Size and flows : As Douglas Adams rightly said, Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. Lets take an example. The Milky way is our galaxy. When talking about space, a galaxy is well understood. It's made of millions of stars. The size? Around 100,000 light years in diameter. If we had a spaceship going at exactly light speed (if that was possible), we would not even be able to cross one-thousandth of the distance in a hundred years.
Now Scientists have theorized about the size and movement of the local galactic supercluster. How have they been able to estimate its movement? By means of a simulation of the gravity and flow and density which pulls over 100,000 galaxies together into what is called the 'Great Attractor.' The human mind can possibly not even comprehend the size. The boundaries of this supercluster are not very well defined, and the flows are quite fascinating to watch. It takes me back to a post I made on flows (http://goo.gl/uho3rW) . At some stage, all the superclusters will be clumped into one. Maybe we will have a true idea of our Universe then!
+Knut Torgersen asked me to make this post... and here it is for your consumption. Though much has been said about the Laniakea Supercluster, this looks into the flows and size.
Cosmic Speed : The team used a database that compiles the velocities of thousands of galaxies, calculated after subtracting the average rate of cosmic expansion. “All these deviations are due to the gravitational pull galaxies feel around them, which comes from mass,” says Tully. The researchers used an algorithm to translate these velocities into a three-dimensional field of galaxy flow and density.
How did Brent Tully and his team do it? : If galaxies are clumped together closely in space they’ll orbit each other, or at least their mutual gravity will affect their motion. This in turn affects the redshift for each galaxy on top of the cosmic expansion. We know pretty well how the Universe is expanding on local scales, so if you subtract that part away, what’s left is the local motion of the galaxies. That can be used to map how gravity of other nearby galaxies is affecting them. This let them make a map of the density and movement of galaxies in space.
Size : The colossal supercluster is shown in the above computer-generated visualization, where green areas are rich with white-dot galaxies and white lines indicate motion towards the supercluster center. Galaxies flow into other galactic concentrations. The Laniakea Supercluster spans about 500 million light years and contains about 100,000 times the mass of our Milky Way Galaxy. The discoverers of Laniakea gave it a name that means "immense heaven" in Hawaiian.
Source Slate: http://www.slate.com/blogs/bad_astronomy/2014/09/04/laniakea_our_local_supercluster.html
Nature Source: http://www.nature.com/news/earth-s-new-address-solar-system-milky-way-laniakea-1.15819
Research paper: http://arxiv.org/abs/1409.0880
APOD source: http://apod.nasa.gov/apod/ap140910.html
Wikipedia reference: http://en.wikipedia.org/wiki/Laniakea_Supercluster
Video Link: Laniakea: Our home supercluster
Pics courtesy : http://goo.gl/Bsx20Q and http://goo.gl/y2MhAA
#laniakea #supercluster
Now Scientists have theorized about the size and movement of the local galactic supercluster. How have they been able to estimate its movement? By means of a simulation of the gravity and flow and density which pulls over 100,000 galaxies together into what is called the 'Great Attractor.' The human mind can possibly not even comprehend the size. The boundaries of this supercluster are not very well defined, and the flows are quite fascinating to watch. It takes me back to a post I made on flows (http://goo.gl/uho3rW) . At some stage, all the superclusters will be clumped into one. Maybe we will have a true idea of our Universe then!
+Knut Torgersen asked me to make this post... and here it is for your consumption. Though much has been said about the Laniakea Supercluster, this looks into the flows and size.
Cosmic Speed : The team used a database that compiles the velocities of thousands of galaxies, calculated after subtracting the average rate of cosmic expansion. “All these deviations are due to the gravitational pull galaxies feel around them, which comes from mass,” says Tully. The researchers used an algorithm to translate these velocities into a three-dimensional field of galaxy flow and density.
How did Brent Tully and his team do it? : If galaxies are clumped together closely in space they’ll orbit each other, or at least their mutual gravity will affect their motion. This in turn affects the redshift for each galaxy on top of the cosmic expansion. We know pretty well how the Universe is expanding on local scales, so if you subtract that part away, what’s left is the local motion of the galaxies. That can be used to map how gravity of other nearby galaxies is affecting them. This let them make a map of the density and movement of galaxies in space.
Size : The colossal supercluster is shown in the above computer-generated visualization, where green areas are rich with white-dot galaxies and white lines indicate motion towards the supercluster center. Galaxies flow into other galactic concentrations. The Laniakea Supercluster spans about 500 million light years and contains about 100,000 times the mass of our Milky Way Galaxy. The discoverers of Laniakea gave it a name that means "immense heaven" in Hawaiian.
Source Slate: http://www.slate.com/blogs/bad_astronomy/2014/09/04/laniakea_our_local_supercluster.html
Nature Source: http://www.nature.com/news/earth-s-new-address-solar-system-milky-way-laniakea-1.15819
Research paper: http://arxiv.org/abs/1409.0880
APOD source: http://apod.nasa.gov/apod/ap140910.html
Wikipedia reference: http://en.wikipedia.org/wiki/Laniakea_Supercluster
Video Link: Laniakea: Our home supercluster
Pics courtesy : http://goo.gl/Bsx20Q and http://goo.gl/y2MhAA
#laniakea #supercluster
2014-10-13
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