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Shapley SuperCluster
Posted: Sat Jan 12, 2013 1:26 pm
by ErnieM
I stumbled on this link:
http://www.solstation.com/x-objects/greatatt.htm which says
In late 2005, a team of astronomers engaged in a X-ray survey called the Clusters in the Zone of Avoidance (CIZA) project revealed that the Milky Way is not being drawn towards a concentration of mass called the Great Attractor but to an even more massive region behind it called the Shapley Supercluster, which lies around 500 million light-years away or four times the distance to the Great Attractor. Over the two decades since the discovery of the Great Attractor, subsequent observations at infrared wavelengths indicated that the Milky Way not, in fact, bring drawn towards the Great Attractor. Indeed, the CIZA team reported that the Great Attractor actually has only about a tenth the mass that was originally estimated
From this article
http://www.atlasoftheuniverse.com/superc/shapley.html , there is a picture of our Milky Way relative to the Shapley Supercluster
http://www.atlasoftheuniverse.com/superc/shapleymap.gif .
Is this an indication of an isolated case of the force of gravity winning over dark energy and the expansion of space?
Re: Shapley SuperCluster
Posted: Sat Jan 12, 2013 2:53 pm
by neufer
Gravity vs Dark Energy
Posted: Sat Jan 12, 2013 6:11 pm
by ErnieM
from
http://www.atlasoftheuniverse.com/superc/shapley.html
This map (which looks down onto the supergalactic plane) shows all of the major clusters of galaxies between us and the Shapley supercluster. Our Galaxy is located at the lower-left, and between us and the Shapley supercluster lies the Centaurus supercluster. At a distance of 650 million light years, the Shapley supercluster is a dense collection of approximately 20 major clusters of galaxies contained within a region that is not much larger than the Virgo supercluster (which only contains one major cluster).
In the middle of the Shapley supercluster are several massive clusters. The Abell catalogue contains only five clusters of galaxies with a richness class above 2 within one billion light years from us. Three of these clusters (A3558, A3559 and A3560) are in the Shapley supercluster. The fourth cluster (A3128) is in the Horologium supercluster, and the fifth cluster (A3301) is on the edge of the Horologium supercluster. These clusters are some of the richest clusters of galaxies known and some of them contain more galaxies than the very rich Coma cluster.
Within local galaxy clusters, member galaxies collide and merge due to gravitaty. Our Milky Way is in the Virgo Cluster and the whole cluster is being pulled in towards the Shapley SuperCluster. I imagine the same is happening to the Coma and Centaurus Superclusters.
if these are proven to be true, then dark energy may not be as pervasive in this region of the universe. And the view of the night may not be as cold and lonely in the far future. In fact, I imagine it may be quite the opposite. Spectacular and majestic.
Gravity vs. Dark Matter
Posted: Sat Jan 12, 2013 6:59 pm
by ErnieM
With all due respect, does any of the red shift galaxies observed to be moving away from us belong to the galaxy superclusters in this map?
If none, then these prior observed red shift galaxies may be being pulled in towards their respective still to be discovered galaxy superclusters. If this is the case, dark energy may not be needed to explain observed galactic movements. The universe may not be expanding after all. As the collective mass of the merging galaxy clusters grow, so do the space curvature of the resulting "ultraClusters". Hopefully, the James Webb telescope and the next generations of instruments provide the answers.
Re: Gravity vs Dark Energy
Posted: Sat Jan 12, 2013 9:50 pm
by neufer
ErnieM wrote:
Within local galaxy clusters, member galaxies collide and merge due to gravitation. Our Milky Way is in the Virgo Cluster and the whole cluster is being pulled in towards the Shapley SuperCluster. I imagine the same is happening to the Coma and Centaurus Superclusters.
if these are proven to be true, then dark energy may not be as pervasive in this region of the universe. And the view of the night may not be as cold and lonely in the far future. In fact, I imagine it may be quite the opposite. Spectacular and majestic.
In essence: the Local Group, Coma & Centaurus Superclusters are all falling (at
~0.002 c) in the general direction of
where the Shapley SuperCluster USED TO BE (i.e., RA: 11h 7m Dec.: -27° 20') billions of years ago when it was
much much closer.
The Shapley SuperCluster
has since left the arena and is currently receding at
~.044 c in the direction (
RA: 13h 25m Dec.: -30° 0′ 0″). With dark energy accelerating that expansion we have no hope of catching up with it.
Re: Shapley SuperCluster
Posted: Sun Jan 13, 2013 2:46 am
by ErnieM
Ernie wrote:
With all due respect, does any of the red shift galaxies observed to be moving away from us belong to the galaxy superclusters in this map?
If none, then these prior observed red shift galaxies may be being pulled in towards their respective still to be discovered galaxy superclusters. If this is the case, dark energy may not be needed to explain observed galactic movements. The universe may not be expanding after all. As the collective mass of the merging galaxy clusters grow, so do the space curvature of the resulting "ultraClusters". Hopefully, the James Webb telescope and the next generations of instruments provide the answers.
Neufer wrote:
The Shapley SuperCluster has since left the arena and is currently receding at ~.044 c in the direction (RA: 13h 25m Dec.: -30° 0′ 0″). With dark energy accelerating that expansion we have no hope of catching up with it.
Thank you Neufer. My apologies. The information I was asking is contained in the same link but my wild imagination got the better of me. Here is the table from the article listing the galaxy resshift numbers.
1 2 3 4 5 6 7
Abell Equatorial Redshift Distance Rich Notes
Number Coordinates z Mly
RA Dec
A1631 12 52.8 -15 26 .0450 615 0
A1644 12 57.2 -17 21 .0461 630 1
A3528 12 54.3 -29 01 .0516 700 1
A3530 12 55.6 -30 21 .0525 715 0
A3532 12 57.3 -30 22 .0542 735 0
A3537 13 01.0 -32 26 .0308 425 0 foreground cluster
A3542 13 08.7 -34 34 .0513 700 0
A1709 13 18.7 -21 28 .0509 695 0
A3553 13 19.2 -37 11 .0475 650 0
A3554 13 19.5 -33 29 .0458 625 1
A3555 13 20.8 -28 59 .0476 650 1
A3556 13 24.1 -31 40 .0467 635 0
A1736 13 26.9 -27 07 .0446 610 0
A3558 13 27.9 -31 30 .0468 640 4 'Shapley 8'
A3559 13 29.9 -29 31 .0449 615 3
A3560 13 31.8 -33 13 .0477 650 3
A3562 13 33.5 -31 40 .0478 650 2
A3564 13 34.4 -35 13 .0493 670 1
A3566 13 39.0 -35 33 .0498 680 2
A3570 13 46.8 -37 55 .0354 485 0
A3571 13 47.5 -32 52 .0379 520 2
A3572 13 48.2 -33 23 .0505 690 0
A3575 13 52.6 -32 53 .0365 500 0
A3577 13 54.3 -27 51 .0482 655 2
A3578 13 57.5 -24 44 .0381 520 1
So it is going to be a dark and lonely "island universe" in the very distant future.
Nahh it's not shapely
Posted: Fri Jan 18, 2013 9:48 am
by ritwik
The universe is not only expanding — it's being swept along in the direction of constellations Centaurus and Hydra at a steady clip of one million miles per hour, pulled, perhaps, by the gravity of another universe.
Scientists have no idea what's tugging at the known world, except to say that whatever it is likely dates back to the fraction of the second between the universe's explosive birth 13.7 billion years ago and its inflation a split second later.
"At this point we don't have enough information to see what it is, or to constrain it. We can only say with certainty that somewhere very far away the world is very different than what we see locally. Whether it's 'another universe' or a different fabric of space-time we don't know," Alexander Kashlinsky at NASA's Goddard Space Flight Center in Greenbelt, Maryland, told Discovery News.
"It's the same flow at a distance of a hundred million light-years as it is at 2.5 billion light-years and it points in the same direction and the same amplitude. It looks like the entire matter of the universe is moving from one direction to the next," Kashlinsky said.
"If our universe is all that's there, then the liquid in the box shouldn't be sliding. Whatever is pulling it has to be bigger than the size of the box," she said. "There is a structure beyond the horizon of our universe and that structure is exerting a force on our universe and creating this flow."
http://news.discovery.com/space/history ... iverse.htm
Dark Flow: coming or going?
Posted: Fri Jan 18, 2013 2:32 pm
by neufer
http://en.wikipedia.org/wiki/Dark_flow wrote:
<<Dark flow is an astrophysical term describing a possible non-random component of the peculiar velocity of galaxy clusters. The actual measured velocity is the sum of the velocity predicted by Hubble's Law plus a small and unexplained (or dark) velocity flowing in a common direction.
Analyzing the three-year Wilkinson Microwave Anisotropy Probe (WMAP) data using the kinematic
Sunyaev-Zel'dovich effect, the authors of the study found evidence of a "surprisingly coherent" 600–1000 km/s flow of clusters toward a 20-degree patch of sky between the constellations of Centaurus and Vela.
The authors, Alexander Kashlinsky, F. Atrio-Barandela, D. Kocevski and H. Ebeling, suggest that the motion may be a remnant of the influence of no-longer-visible regions of the universe prior to inflation. Telescopes cannot see events earlier than about 380,000 years after the Big Bang, when the universe became transparent (the Cosmic Microwave Background); this corresponds to the particle horizon at a distance of about 46 billion light years. Since the matter causing the net motion in this proposal is outside this range, it would in a certain sense be outside our visible universe; however, it would still be in our past light cone. The results appeared in the October 20, 2008, issue of Astrophysical Journal Letters. Since then, the authors have extended their analysis to additional clusters and the recently released WMAP five-year data.
The dark flow was determined to be flowing in the direction of the Centaurus and Hydra constellations. This corresponds with the direction of the Great Attractor, which is a gravitational mystery originally discovered in 1973. However, the source of the Great Attractor's attraction was thought to originate from a massive cluster of galaxies called the Norma Cluster, located about 250 million light-years away from the Milky Way.
In a study from March 2010, Kashlinsky extended his work from 2008, by using the 5-year WMAP results rather than the 3-year results, and doubling the number of galaxy clusters observed from 700. The team also sorted the cluster catalog into four "slices" representing different distance ranges. They then examined the preferred flow direction for the clusters within each slice. While the size and exact position of this direction display some variation, the overall trends among the slices exhibit remarkable agreement. "
We detect motion along this axis, but right now our data cannot state as strongly as we'd like whether the clusters are coming or going," Kashlinsky said. The team has so far catalogued the effect as far out as 2.5 billion light-years, and hopes to expand its catalog out further still to twice the current distance.
Criticisms: Astrophysicist Ned Wright posted an online response to the study arguing that its methods are flawed. The authors of the "dark flow" study released a statement in return, refuting three of Wright's five arguments and identifying the remaining two as a typo and a technicality that do not affect the measurements and their interpretation. A more recent statistical work done by Ryan Keisler claims to rule out the possibility that the dark flow is a physical phenomenon because Kashlinsky et al. do not consider primary CMB anisotropies as important as they are. The existence and the velocity of dark flow will probably stay disputed until the new accurate cosmic microwave background radiation data by the European Space Agency's Planck satellite are available in 2012.>>