all the data is consistent
with an ionized accretion flow.

The thing that I really, really wanted to see was a substantiation of the
claim that retrograde accretion flow with respect to the spin of the black
hole could *happen*, and explain what's seen.

"The X-ray spectrum of 3C 33 is also consistent with the picture
of Garofalo et al. (2009). They argue the jet power of high-
excitation radio galaxies such as 3C 33 is the result of
retrograde black-hole spin with respect to the accreting material.
This configuration results in a larger innermost circular stable
orbit than for a prograde black hole. The weak or absent
signatures of reflection in 3C 33, then, are simply a consequence
of the large inner disk radius."

My opinion on this has not changed. At all. I do not see how it is
physically possible, much less plausible.

Furthermore, the direction in which a Kerr black hole rotates has an
abundance of ****-all to do with the radius of the innermost stable orbit
for massive particles. So it is my very, very strong personal opinion that
the claim that a black hole spinning in one direction versus another
direction has anything to do with the location of the innermost stable
circular orbit.

I really, REALLY wanted to read Garofalo (2009), but it doesn't exist. I'm
substantially irritated that the only substantiation of the theory was a one
paragraph blurb that references an article that doesn't exist yet.

"Garofalo, D., Evans, D. A., & Sambruna, R. M. 2009, MNRAS,
submitted"

That Evans is second author on that reference makes me wonder ever so
slightly. Especially since not once in my ever-larger reading on this
subject have I ever seen the idea that retrograde accretion flow can exist,
much less do what is claimed.

I've made a note in my notebook on this, and I'll keep a lookout for the
article in MNRAS but I'm highly skeptical at this point.

People sometimes wonder how the time I spend on this newsgroup manifests
itself. This oughta clear that up.


David A. Smith


  #6  
Old February 12th 10, 04:07 AM posted to sci.physics,sci.astro
john
external usenet poster
 
Posts: 112
Default Active galaxy jets may be due to blackholes spinning backwardsfrom their accretion disks

On Feb 11, 2:11*pm, dlzc wrote:
Dear john:

On Feb 11, 8:19*am, john wrote:





On Feb 11, 8:58*am, dlzc wrote:
On Feb 11, 3:06*am, eric gisse wrote:


Yousuf Khan wrote:


[...]


Not a ****ing chance.


The spin of the black hole will drive the accretion flow
backwards from whatever retrograde orbit it had before,
drop it into the black hole, and carry what's left around
with the hole's angular momentum. There's a strong
selection process in play here.


That is what the paper said, Eric. *The "selection
process" left a noticeable void around the black hole,
as stuff simply fell in. *No chance to get reboosted from
original momentum to exactly counter momentum.


...


I'm highly interested in reading the full scholarly article
but this looks like rather speculative guessing to me. I
might go down to UW just for this.


Let us know what you find. *Your shoes need to trod that
ground again anyway...


I tread, I trod, I have trodden


Black holes separate charge for infalling matter
and shoot positives out one
jet and negatives out the other.
*Does it ionize?


Does a "traffic jam", then then "infinite" series of collisions,
produce noise and flying bits?

If we have charged particle separation then we'd require a charged
central hole as well, it would seem. *Our own central black hole is
spawning antiparticles from one pole too. *Wonder how that works? *How
do you polarize antiparticle creation...

Maybe a BH with jets is really a white hole, only its only white on an
axis? *Nah!

David A. Smith- Hide quoted text -

- Show quoted text -


How many antiparticles?

My assumption was one charge out one pole,
the other out the other.

john
  #7  
Old February 12th 10, 04:51 AM posted to sci.physics,sci.astro
eric gisse
external usenet poster
 
Posts: 342
Default Active galaxy jets may be due to blackholes spinning backwards from their accretion disks

john wrote:

[...]

My assumption was one charge out one pole,
the other out the other.

john


a) The greatest barrier to knowledge is not ignorance but the illusion of
knowledge.
b) Kruger-Dunning effect.


  #8  
Old February 12th 10, 03:30 PM posted to sci.physics,sci.astro
dlzc
external usenet poster
 
Posts: 1,426
Default Active galaxy jets may be due to blackholes spinning backwardsfrom their accretion disks

Dear john:

On Feb 11, 8:07*pm, john wrote:
On Feb 11, 2:11*pm, dlzc wrote:

....
If we have charged particle separation then we'd
require a charged central hole as well, it would
seem. *Our own central black hole is spawning
antiparticles from one pole too. *Wonder how that
works? *How do you polarize antiparticle creation...


How many antiparticles?

My assumption was one charge out one pole,
the other out the other.


This says no antimatter:
http://www.physorg.com/news79361214.html

These say antimatter:
http://adsabs.harvard.edu/abs/2002cosp...34E3251T
http://web.mit.edu/dvp/www/Work/8.22....224-paper.pdf
http://www.nustar.caltech.edu/about-...lky-way-galaxy

The signature of matter / antimatter annihilations is seen on only one
jet.

David A. Smith
  #9  
Old February 12th 10, 08:27 PM posted to sci.astro
John Park
external usenet poster
 
Posts: 155
Default Active galaxy jets may be due to blackholes spinning backwards from their accretion disks

eric gisse ) writes:
dlzc wrote:
[...]

For the uninitiated: the article in question is "THE HARD X-RAY VIEW OF
REFLECTION, ABSORPTION, AND THE DISK-JET CONNECTION IN THE RADIO-LOUD AGN 3C
33"; D. Evans, et.al., ApJ 710 p859.

The reason I'm bothering is because of an eye raising article, I mean *press
release*, by MIT which happens to make an interesting claim about the source
of jetting for active galactic nuclei (AGN)...

MIT happens to be Evans' hosting institution.

http://web.mit.edu/newsoffice/2010/black-hole-jets.html

I'm highly interested in reading the full scholarly article
but this looks like rather speculative guessing to me. I
might go down to UW just for this.


Let us know what you find. Your shoes need to trod that ground again
anyway...


Walking to UW to borrow their institutional access to ApJ, MNRAS, Phys. Rev.
D, Science, Nature, etc is a part of my weekly ritual.

The Feb. 10 issue of ApJ was already trawled over by me, and I still have a
bunch of articles I downloaded last week that I have not yet read. But the
Evans article is not in that pile, because the blurb on the ApJ site (which
mirrors what they put on print) is not interesting.

ApJ in print form, for an entire month, is roughly 4 inches thick give or
take. The index, double sided, is six pages with a one sentence blurb about
the research. This is something people do not realize.

The observations are based on surveys by X-ray telescopes (Suzaku, XMM-
Newton, Chandra, Swift). This tells you immediately that there are no direct
observations of the region in question like how VLBI imagery directly
surveyed the area around Sgr. A*. There is nothing suspect about the
observations, as far as I can tell. Though I note with perpetual amusement
that there have to be corrections to events recorded by the satellites as
they pass through the South Atlantic Anomaly.

Speculation that there is no inner reflective surface is based on the non-
observation of the Iron-alpha emission lines. For reference, the two lines
are a 6.404 and 6.391 (from my notes..) doublet that show up rather

^^^^^^^^^^^^^^^^^^^^

Maybe it should be obvious, but ... eV, keV, Angstrom?

--John Park

prominently and have been used for a very long time as a strong diagnostic
of 'what is going on' in accretion regions. Given that the AGN is only at z
=~0.03, there's an expectation of Iron being present.

Though the methodology that says there is no reflection, while not 'wrong',
is certainly up for debate.

Simple fitting of what the telescopes observe are consistent with a power
law spectrum that has some absorbing properties. No big surprise there -
power law spectrae are par for the course when it comes to astrophysics, and
absorbing of light is not a shocker when it comes to ionized locales.

What a straight reading of this one piece of scholarly research does not
indicate is that there is a super, super, SUPER strong coupling between the
inclination angle of the accretion disk and what is observed on Earth.
Furthermore, even a reasonable fit on the angle is ****ing hard to make even
for close and cooperative regions in which a wide variety of wavelengths are
available. So when Evans assumes a 60 degree angle for the inclination,
without sourcing it, it raises an eyebrow.

Also, Evans uses a simulation called 'reflexionx' for modeling the X-ray
spectrum. That raises another eyebrow because in "Measuring the spin of
GRS1915+105 with relativistic disk reflection"; J. Blum et.al., ApJ 706 p60
(the subject should tell you this ties in), it was found that the reflexionx
model was giving results for the spin parameter that were inconsistent with
previous works on the subject using equivalent data sets. So I'll smack
anyone who makes a serious argument using this paper's interpretations of
the data unless some very fancy footwork is done.

This tells you everything you need to know:

"Our results demonstrate that 3C 33 shows no signs of Compton
reflection from neutral material in the inner regions of an
accretion disk: there is no reflection hump at energies 10 keV,
and no evidence for relativistically broadened Fe K? emission
(Model VII)."

I fully expect that the inner part of accretion flow is mostly plasma, and I
thought that before it was later pointed out that all the data is consistent
with an ionized accretion flow.

The thing that I really, really wanted to see was a substantiation of the
claim that retrograde accretion flow with respect to the spin of the black
hole could *happen*, and explain what's seen.

"The X-ray spectrum of 3C 33 is also consistent with the picture
of Garofalo et al. (2009). They argue the jet power of high-
excitation radio galaxies such as 3C 33 is the result of
retrograde black-hole spin with respect to the accreting material.
This configuration results in a larger innermost circular stable
orbit than for a prograde black hole. The weak or absent
signatures of reflection in 3C 33, then, are simply a consequence
of the large inner disk radius."

My opinion on this has not changed. At all. I do not see how it is
physically possible, much less plausible.

Furthermore, the direction in which a Kerr black hole rotates has an
abundance of ****-all to do with the radius of the innermost stable orbit
for massive particles. So it is my very, very strong personal opinion that
the claim that a black hole spinning in one direction versus another
direction has anything to do with the location of the innermost stable
circular orbit.

I really, REALLY wanted to read Garofalo (2009), but it doesn't exist. I'm
substantially irritated that the only substantiation of the theory was a one
paragraph blurb that references an article that doesn't exist yet.

"Garofalo, D., Evans, D. A., & Sambruna, R. M. 2009, MNRAS,
submitted"

That Evans is second author on that reference makes me wonder ever so
slightly. Especially since not once in my ever-larger reading on this
subject have I ever seen the idea that retrograde accretion flow can exist,
much less do what is claimed.

I've made a note in my notebook on this, and I'll keep a lookout for the
article in MNRAS but I'm highly skeptical at this point.

People sometimes wonder how the time I spend on this newsgroup manifests
itself. This oughta clear that up.


David A. Smith




  #10  
Old February 13th 10, 12:56 AM posted to sci.physics,sci.astro
john
external usenet poster
 
Posts: 112
Default Active galaxy jets may be due to blackholes spinning backwardsfrom their accretion disks

On Feb 12, 8:30*am, dlzc wrote:
Dear john:

On Feb 11, 8:07*pm, john wrote:

On Feb 11, 2:11*pm, dlzc wrote:

...
If we have charged particle separation then we'd
require a charged central hole as well, it would
seem. *Our own central black hole is spawning
antiparticles from one pole too. *Wonder how that
works? *How do you polarize antiparticle creation...


How many antiparticles?


My assumption was one charge out one pole,
the other out the other.


This says no antimatter:http://www.physorg.com/news79361214.html

These say antimatter:http://adsabs.harvard.edu/abs/2002co...lky-way-galaxy

The signature of matter / antimatter annihilations is seen on only one
jet.

David A. Smith


cool- thx
john
 




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