Clipmarks | Galaxies Clips

High speed crash makes galaxies 'sterile'

Fri, 10 Oct 2008 07:03:34 GMT

clipped by: pokkets

Larry O'Hanlon

A new view of two very well-known galaxies has revealed they are connected by faint, starless filaments of hydrogen gas, which trace back to a very high-speed intergalactic collision.

The smash-up between M86 and NGC4438 had not been suspected before, and may explain why M86, which is visible to the naked eye, is unable to give birth to new stars.

"Stars and gases behave very differently in collisions," says astronomer Professor Jeffrey Kenney of Yale University and lead author of a paper in the November 2008 issue of Astrophysical Journal Letters.

During galactic smash-ups stars rarely collide, since there is so much space between them. But gases do slam into gases. The faster the collision, the higher the temperature the gases reach.

In the case of M86, its gases are millions of degrees in temperature and radiate x-rays.

The new evidence of M86's collision may solve that mystery. What's more, the super-hot gas also probably explains why M86 is unable to produce new stars.

High-Speed Crash Makes Hot, 'Sterile' Galaxies

Thu, 09 Oct 2008 20:37:46 GMT

clipped by: invictus

Clip Source: dsc.discovery.com

Oct. 9, 2008 -- A new wider view of two very well-known galaxies has revealed a big surprise: They are connected by faint, starless filaments of hydrogen gas which trace back to a very high-speed intergalactic collision.

The smash-up between galaxies M86 and NGC4438 not been suspected before, and may explain why M86, which is visible to the naked eye, is unable to give birth to new stars.

Tags: space, universe, galaxies, science

Scientists meet for alien summit

Wed, 08 Oct 2008 20:07:07 GMT

clipped by: kkcapricorn
clipper's remarks: I hope they share some of their findings and information with the public

Clip Source: news.bbc.co.uk

An artists impression of the planet going around the star Vega, which the Scuba 2 instrument discovered

The origins of life in our galaxy and the search for alien life outside our solar system will be at the forefront of discussions by experts in Edinburgh

'Are We Alone?'.

There are now more than 300 planets known beyond our own Solar System.

Known as exo-planets, they are likely to be discovered with the completion of instruments such as Scuba 2, a camera to detect dust from the earliest phases of the formation of galaxies and, in the near future, the James Webb Space Telescope, an orbiting telescope to catch the first light of the universe.

The aim of the workshop is to gather researchers from areas including astrophysics, geophysics and biology to discuss astronomical instruments, both present and future, and laboratory based experiments studying extreme environments.

key speakers in astrobiology, atmospheric physics and astrophysics

Tags: universe, alien life, summit, astrophysics

Galaxies found to be flowing together

Sun, 05 Oct 2008 02:44:48 GMT

clipped by: Kelika
clipper's remarks: "He said another interesting idea proposed since the cosmic flow was detected is that instead of a gravitational pull by something beyond the observable universe, the galaxies are being pushed by an absence of mass in the local universe."

Clip Source: www.starbulletin.com

Hundreds of galaxy clusters are flowing toward the same spot in the sky beyond the observable universe, a University of Hawaii astronomer and NASA team members have discovered.

The clusters, each with hundreds of millions of stars, are moving at more than 1 million mph toward the constellations Centaurus and Vela, said Harald Ebeling, co-author of a paper on the baffling finding in the Astrophysical Journal Letters.

"It's pretty bizarre," he said in an interview.

Ebeling said the "main culprit" behind the phenomenon seems to be the Shapley Concentration, a giant supercluster made up of about 25 galactic clusters about 700 million light-years away which pulls everything toward it.

But once the clusters reach the Shapley supercluster, he said, they do not subside or reverse -- they defy current cosmic theories and keep on going.

Tags: space

Two Spiral Galaxies Collide

Thu, 02 Oct 2008 09:23:02 GMT

clipped by: tabsey
clipper's remarks: There goes the weekender.

Clip Source: news.yahoo.com

Hubble & Spitzer Space Telescopes

Tags: astronomy

How A Catholic Priest Gave Us The Primeval Atom Theory

Mon, 29 Sep 2008 09:37:13 GMT

clipped by: merrie
clipper's remarks: Returning to Belgium in 1925, where he worked at the Catholic University of Leuven as a part-time lecturer, his big break came two years later in 1927 when he proposed his theory of an expanding Universe to explain the movement of the galaxies, published in the Annals of the Scientific Society of Brussels.

Lemaitre was still pretty hazy about how the process of expansion could have begun. Like many scientists, he was still committed to the idea of a static Universe of unchanging size...

Einstein, though interested, was largely dismissive, telling Lemaitre that, "Your calculations are good, but your physics is terrible". Einstein was also a little suspicious of the religious implications of these ideas. He declined to describe himself as an atheist (or a theist, or a pantheist) and liked to use the vocabulary of religion, most famously in his misguided rejection of much of quantum physics, "God does not play dice!"

British physicist, Fred Hoyle coined the Big Bang term

Clip Source: www.americanchronicle.com

In addition to discovering these galaxies, Hubble also discovered something significant about them. Just as the pitch of a siren on an emergency vehicle changes as it drives past us - because the length of the sound waves change as they become more distant according to the Doppler effect - so too the light from distant objects can tell us whether they are moving closer or drifting away.

Together with Milton L. Humason, Hubble showed that the galaxies were moving further away from us

But, unknown to either of them, Hubble was actually beaten to the basic idea of Hubble’s Law by a Belgian priest, Fr. Georges Lemaitre. Lemaitre trained as a Jesuit priest, served in the Belgian Army during the remorseless slaughter of World War One, and then became a student of astronomy and mathematics. He studied in Cambridge in England, then in Cambridge, Massachusetts for the Harvard Observatory and finally the Massachusetts Institute of Technology.

Tags: hubble, einstein, hoyle, fr. georges lemaitre, hawkings

Giant Red Stars set a new Standard

Fri, 26 Sep 2008 06:03:17 GMT

clipped by: pokkets
clipper's remarks: The most common red giants are the so-called red giant branch stars (RGB stars) whose shells are still fusing hydrogen into helium, while the core is inactive helium.
Prominent bright red giants in the night sky include Aldebaran (Alpha Tauri), Arcturus (Alpha Bootis), and Gamma Crucis (Gacrux), while the even larger Antares (Alpha Scorpii) and Betelgeuse (Alpha Orionis) are red supergiants.

Clip Source: www.abc.net.au

Heather Catchpole

Australian and US scientists have found that a 'secondary' method of measuring the distance to nearby galaxies is more robust than previously thought.

Astrophysicists Professor Jeremy Mould from the University of Melbourne and Dr Shoko Sakai from the University of California, Los Angeles, tested the reliability of using stars from the tip of the red giant branch (TRGB) to calculate distance. They found these stars to be just as good, if not better than Cepheids.

Their research has been accepted for publication in the Astrophysical Journal.

Clip Source: en.wikipedia.org

Clip Source: www.abc.net.au

Astronomers measure distance in space using various methods depending on how far away the stars are.

For nearby distances, Cepheid variables - bright stars that expand and contract by 10% - have long been the primary 'standard candles' used.

"The question has been whether the relationship is more complicated than we think. Things like the composition of the star may make a difference," says Mould.

Clip Source: en.wikipedia.org

include Aldebaran

Stars Migrate Through Galaxies, Study Suggests

Thu, 25 Sep 2008 15:04:23 GMT

clipped by: dannyhurt28
clipper's remarks: About half the stars in our celestial neighborhood may have traveled great distances through the Milky Way, according to a new study, which suggests our sun may be one of them.

Clip Source: news.nationalgeographic.com

Stars Migrate Through Galaxies, Study Suggests

About half the stars in our celestial neighborhood may have traveled great distances through the Milky Way, according to a new study, which suggests our sun may be one of them.

People have generally assumed that once a star forms inside a galactic disk, it stays in a more or less fixed orbit around the center of its galaxy, said lead study author Rok Roškar, a graduate student in astronomy at the University of Washington in Seattle.

Tags: stars migrate

Is a Dark-Matter Galaxy Orbiting the Milky Way?

Thu, 25 Sep 2008 12:33:01 GMT

clipped by: tabsey

Clip Source: www.dailygalaxy.com

We now know about two dozen of these satellite galaxies. One of the most recent is "Segue 1", uncovered by the Sloan Digital Sky Survey (SDSS), whose extremely low light-to-mass ratio makes it a particularly significant cosmic find. Despite having a mass of a million suns it is nowhere near as luminous as astronomers would expect, with only a couple of hundred stars visible. They think "How can so much matter be so dark?", then they go "Dark matter!" and at this point we like to believe their monocle flies out and they dash down the street shouting Eureka.

Of course, the actual physics of arriving at this conclusion is a tiny bit more complicated, but the result is the same: Marla Geha (Yale professor of astronomy) and colleagues believe that it's a galaxy composed mainly of dark matter. A handy thing to have around when you're trying to study the stuff or even prove that it exists.

These mini-galaxies and other previously unobservable objects offer a wealth of data on galaxy formation

Tags: astronomy

IS THERE INTELLIGENT LIFE- OUT THERE?

Thu, 25 Sep 2008 04:46:10 GMT

clipped by: klippety
clipper's remarks: 'Cause there doesn't seem to be any here. We can only hope.......

Clip Source: www.sciam.com

Rivers of Stars Found in Milky Way

RIVERS RUN THROUGH IT:

Astronomers have discovered nearly a dozen new stellar rivers—strings of moving stars—over the disk of the Milky Way. The streams, which seem to represent smaller galaxies torn apart by our own, come from scans of the velocities of about a quarter million stars in our galaxy made for the Sloan Digital Sky Survey. Prior scans had turned up a few narrow rivers such as one extending from the star cluster NGC 5466, 76,000 light-years away, that covers 45 degrees across the northern sky. The 11 new entries form a tangle that's harder to separate. Researchers believe that the streams arose separately when neighboring star clusters known as dwarf galaxies were drawn apart like taffy by the Milky Way's larger gravitational field. They say the new findings, reported at a conference this week, could be used to improve models of galaxies colliding with and cannibalizing one another.

Is a Dark-Matter Galaxy Orbiting the Milky Way?

Wed, 24 Sep 2008 22:57:37 GMT

clipped by: spherepet

Clip Source: www.dailygalaxy.com

Is a Dark-Matter Galaxy Orbiting the Milky Way?

September 23, 2008

The SDSS has made many such observations possible, picking out objects in the sky which have the bad manners not to twinkle

despite being little stars

Tags: galaxy, milkyway

Galaxy Clusters Have a Mysterious Motion

Wed, 24 Sep 2008 22:42:55 GMT

clipped by: spherepet

Clip Source: www.physorg.com

Galaxy Clusters Have a Mysterious Motion

September 24, 2008

(PhysOrg.com) -- The stars are in motion, and on a much larger scale than can be explained with current theories, according to astronomers at NASA, the University of Hawaii and UC Davis. The finding could improve our understanding of events in the first moments after the birth of the universe.

Local flows of galaxies and galaxy clusters are well-known, said Dale Kocevski, a postdoctoral researcher at UC Davis who was part of the team. For instance, our own Milky Way galaxy is moving toward the Andromeda galaxy, and the galaxy group that includes both Andromeda and the Milky Way is moving at about 600 kilometers a second.

newly detected motion is over far too large an area to be explained

matter -- both stars, dust and gas and the more abundant but invisible "dark matter" -- is distributed in uneven clumps, and gravity pulls galaxy clusters toward those clumps

anisotropies

catalog of 700 galaxy clusters observed with X-ray astronomy

Tags: galaxy clusters, anisotropies

Mysterious New 'Dark Flow' Discovered in Space

Tue, 23 Sep 2008 20:58:11 GMT

clipped by: mugofcoffee
clipper's remarks: They discovered that the clusters were moving nearly 2 million mph (3.2 million kph) toward a region in the sky between the constellations of Centaurus and Vela. This motion is different from the outward expansion of the universe (which is accelerated by the force called dark energy).

Clip Source: www.livescience.com

By Clara Moskowitz, Staff Writer

The galaxy cluster 1E 0657-56 (known as the Bullet Cluster) lies 3.8 billion light-years away. It's one of hundreds that appear to be carried along by a mysterious cosmic flow. Credit: NASA/STScI/Magellan/U.Arizona/D.Clowe et al.

Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow."

The stuff that's pulling this matter must be outside the observable universe, researchers conclude.

discovered the flow by studying some of the largest structures in the cosmos: giant clusters of galaxies. These clusters are conglomerations of about a thousand galaxies, as well as very hot gas which emits X-rays. By observing the interaction of the X-rays with the cosmic microwave background (CMB), which is leftover radiation from the Big Bang

StarCAVE

Mon, 22 Sep 2008 10:23:25 GMT

clipped by: balthazarus
clipper's remarks: Looks like an amazing experience...

Clip Source: gizmodo.com

UCSD's StarCAVE Is a Real 3D Super-High-Def Danger Room

UC at San Diego has the closest thing to an X-Men-style Danger Room in its new StarCAVE, a small room that entirely surrounds you, hurtling 68 million pixels at your eyeballs at near-perfect resolution

Pop on polarized glasses and the whole thing goes 3D. Grasping a wireless "wand," you can walk through tall buildings, fly over cities, pick apart tiny cell structures or embrace entire galaxies. All the while pretending to do actual academic research, of course

The room—the third and by far best generation of the "Cave Automated Virtual Environment"

each panel gets its own serious processing muscle: a quad-core Linux-based PC with dual Nvidia GPUs and gigabit ethernet (in some cases 10-gigabit)

Lest you were worried about an appropriately complementary sound system, fear not. There are three five-speaker arrays hidden behind the panels for all kinds of surround-sound configurations, and there's a subwoofer built into the floor, too.

Tags: technology, 3d

Milky Way ringed by 'missing galaxies'

Sat, 20 Sep 2008 19:06:46 GMT

clipped by: invictus

Clip Source: www.cosmosmagazine.com

SYDNEY: The Milky Way could be surrounded by up to 2,000 small galaxies, too faint to be seen with current technology, say astrophysicists.

Their research has implications for understanding how galaxies form and the nature of dark matter – the invisible matter that pervades and surrounds all galaxies, including our own.

Astronomers know of 24 satellite galaxies of the Milky Way, including the two bright Magellanic Clouds, which on dark nights are visible just to the side of the wide band of the Milky Way.

But the U.S. researchers, led by astrophysicist Erik Tollerud from the University of California, Irvine, say there are at least 400 and as many as 2,000 more satellite galaxies – we just haven't spotted them yet because they are so faint.

Tags: galaxies, milky way, astronomy, science