New Galactic Supercluster Map Shows Milky Way's 'Heavenly' Home

[Buster's Uncle]

New Galactic Supercluster Map Shows Milky Way's 'Heavenly' Home
SPACE.com
by Charles Q. Choi, SPACE.com Contributor  11 minutes ago



A new cosmic map is giving scientists an unprecedented look at the boundaries for the giant supercluster that is home to Earth's own Milky Way galaxy and many others. Scientists even have a name for the colossal galactic group: Laniakea, Hawaiian for "immeasurable heaven."

The scientists responsible for the new 3D map suggest that the newfound Laniakea supercluster of galaxies may even be part of a still-larger structure they have not fully defined yet.

"We live in something called 'the cosmic web,' where galaxies are connected in tendrils separated by giant voids," said lead study author Brent Tully, an astronomer at the University of Hawaii at Honolulu.


Galactic structures in space

Galaxies are not spread randomly throughout the universe. Instead, they clump in groups, such as the one Earth is in, the Local Group, which contains dozens of galaxies. In turn, these groups are part of massive clusters made up of hundreds of galaxies, all interconnected in a web of filaments in which galaxies are strung like pearls. The colossalstructures known as superclusters form at the intersections of filaments.

The giant structures making up the universe often have unclear boundaries. To better define these structures, astronomers examined Cosmicflows-2, the largest-ever catalog of the motions of galaxies, reasoning that each galaxy belongs to the structure whose gravity is making it flow toward.

"We have a new way of defining large-scale structures from the velocities of galaxies rather than just  looking at their distribution in the sky," Tully said.

Laniakea: Our home supercluster

Laniakea, our home in the universe

The new 3D map developed by Tully and colleagues shows that the Milky Way galaxy resides in the outskirts of the Laniakea Supercluster, which is about 520 million light-years wide. The supercluster is made up of about 100,000 galaxies with a total mass about 100 million billion times that of the sun.

The name Laniakea was suggested by Nawa'a Napoleon, who teaches Hawaiian language at Kapiolani Community College in Hawaii. The name is meant to honor Polynesian navigators who used their knowledge of the heavens to make long voyages across the immensity of the Pacific Ocean.

"We live in the Local Group, which is part of the Local Sheet next to the Local Void — we wanted to come up with something a little more exciting than 'Local,'" Tully told Space.com.

This supercluster also includes the Virgo cluster and Norma-Hydra-Centaurus, otherwise known as the Great Attractor. These new findings help clear up the role of the Great Attractor, which is a problem that has kept astronomers busy for 30 years. Within the Laniakea Supercluster, the motions of galaxies are directed inward, as water flows in descending paths down a valley, and the Great Attractor acts like a large flat-bottomed gravitational valley with a sphere of attraction that extends across the Laniakea Supercluster.

Tully noted Laniakea could be part of an even larger structure.

"We probably need to measure to another factor of three in distance to explain our local motion," Tully said. "We might find that we have to come up with another name for something larger than we're a part of — we're entertaining that as a real possibility."

The scientists detailed their findings in the Sept. 4 issue of the journal Nature.


http://news.yahoo.com/galactic-supercluster-map-shows-milky-ways-heavenly-home-170825956.html

[Geo]

So we moved Clusters?

[Buster's Uncle]

Sure.

[Buster's Uncle]

New map shows Milky Way lives in Laniakea galaxy complex
Reuters
By Irene Klotz  32 minutes ago



CAPE CANAVERAL Fla. (Reuters) - The Milky Way galaxy resides on the outskirts of a massive, previously unknown galaxy super-cluster scientists have named Laniakea, from Hawaiian words for "immeasurable heaven."

The discovery, reported in this week's issue of the journal Nature, stems from a new mapping technique that combines not only the distances between more than 8,000 nearby galaxies, but also their relative motions.

The technique enables astronomers for the first time to clearly delineate where one super-cluster of galaxies ends and another gravitationally bound super-cluster structure begins.

The new maps show the Milky Way galaxy, along with the Virgo cluster and some 100,000 other galaxies, are gravitationally sailing in the same gigantic cosmic pool, named Laniakea.

The super-cluster spans some 520 million light-years in diameter. One light-year is the distance that light, which moves at about 186,000 miles per second (300,000 km/s), travels in one year, or roughly 5.88 trillion miles (9.46 trillion km).

Scientists previously believed the Milky Way galaxy, which is where Earth and the rest of the solar system reside, was part of a cluster measuring about 100 million light-years in diameter. The new study shows that structure is just an appendage of the larger Laniakea.

Bordering Laniakea are the Shapley, Hercules, Coma and Perseus-Pieces super-clusters, though the far edges of the neighboring galaxy complexes have not yet been determined. Thousands more distance measurements will be needed for that, said astronomer and lead researcher Brent Tully, with the University of Hawaii.

"We haven’t seen the edges of our neighbors and we haven’t seen far enough to understand what’s causing this full motion of our galaxy,” Tully said in an interview.

Having a clear method for identifying super-clusters is expected to help scientists piece together a better idea of how galaxies, including the Milky Way, evolve, astronomer Elmo Tempel, with the Tartu Observatory in Estonia, said in a related Nature commentary.

“Hopefully, this will initiate observational programs to carry out additional direct-distance measurements of galaxies,” Tempel wrote in an email to Reuters.

(Editing by Mohammad Zargham)


http://news.yahoo.com/map-shows-milky-way-lives-laniakea-galaxy-complex-191432082.html

[Buster's Uncle]

Say hello to Laniakea, our cosmic neighbourhood
AFP
7 minutes ago



A multiple exposure picture taken in the early hours of August 12, 2014 shows a Perseids meteor shower in the night sky from the mountains of the Sierra Norte de Madrid near the municipality of Valle del Lozoya (AFP Photo/Dani Pozo)



Paris (AFP) - Astronomers said Wednesday they have mapped the galaxy supercluster of which our Solar System forms a tiny part, and named the mighty mass Laniakea, or "immense heaven" in the language of Hawaii.

Laniakea comprises some 100,000 galaxies with about a hundred million billion suns, they reported in the journal Nature.

It would take 500 million years, travelling at the speed of light, to travel from one end of the supercluster to the other.

Galaxies are not distributed randomly throughout the Universe, tending instead to group together. They are connected by a "cosmic web" comprising filaments of matter, tugged by gravity.

Sometimes, thousands of galaxies can crowd together at the intersections of these filaments. But determining the boundaries of these so-called superclusters -- defining the regions of space they dominate -- has been a big debate.

A team led by Brent Tully at the Institute for Astronomy at the University of Hawaii at Manoa, used a new method to map the supercluster that includes our home.

The team delved into a vast database of galaxies, singling out 8,000 that lie in our cosmic neighbourhood, and studied their motion.

They calculated each galaxy's location by estimating its velocity relative to the expansion of the Universe -- the movement initiated by the "Big Bang" some 14 billion years ago.

The biggest challenge was to figure out a phenomenon called the Great Attractor, a flat-bottomed gravitational "valley" within the supercluster.

The Great Attractor has complicated the bid to define this particular supercluster for decades.

It muddles calculations about the motion of galaxies because many are drawn into its "valley" -- in the same way that water flows down a slope -- even as they experience the outward force exerted by the expansion of the Universe.

Learning about the gravitational machinery of the Great Attractor, the team realised that our supercluster is far bigger than thought. Previous estimates had put it at about 100 million light years across.

The Milky Way, the galaxy that includes our star system, lies on the outskirts of Laniakea, according to a Nature video of the new map (

! Video not found

).

The name Laniakea was proposed by Nawa'a Napoleon, a professor of the Hawaiian language at the university.

It honours Polynesian navigators who used knowledge of the stars to make extraordinary travels across the Pacific.


http://news.yahoo.com/hello-laniakea-cosmic-neighbourhood-220546851.html

[Geo]

So that would make the width of our 'local supercluster' about 1/40th the size of the observable Universe?

[Buster's Uncle]

1/26th, I think.

[Geo]

We should be able to observe roughly 13 billion lightyears in ALL directions. 1/52th+?

[Buster's Uncle]

I believe you're right.

[Buster's Uncle]

This is the most detailed map yet of our place in the universe
Vox
Updated by Brad Plumer on September 4, 2014, 11:20 a.m. ET @bradplumer brad@vox.com



A new study in Nature finds that the Milky Way is part of a broader supercluster of 100,000 galaxies known as Laniakea.  Nature Video 



We know that the Earth and the solar system are located in the Milky Way galaxy. But how, exactly, does the Milky Way fit in among the billions of other galaxies in the known universe?

In a fascinating new study for Nature, a team of scientists mapped thousands of other galaxies in our immediate vicinity, and discovered that the Milky Way is part of a truly massive "supercluster" of galaxies that they named Laniakea.

This structure is much bigger than astronomers had previously realized. It contains more than 100,000 galaxies, stretches 500 million light years across, and looks something like this (the Milky Way is located on one of its fringes on the right):


Say hello to Laniakea, our local supercluster

(Nature Video, based on Tully et al 2014)

So how did they figure out this structure existed — and how did they distinguish it from other structures?

The team of scientists, led by R. Brent Tully of the University of Hawaii, first studied the motion of some 8,000 galaxies in our neighborhood. By doing so, they could map out certain striking patterns. The universe overall has been expanding ever since the Big Bang. But the team also found that gravity was pulling some galaxies toward each other.


That helped them build the chart below, where galaxies moving away from us are shown in red, and the galaxies moving toward us in blue.


The galaxies around us are moving in identifiable patterns

Galaxies moving away from us are in red, those moving toward us in blue (Nature Video, based on Tully et al 2014)

That, in turn, let them create a map of the pathways along which all the galaxies are moving and demarcate some boundaries.


The map below shows some of the pathways within our broader supercluster of galaxies. There's an especially dense region called "The Great Attractor" (in red) that's slowly pulling the Milky Way and many other galaxies toward it:


Many galaxies in Laniakea are being pulled toward the "Great Attractor"

(Nature Video, based on Tully et al 2014)

What's interesting is that this structure is much, much bigger than anyone had realized. Astronomers had long grouped the Milky Way, Andromeda, and other galaxies around us in the Virgo Supercluster, which contained some 100 galaxy groups.

But as Tully and his colleagues found, this Virgo Supercluster is just part of a much, much bigger supercluster — Laniakea. (The name, aptly enough, means "immeasurable heavens" in Hawaiian.)

So what happens when we zoom out? The paper notes that Laniakea borders another supercluster known as Perseus-Pisces. And the scientists defined the borders as where the galaxies diverge:

Laniakea borders another supercluster: Perseus-Pisces

(Nature Video, based on Tully et al 2014)

What happens if we zoom out even further? Even Laniakea and Perseus-Pisces are just one small corner of the much broader universe. That universe consists of both voids and densely packed superclusters of galaxies. It looks something like this:


And... zooming out to the broader universe

(Nature Video, based on Tully et al 2014)

We still don't have detailed maps of every last galaxy supercluster out there. But we now have one for our own home supercluster — and that's certainly a start.


Further watching: There's an excellent video from Nature breaking down the team's findings. The stills above come from that video.

Laniakea: Our home supercluster

Further reading: Over at Slate, Phil Plait has a nice breakdown of the new study.


http://www.vox.com/2014/9/4/6105631/map-galaxy-supercluster-laniakea-milky-way

[Geo]

And... zooming out to the broader universe

(Nature Video, based on Tully et al 2014)

Too bad, Laniakea isn't marked in this shot.

[Buster's Uncle]

Looks organic, doesn't it?

[Buster's Uncle]

Earth's address within a massive supercluster of 100,000 galaxies
CNET CBS
By Michelle Starr  34 minutes ago



Screenshot by Michelle Starr/CNET



The distribution of galaxies throughout the universe is not more-or-less even; instead, galaxies tend to cluster together, bound together by the pull of each other's gravity. These groups can be a variety of sizes. The Milky Way Galaxy, for instance, is part of what is called the Local Group, which contains upwards of 54 galaxies, covering a diameter of 10 megalight-years (10 million light-years).

But this Local Group is just a small part of a much, much bigger structure, which researchers at the University of Hawai'i Mānoa have now mapped in detail. Coming in at over 100,000 galaxies, the massive supercluster has been given the name Laniakea -- "immense heaven" in Hawaiian.

The new 3D map was created by examining the positions and movements of the 8000 closest galaxies to the Milky Way. After calculating which galaxies were being pulled away from us and which were being pulled towards us -- accounting for the universe's expansion -- the team, led by astronomer R. Brent Tully, was able to map the paths of galactic migration -- and define the boundaries of Laniakea.

Traditionally, the borders of galactic superclusters have been difficult to map, but studying the gravitational force acting on our neighbouring galaxies has provided some important clues. All objects inside Laniakea are being slowly but surely drawn to a single point -- a force known as the Great Attractor, a gravitational anomaly with a mass tens of thousands of times the mass of the Milky Way.

Everything that is being pulled towards the Great Attractor is part of Laniakea -- although it's possible that Laniakea itself might in turn be part of a structure that is larger still.

"We probably need to measure to another factor of three in distance to explain our local motion," Tully said. "We might find that we have to come up with another name for something larger than we're a part of -- we're entertaining that as a real possibility."

The full paper, "The Laniakea supercluster of galaxies", can be read online in the journal Nature.


http://news.yahoo.com/earths-address-within-massive-supercluster-011609546.html