Arp and Quasar-Galaxy alignments proposed statistical study

In article ,
Ray Tomes wrote:
Yes, of course there will be some. This can be calculated statistically
how many will fall within what distance. However I suggested the Monte
Carlo approach which is to compare to random datasets or moire simply
the same dataset rotated in space. If for 100 random rotations the
average associations within some range were say 40 with a maximum of 90
and the actual data had 250 associations then it would be very
convincing but if it were 85 then it would not.

Some test along these lines would certainly be one way to proceed.

However the really fascinating thing in Arp's data are the matched pairs
of quasars at similar redshifts (not identical and too far apart -
both proving it is not gravitational lensing) along opposite sides of
the axis of large nearby spirals.

Bear in mind that you expect to see (comparatively) widely separated
structures with similar redshifts in the standard model of big bang
structure formation. The question, again, is whether there's a
statistically significant excess of these associated with nearby
galaxies.

The Arp proposal does explain the very wide scatter in redshift versus
brightness of quasars compared to galaxies - because only part of the
redshift is considered to be cosmological. I don't think big bang
cosmology can explain this wide scatter.

Big bang cosmology doesn't need to -- this is just AGN physics. There
is a large scatter in the luminosities of AGN such as Seyferts and
low-luminosity radio galaxies at zero redshift, where presumably even
Arp doesn't think any new physics is happening. In the standard
picture, AGN luminosity is controlled by the black hole mass and
accretion rate, and it's entirely plausible that these differ widely
for different quasars at similar redshifts (in particular the
accretion rate depends on the very small scale environment of the
central black hole).

Martin
--
Martin Hardcastle Department of Physics, University of Bristol
A little learning is a dangerous thing; / Drink deep, or taste not the
Pierian spring; / There shallow draughts intoxicate the brain ...

"PH" == Phillip Helbig writes:

PH In article , Ray Tomes
PH writes:

dropping to values nearer the galaxy redshift at greater
distance. Arp interprets this as the quasars having been ejected
from the spiral galaxy along the axis in the matched pairs at
various time intervals.

PH I once did a back-of-the-envelope calculation that if QSOs were
PH really ejected from M33 as Arp claims, then one should be able to
PH DETECT THEIR PROPER MOTION WITH VLBI. To my knowledge, no-one has
PH tried this. This would falsify his theory of ejection.

As you note elsewhere, it might be difficult to get observing time to
try this. *However*, one could try something similar. The defining
reference frame for astronomy is based on VLBI observations of
quasars. One could see what limits there are on quasar proper motions
from the various measurements used to define and maintain the
International Celestial Reference Frame.

I don't know what those limits would be, but my guess is that they
would be fairly stringent. For instance, the source 4C 39.25 was
observed to be "moving around" relative to other sources. This source
is well known to have changes in its structure. The changes in the
source structure (as various parts of the source became slightly
brighter or dimmer) was enough to account for the source's apparent
motion.

In the course of looking at 4C 39.25, the authors also looked at other
quasars and found that they were essentially not moving at levels of a
few tens of *microarcseconds* per year.

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"PH" == Phillip Helbig writes:

PH In article , Ray Tomes
PH writes:

dropping to values nearer the galaxy redshift at greater
distance. Arp interprets this as the quasars having been ejected
from the spiral galaxy along the axis in the matched pairs at
various time intervals.

PH I once did a back-of-the-envelope calculation that if QSOs were
PH really ejected from M33 as Arp claims, then one should be able to
PH DETECT THEIR PROPER MOTION WITH VLBI. To my knowledge, no-one has
PH tried this. This would falsify his theory of ejection.

As you note elsewhere, it might be difficult to get observing time to
try this. *However*, one could try something similar. The defining
reference frame for astronomy is based on VLBI observations of
quasars. One could see what limits there are on quasar proper motions
from the various measurements used to define and maintain the
International Celestial Reference Frame.

I don't know what those limits would be, but my guess is that they
would be fairly stringent. For instance, the source 4C 39.25 was
observed to be "moving around" relative to other sources. This source
is well known to have changes in its structure. The changes in the
source structure (as various parts of the source became slightly
brighter or dimmer) was enough to account for the source's apparent
motion.

In the course of looking at 4C 39.25, the authors also looked at other
quasars and found that they were essentially not moving at levels of a
few tens of *microarcseconds* per year.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

Joseph Lazio wrote:
As you note elsewhere, it might be difficult to get observing time to
try this. *However*, one could try something similar. The defining
reference frame for astronomy is based on VLBI observations of
quasars. One could see what limits there are on quasar proper motions
from the various measurements used to define and maintain the
International Celestial Reference Frame.

I don't know what those limits would be, but my guess is that they
would be fairly stringent. For instance, the source 4C 39.25 was
observed to be "moving around" relative to other sources. This source
is well known to have changes in its structure. The changes in the
source structure (as various parts of the source became slightly
brighter or dimmer) was enough to account for the source's apparent
motion.

In the course of looking at 4C 39.25, the authors also looked at other
quasars and found that they were essentially not moving at levels of a
few tens of *microarcseconds* per year.

That is some very accurate measuring.

Previously I wrote:
At M33 distance a velocity of 0.01c gives 0.001" or arc movement per
year which would be detectable in a reasonable period of time. I assume
that the velocity would need to be of the order of 0.003c to 0.01c to
ensure escape from the galaxy.

OK, we can get a test of Arp's hypothesis that quasars are ejected from
galaxies. Let us take the most favourable values for Arp and if things
don't fit he must be wrong.

The minimum velocity of ejection of a quasar would need to be 0.002c+ to
get free of the gravity of a spiral galaxy with typical rotation rate of
almost 0.001c.

At M33 distance this would translate to a minimum of 0.0002" per year.
So taking your "few tens of microarcseconds" to be 0.00003" per year
then the motion should be detectable right now for any quasars within
about 7 times M33 distance. According to Arp, quite a few quasars are
associated with galaxies within that range, so a real test is possible.

The fact that one source is moving (out of how many measured I do not
know?) is a possible argument in favour of Arp, but there would need to
be more in the moving category for sure.

What is the red shift of 4C 39.25, and what does its motion translate to
in terms of velocity if the red shift is comsological? If its red shift
is more than about 0.1 then the velocity will likely be greater than c?
Big Bang cosmology has to withstand this test.

I know that there have been reports of superluminal velocities in
quasars (or parts of them) and that these are accounted for by the
geometry of the situation. Is the same argument being used here?
Statistically, we would expect the required geometrical configuration
(of parts moving almost exactly towards us) to arise in a small
proportion of cases.

Ray Tomes

Joseph Lazio wrote:
As you note elsewhere, it might be difficult to get observing time to
try this. *However*, one could try something similar. The defining
reference frame for astronomy is based on VLBI observations of
quasars. One could see what limits there are on quasar proper motions
from the various measurements used to define and maintain the
International Celestial Reference Frame.

I don't know what those limits would be, but my guess is that they
would be fairly stringent. For instance, the source 4C 39.25 was
observed to be "moving around" relative to other sources. This source
is well known to have changes in its structure. The changes in the
source structure (as various parts of the source became slightly
brighter or dimmer) was enough to account for the source's apparent
motion.

In the course of looking at 4C 39.25, the authors also looked at other
quasars and found that they were essentially not moving at levels of a
few tens of *microarcseconds* per year.

That is some very accurate measuring.

Previously I wrote:
At M33 distance a velocity of 0.01c gives 0.001" or arc movement per
year which would be detectable in a reasonable period of time. I assume
that the velocity would need to be of the order of 0.003c to 0.01c to
ensure escape from the galaxy.

OK, we can get a test of Arp's hypothesis that quasars are ejected from
galaxies. Let us take the most favourable values for Arp and if things
don't fit he must be wrong.

The minimum velocity of ejection of a quasar would need to be 0.002c+ to
get free of the gravity of a spiral galaxy with typical rotation rate of
almost 0.001c.

At M33 distance this would translate to a minimum of 0.0002" per year.
So taking your "few tens of microarcseconds" to be 0.00003" per year
then the motion should be detectable right now for any quasars within
about 7 times M33 distance. According to Arp, quite a few quasars are
associated with galaxies within that range, so a real test is possible.

The fact that one source is moving (out of how many measured I do not
know?) is a possible argument in favour of Arp, but there would need to
be more in the moving category for sure.

What is the red shift of 4C 39.25, and what does its motion translate to
in terms of velocity if the red shift is comsological? If its red shift
is more than about 0.1 then the velocity will likely be greater than c?
Big Bang cosmology has to withstand this test.

I know that there have been reports of superluminal velocities in
quasars (or parts of them) and that these are accounted for by the
geometry of the situation. Is the same argument being used here?
Statistically, we would expect the required geometrical configuration
(of parts moving almost exactly towards us) to arise in a small
proportion of cases.

Ray Tomes

On Sun, 24 Aug 2003 17:12:33 GMT, Ray Tomes
wrote:
Can you advise me on suitable catalogues for both quasars and galaxies
to use in such a test? I guess that the galaxies is simple enough
because we only need the nearby bright spirals. For quasars, the
catalogues that I have seen are not representative of the whole sky. The
catalogue should represent some are of sky to some limiting magnitude.
That area of sky should hold some nearby spirals and ideally some spaces
without them also.

Someone please help me to use data that would be acceptable to
astronomers / cosmologists in being suitable for such a test and telling
me a URL where I can download those catalogues from.

For completeness you could try the recently-published SDSS first
release. Both galaxy and quasar catalogues are available for the same
strips of sky. Go to
http://www.sdss.org/dr1/products/spe...etspectra.html for links to
the 4 redshift catalogues.

Similarly, for different strips of sky you could combine the 2dF
galaxies at http://www.mso.anu.edu.au/2dFGRS with the 2dF quasars at
http://www.2dfquasar.org/Spec_Cat/catalogue.html

Eric

On Sun, 24 Aug 2003 17:12:33 GMT, Ray Tomes
wrote:
Can you advise me on suitable catalogues for both quasars and galaxies
to use in such a test? I guess that the galaxies is simple enough
because we only need the nearby bright spirals. For quasars, the
catalogues that I have seen are not representative of the whole sky. The
catalogue should represent some are of sky to some limiting magnitude.
That area of sky should hold some nearby spirals and ideally some spaces
without them also.

Someone please help me to use data that would be acceptable to
astronomers / cosmologists in being suitable for such a test and telling
me a URL where I can download those catalogues from.

For completeness you could try the recently-published SDSS first
release. Both galaxy and quasar catalogues are available for the same
strips of sky. Go to
http://www.sdss.org/dr1/products/spe...etspectra.html for links to
the 4 redshift catalogues.

Similarly, for different strips of sky you could combine the 2dF
galaxies at http://www.mso.anu.edu.au/2dFGRS with the 2dF quasars at
http://www.2dfquasar.org/Spec_Cat/catalogue.html

Eric

In article ,
Ray Tomes wrote:
The fact that one source is moving (out of how many measured I do not
know?) is a possible argument in favour of Arp, but there would need to
be more in the moving category for sure.

If, as Joseph says, the apparent motion can be entirely explained in
terms of changes in structure (e.g. one component gets fainter and one
gets brighter, so the apparent mean position moves) then this isn't an
argument in favour of Arp's position.

I know that there have been reports of superluminal velocities in
quasars (or parts of them) and that these are accounted for by the
geometry of the situation. Is the same argument being used here?
Statistically, we would expect the required geometrical configuration
(of parts moving almost exactly towards us) to arise in a small
proportion of cases.

You need to be careful in making this claim, because in the standard
model the high speed and alignment towards us also give rise to
Doppler boosting (SR effect leading to greater observed brightness).
So in a flux-limited sample of radio sources you will have more
aligned objects than you `should' have if the angles were completely
randomly distributed wrt the line of sight. This also leads to the
problem that the sources at large angles to the line of sight are too
faint (Doppler suppression) to allow component speeds to be measured
with VLBI.

Martin
--
Martin Hardcastle Department of Physics, University of Bristol
A little learning is a dangerous thing; / Drink deep, or taste not the
Pierian spring; / There shallow draughts intoxicate the brain ...

In article ,
Ray Tomes wrote:
The fact that one source is moving (out of how many measured I do not
know?) is a possible argument in favour of Arp, but there would need to
be more in the moving category for sure.

If, as Joseph says, the apparent motion can be entirely explained in
terms of changes in structure (e.g. one component gets fainter and one
gets brighter, so the apparent mean position moves) then this isn't an
argument in favour of Arp's position.

I know that there have been reports of superluminal velocities in
quasars (or parts of them) and that these are accounted for by the
geometry of the situation. Is the same argument being used here?
Statistically, we would expect the required geometrical configuration
(of parts moving almost exactly towards us) to arise in a small
proportion of cases.

You need to be careful in making this claim, because in the standard
model the high speed and alignment towards us also give rise to
Doppler boosting (SR effect leading to greater observed brightness).
So in a flux-limited sample of radio sources you will have more
aligned objects than you `should' have if the angles were completely
randomly distributed wrt the line of sight. This also leads to the
problem that the sources at large angles to the line of sight are too
faint (Doppler suppression) to allow component speeds to be measured
with VLBI.

Martin
--
Martin Hardcastle Department of Physics, University of Bristol
A little learning is a dangerous thing; / Drink deep, or taste not the
Pierian spring; / There shallow draughts intoxicate the brain ...

Morgoth wrote:
0.698 [1], which with a very rough back-of-the-envelope and horrendous
guestimate calculation, assuming a value of the deceleration parameter
of between 0 and -0.6 [2], works out at about 3-4000 Mpc.

I calculate this as 10*c which needs some explaining. OK, here it comes ...

Martin Hardcastle wrote:
If, as Joseph says, the apparent motion can be entirely explained in
terms of changes in structure (e.g. one component gets fainter and one
gets brighter, so the apparent mean position moves) then this isn't an
argument in favour of Arp's position.

However this sort of high rate of motion has to be considered more
easily consistent with Arp's view than with redshift being 100%
cosmological. While one object aiming right at us is possible, if too
many such objects are found then we start to look like a special place
in the universe.

You need to be careful in making this claim, because in the standard
model the high speed and alignment towards us also give rise to
Doppler boosting (SR effect leading to greater observed brightness).
So in a flux-limited sample of radio sources you will have more
aligned objects than you `should' have if the angles were completely
randomly distributed wrt the line of sight. This also leads to the
problem that the sources at large angles to the line of sight are too
faint (Doppler suppression) to allow component speeds to be measured
with VLBI.

Certainly. However there are other things that must also be the case if
this is a correct explanation. When plotted on a redshift-brightness
diagram the object should be correspondingly very high up due to this
enhanced brightness. Is this the case?

Ray Tomes