David Bernier wrote:
wrote:
I need some distance measure because I can see the Great Wall
then Great Attractor then Shapley Concentrate then Sloan Great
Wall are all in the same direction. So I need some distance measure.

--- quoting somemore of Wikipedia to get some distance gauge ---
Location

The first indications of a deviation from uniform expansion of the
universe were reported in 1973 and again in 1978. The location of the
Great Attractor was finally determined in 1986, and is situated at a
distance of somewhere between 150 and 250 Mly (47-79Mpc) (the latter
being the most recent estimate) from the Milky Way, in the direction
of the Hydra and Centaurus constellations. While objects in that
direction lie in the zone of avoidance (the part of the night sky
obscured by the Milky Way galaxy) and are thus difficult to study with
visible wavelengths, X-ray observations have revealed that the region
of space is dominated by the Norma cluster (ACO 3627),[1][2] a massive
cluster of galaxies, containing a preponderance of large, old
galaxies, many of which are colliding with their neighbours, and/or
radiating large amounts of radio waves.


The Shapley Supercluster (Shapley Concentration) is the largest
concentration of galaxies in our nearby Universe that forms a
gravitationally interacting unit, thereby pulling itself together
instead of expanding with the Universe. It appears as a striking
overdensity in the distribution of galaxies in the constellation of
Centaurus, approximately 650 million light years from the Milky Way.
--- end quoting ---

So here is the distance measu

(1) Great Wall at 200 million light years from Earth

(2) Great Attractor at 250 million light years from Earth

(3) Shapley Concentrate at 650 million light years from Earth

(4) Sloan Great Wall at 1,000 million light years from Earth

You might like the movie "Flight to the Virgo Cluster"
presented by B. Tully of the University of Hawaii.

Cf.:
http://www.ifa.hawaii.edu/~tully/outreach/movie.html

David Bernier




Thanks, a good show!!