Parallax vs Redshift distance comparisons

There is nothing reliable on that page. It includes many misleading
statement and several downright falshoods. Find a more reputable source.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools Software for the Observer:
http://www.skyhound.com/cs.html

Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html

To reply remove spleen

Wasn't it Abdul Ahad who wrote:
Greg Crinklaw wrote in message news:101da283j7eg7
...
Abdul Ahad wrote:
Hubble's law and the validity of redshift for distance assumptions
seems to break down completely when it comes to Quasars.

That's not a true statement. Arp's work has been largely discredited
based on statistical bias and other huge flaws in the methodology.


The chart at the bottom of this page:
http://www.geocities.com/newastronomy/quasars.htm

shows that quasars fall way outside the line of best-fit. The way I
understand it, Hubble's law stipulates that if you plot the redshift
of galaxies (or their recession velocity) against their distances
(visual brightness) then one should get a broadly straight-line
relationship.

It appears that this does not hold true for quasars, causing some
astronomers to suspect that quasars may be nearer than we think?
There are also independent cases I have read in a book called "Seven
wonders of the universe" where it *appears* that quasars seemingly
*gravitationally associated* with a galaxy have much larger redshifts
than the galaxy itself!

We can't observe Cepheid Variables or Type 1a Supernovae in quasars. We
don't have any way to estimate the intrinsic brightness of a quasar. We
can't use parallax or main sequence fitting or any distance measure
except using their redshift and Hubble's Law.

The page you quote seems to attempt to estimate the distance to a quasar
by looking at the brightness of galaxies that are nearly in the same
line of sight. If that leads to results that disagree with Hubble's Law,
then it's probably Hubble that is correct.

Recent theories about quasars suggest that they might be the cores of
active galaxies that just happen to have their jets oriented towards us.
Active galaxies at that distance that have jets oriented in other
directions are not visible to us. If that is the case, then it's
possible that the redshifts we observe are blue shifted by the real
motion of material in the jet. This would suggest that the quasars could
be much further away than the observed redshifts suggest rather than
closer as suggested on that web page.

--
Mike Williams
Gentleman of Leisure

(Abdul Ahad) wrote in message . com...

The chart at the bottom of this page:
http://www.geocities.com/newastronomy/quasars.htm

shows that quasars fall way outside the line of best-fit. The way I
understand it, Hubble's law stipulates that if you plot the redshift
of galaxies (or their recession velocity) against their distances
(visual brightness) then one should get a broadly straight-line
relationship.

The chart shows that Quasars are brighter than galaxies, nothing
else! This falls into the "well DUH" catagory. Notice that the
axes are labled aparent magnitude and redshift, while the conventional
use of the Hubble law indicates a relationship between distance and
redshift. We can "see" quasars because they are bright, in reality,
though, we can see then a generation earlier than we get large
enough telescopes that can image their surroundings, nothing more.

(Mitch Alsup) wrote in message . com...
(Abdul Ahad) wrote in message . com...

The chart at the bottom of this page:
http://www.geocities.com/newastronomy/quasars.htm

shows that quasars fall way outside the line of best-fit. The way I
understand it, Hubble's law stipulates that if you plot the redshift
of galaxies (or their recession velocity) against their distances
(visual brightness) then one should get a broadly straight-line
relationship.

The chart shows that Quasars are brighter than galaxies, nothing
else! This falls into the "well DUH" catagory. Notice that the
axes are labled aparent magnitude and redshift, while the conventional
use of the Hubble law indicates a relationship between distance and
redshift.

I think the intention in this chart is to say that apparent
*brightness* (magnitude) is supposed to correspond to actual
*luminosity* (light output). Example: if a galaxy is of 15th magnitude
in appearence, then by Hubble's law we expect it to have a redshift of
X. If a quasar is of 15th magnitude and it has a greater redshift of
say X times 3 ...the implication is either the quasar is immensely
super-luminous compared to the galaxy and it lies at the further
redshift-predicted distance of three times that of the galaxy - or it
is in fact much closer to us than inferred by its redshift, hence it
looks visually brighter and therefore defies Hubble's law!

I don't put too much confidence in these charts as the source is not
credible. However in a book called "Seven wonders of the Cosmos" by
some professor named Jayant V. Narlikar, published by Cambridge
University Press 1999, on pages 307 through 311 reference is made to
H. C. Arp's peculiar findings.

In the first case, three quasars were found within small angular
distances of 73, 59, 73 seconds of arc from the galaxy NGC 3842. We
know quasars are relatively rare objects, sparsely scattered across
the sky. The odds of three quasars aligning around the galaxy by pure
chance is the same as getting 20 consecutive heads when tossing a coin
at random! Statistically speaking one would therefore be compelled to
say the three quasars *must* be associated with the galaxy! But how
can this be, when the galaxy has a redshift z=0.02, the 3 quasars have
z=0.34, 0.95 and 2.20!

In the second case, Narlikar quotes two triplets of 6 quasars - all 6
found on *one* of H. C. Arp's photographic plates. Each of the two
triplets of quasars were *perfectly* lined up on a straight line! The
odds of this happening by random chance are quoted as 4000 to 1 or
getting 12 heads straight after one another in a row, when randomly
tossing a coin!

The third case does not involve quasars but where two galaxies of
different redshifts seem to be connected by a thick filament! Quote
from the book: "The large galaxy [NGC 7603] has z=0.029 while the
small one...has z=0.057. If we assume the connection is real, then the
smaller galaxy has a relative radial velocity of about 8,300 km/s.
This is too high high to be explained as a random relative motion. So,
in order to keep Hubble's law alive...we have to assume that the two
galaxies *are not connected*, that the smaller galaxy happens to be
projected just at the end of the filament issuing from the big
galaxy!" /quote.

If the world's most prominent astronomers have dismissed Arp's
contra-Hubble findings on misrepresented facts or statistical errors,
then who am I to argue? Personally, I don't give that much credence to
these redshift anomalies but I thought I should share them anyway!

Abdul Ahad
http://uk.geocities.com/aa_spaceagen...eprojects.html
"We have lingered long enough on the shores of the cosmic ocean. We
are at last ready to set sail for the stars" - Carl Sagan.

One of these guys wrote:

In article ,
(Abdul Ahad) wrote:

(Mitch Alsup) wrote in message
. com...

(Abdul Ahad) wrote in message
. com...


[snip]

I don't put too much confidence in these charts as the source is not
credible. However in a book called "Seven wonders of the Cosmos" by
some professor named Jayant V. Narlikar, published by Cambridge
University Press 1999, on pages 307 through 311 reference is made to
H. C. Arp's peculiar findings.

Narlikar is a prominent anti-big-banger, in fact he and Padmanabhan
wrote "STANDARD COSMOLOGY and ALTERNATIVES: A Critcal Appraisal" for
the 2001 Annual Review of Astronomy and Astrophysics.

The basic question is whether apparent proximity on the sky means
proximity in space. The anti-BBs claim it must and advance various
statistical and visual ( tendrils, bridges, etc ) arguments to conclude
that, in this case, it does.

These arguments have failed to convince most cosmologists. The basic
counter-agument is that there are lots and lots of quasars and a few
close alignments are not unlikely. We have been burned too many times
to give "look-like" arguments much weight ( the canals on Mars are
just one example ).

A second counter argument is: If not due to do Hubble expansion
what is causing the red-shift? It can not be due to peculiar
velocity as all the Arp objects have higher red-shifts than the host.
( Nobody, not even Narlikar, beleives that they are preferentialy
moving away from Earth. ) It can not be gravitational red-shift as
the masses required would strongly distort the hosts.

The key is to find an independent measure of the distance. This
distance would use neither red-shift nor proximity. Two methods
are Type 1a SNe and Tully-Fisher, in a few cases where one of the
Arp objects is a spiral galaxy one or another of these methods have
been used to show that the galaxy is spatialy remote from the host.

Unfortunately quasars display neither SNe ( too far away ;-) )
nor rotating spiral arms. Figure out a method to measure the
distance and you will start getting invited to all the big-time
conferences.

Dark skies,

tom

PS Each of the two triplets of quasars were *perfectly* lined up
on a straight line! The odds of this happening by random chance
are quoted as 4000 to 1 ...

Since there are around a hundred thousand quasars your job
is to explain why there are so FEW of these alignments, at
4000-to-1 the expectation is about 25 per 100,000. I suspect
that if we look carefully many more alignments will be found
but that is a guess.

The third case does not involve quasars but where two galaxies of
different redshifts *seem* to be connected by a thick filament!

This is a look-like argument, see the canals of Mars for further
references. ( I added the stars around *seem*. )

--
We have discovered a therapy ( NOT a cure )
for the common cold. Play tuba for an hour.

Let's not forget that we have imaged "fuzz" around quasars. This fuzz
is the parent galaxy; something that was predicted by the current
interpretation of what a quasar is. Not only that, but there are a
range of qauasar-like objects going from classic point sources to
obvious galaxies that have bright active nuclei. Finally, we have a
theory that explains the energy source for the entire range of objects.
This argument was pretty much put to bed over a decade ago.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools Software for the Observer:
http://www.skyhound.com/cs.html

Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html

To reply remove spleen

Tom Kirke wrote:
The basic question is whether apparent proximity on the sky means
proximity in space. The anti-BBs claim it must and advance various
statistical and visual ( tendrils, bridges, etc ) arguments to conclude
that, in this case, it does.

These arguments have failed to convince most cosmologists. The basic
counter-agument is that there are lots and lots of quasars and a few
close alignments are not unlikely. We have been burned too many times
to give "look-like" arguments much weight ( the canals on Mars are
just one example ).

They have failed to convince most statistics people, too. With 100,000
quasars scattered about 40,000 odd square degrees (closer to 41,253, but
what's a few square degrees among friends?), the average concentration
is about 2.5 quasars per square degree. If we assume that the quasars
are Poisson, the probability that a second unrelated quasar will be
found within, say, 1 arcminute of a first one is merely 1 in 500. If
they aren't Poisson, that means that there is a bias to the distribution
and the probability of a chance alignment that close increases. (Are
the quasars far enough away that clustering can largely be ignored and
the Poisson distribution assumed? I don't know.)

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

jayant narlikar is one of the top 3 cosmologists in the world....he not a mere
prfessor, he is the director of the major indian astrophysics institute at
pune, india
he ranks with the top people in the us and uk.........and the indians have
long been the best astronomers and mathematicians in the world...i happen to
think narlikar and arp are completely right.....and niel turok also has huge
doubts about the current big bang position.....art swanson

arps work has not been discredited at all...some referees have slammed him but
other stat experts have said his stats are solid......and no one wants to talk
about his findings that redshifts are quantized...all experts run away from
this and dont even do decent analysis..they just dont want to know.....just
like catholic church vs galileo..disgusting...

Using the red shift to measure how far away stars are is not very
accureate for objects say 25 light years away. Using light from super
novas because their intensity seems to be close to the same is what is
best for long measure such as 12 billion LY out. Since photons wave
lengths stretch out over distance the longer the wave length the slower
its frequency,and that means we see redder red. Its in reality
measuring with a rubber band. Going further in that direction of
the spectrum goes to radio photons,and one might think the weaker the
signal the further the object(bad thinking). Best we can hope for is
the same weak radio signal we get nomatter what direction we point
Earth's radio telescopes recieves this same wave length radio wave. We
must be able to seperate our heat micro-wave signal (very important.)
Bert