Science Current Events | Science News | Brightsurf.com
 

Scientists 'Weigh' Tiny Galaxy Halfway Across Universe

October 04, 2007

(Santa Barbara, California) -- A tiny galaxy, nearly halfway across the universe, the smallest in size and mass known to exist at that distance, has been identified by an international team of scientists led by two from the University of California, Santa Barbara.

The scientists used data collected by NASA's Hubble Space Telescope and the W. M. Keck Observatory in Hawaii. This galaxy is about half the size, and approximately one-tenth the "weight" of the smallest distant galaxies typically observed, and it is 100 times lighter than our own Milky Way.

The findings will be published in the December 20, 2007 issue of the Astrophysical Journal. The article is now available on-line at http://arxiv.org/abs/0710.0637.

"Even though this galaxy is more than six billion light years away, the reconstructed image is as sharp as the ordinary ground-based images of the nearest structure of galaxies, the Virgo cluster, which is 100 times closer to us," said lead author Phil Marshall, a postdoctoral fellow at UC Santa Barbara.

Second author Tommaso Treu, assistant professor of physics at UCSB, explained that the imaging is made possible by the fact that the newly discovered galaxy is positioned behind a massive galaxy, creating an "Einstein ring." The matter distribution in the foreground bends the light rays in much the same way a magnifying glass does. By focusing the light rays, this gravitational lensing effect increases the apparent brightness and size of the background galaxy by more than a factor of 10.

Treu and his colleagues in the Sloan Lens ACS Survey (SLACS) collaboration (http://www.slacs.org) are at forefront of the study of Einstein ring gravitational lenses. With gravitational lensing, light from distant galaxies is deflected on its way to Earth by the gravitational field of any massive object that lies in the way. Because the light bends, the galaxy is distorted into an arc or multiple separate images. When both galaxies are exactly lined up, the light forms a bull's-eye pattern, called an Einstein ring, around the foreground galaxy. See: http://www.ia.ucsb.edu/pa/display.aspx?pkey=1380.

The mass estimate for the galaxy, and the inference that many of its stars have only recently formed, is made possible by the combination of optical and near infrared images from the Hubble Space Telescope with longer wavelength images obtained with the Keck Telescope. "If the galaxy is representative of a larger population, it could be one of the building blocks of today's spiral galaxies, or perhaps a progenitor of modern dwarf galaxies," said Treu. "It does look remarkably similar to the smallest galaxies in the Virgo cluster, but is almost half the way across the universe."

Another key aspect of the research is the use of "laser guide star adaptive optics." Adaptive optics systems use bright stars in the field of view to measure the Earth's atmospheric blurring and correct for it in real time. This technique relies on having a bright star in the image as well, so it is limited to a small fraction of the night sky. The laser guide star adaptive optics system in place at the Keck Telescope uses a powerful laser to illuminate the layer of sodium atoms that exist in the Earth's atmosphere, explained Jason Melbourne, a team member from the Center for Adaptive Optics at the University of California, Santa Cruz. The laser image acts as an artificial star, bright enough to perform adaptive optics correction at an arbitrary position in the sky, thus enabling much sharper imaging over most of the sky. For more on this topic see: http://www.keckobservatory.org/article.php?id=46.

Marshall's postdoctoral fellowship research is funded by the TABASGO Foundation through UCSB. Treu's research is supported by the National Aeronautical and Space Administration (NASA), the National Science Foundation, and the Sloan Foundation.

Other researchers involved in the project are: Raphael Gavazzi of UC Santa Barbara; Kevin Bundy of the University of Toronto; S. Mark Ammons of Lick Observatory and the Center for Adaptive Optics (CfAO) at the University of California, Santa Cruz; Adam S. Bolton of the Institute for Astronomy at the University of Hawaii; Scott Burles of the Massachusetts Institute of Technology; James Larkin of the University of California, Los Angeles; David Le Mignant of the W. M. Keck Observatory and CfAO at UC Santa Cruz; David C. Koo of the Lick Observatory at UC Santa Cruz; Leon V.E. Koopmans of the Kapteyn Astronomical Institute, the Netherlands; Claire E. Max of the Lick Observatory and CfAO at UC Santa Cruz; Leonidas A. Moustakas of the Jet Propulsion Laboratory and the California Institute of Technology; Eric Steinbring of the Herzberg Institute of Astrophysics, National Research Council of Canada; and Shelly A. Wright of UCLA.

University of California - Santa Barbara


Related Galaxy Current Events and Galaxy News Articles


Measuring the Milky Way: 1 massive problem, 1 new solution
It is a galactic challenge, to be sure, but Gwendolyn Eadie is getting closer to an accurate answer to a question that has defined her early career in astrophysics: what is the mass of the Milky Way?

Scientists discover how supermassive black holes keep galaxies turned off
An international team of scientists has identified a common phenomenon in galaxies that could explain why huge numbers of them turn into cosmic graveyards.

Supermassive black holes in 'red geyser' galaxies cause galactic warming
An international team of scientists, including the University of Kentucky's Renbin Yan, have uncovered a new class of galaxies, called "red geysers," with supermassive black hole winds so hot and energetic that stars can't form.

Supermassive black hole wind can stop new stars from forming
Scientists have uncovered a new class of galaxies with supermassive black hole winds that are energetic enough to suppress future star formation.

OU astrophysicists detect most luminous diffuse gamma-ray emission from Arp 220
A University of Oklahoma team has detected for the first time the most luminous gamma-ray emission from a galaxy--the merging galaxy Arp 220 is the nearest ultraluminous infrared galaxy to Earth, and it reveals the hidden extreme energetic processes in galaxies.

The dark side of the fluffiest galaxies
Galaxies, in all their forms from spirals to ellipticals from giants to dwarfs have been widely studied over the past Century.

Astronomers confirm faintest early-universe galaxy ever seen
An international team of scientists, including two professors and three graduate students from UCLA, has detected and confirmed the faintest early-universe galaxy ever. Using the W. M. Keck Observatory on the summit on Mauna Kea in Hawaii, the researchers detected the galaxy as it was 13 billion years ago.

NASA super pressure balloon begins globetrotting journey
NASA successfully launched a super pressure balloon (SPB) from Wanaka Airport, New Zealand, at 11:35 a.m. Tuesday, May 17, 2016 (7:35 p.m. EDT Monday, May 16, 2016) on a potentially record-breaking, around-the-world test flight.

A beautiful instance of stellar ornamentation
In this image from ESO's Very Large Telescope (VLT), light from blazing blue stars energises the gas left over from the stars' recent formation.

Hubble spies a spiral snowflake
Together with irregular galaxies, spiral galaxies make up approximately 60 percent of the galaxies in the local universe.
More Galaxy Current Events and Galaxy News Articles

The Hitchhiker's Guide to the Galaxy

The Hitchhiker's Guide to the Galaxy
by Douglas Adams (Author)


"IRRESISTIBLE!"
--The Boston Globe
Seconds before the Earth is demolished to make way for a galactic freeway, Arthur Dent is plucked off the planet by his friend Ford Prefect, a researcher for the revised edition of The Hitchhiker's Guide to the Galaxy who, for the last fifteen years, has been posing as an out-of-work actor.
Together this dynamic pair begin a journey through space aided by quotes from The Hitchhiker's Guide ("A towel is about the most massively useful thing an interstellar hitchhiker can have") and a galaxy-full of fellow travelers: Zaphod Beeblebrox--the two-headed, three-armed ex-hippie and totally out-to-lunch president of the galaxy; Trillian, Zaphod's girlfriend (formally Tricia McMillan), whom Arthur tried to pick up at a cocktail party once upon a time...

Galaxy: Mapping the Cosmos

Galaxy: Mapping the Cosmos
by James Geach (Author)


Each night, we are able to gaze up at the night sky and look at the thousands of stars that stretch to the end of our individual horizons. But the stars we see are only those that make up our own Milky Way galaxy—but one of hundreds of billions in the whole of the universe, each separated  by inconceivably huge tracts of empty space. In this book, astronomer James Geach tells the rich stories of both the evolution of galaxies and our ability to observe them, offering a fascinating history of how we’ve come to realize humanity’s tiny place in the vast universe.
           
Taking us on a compelling tour of the state-of-the-art science involved in mapping the infinite, Geach offers a first-hand account of both the science itself and how it is done, describing what...

The Ultimate Hitchhiker's Guide to the Galaxy

The Ultimate Hitchhiker's Guide to the Galaxy
by Douglas Adams (Author), Neil Gaiman (Introduction)


At last in paperback in one complete volume, here are the five classic novels from Douglas Adams’s beloved Hitchiker series.

The Hitchhiker’s Guide to the Galaxy
Seconds before the Earth is demolished for a galactic freeway, Arthur Dent is saved by Ford Prefect, a researcher for the revised Guide. Together they stick out their thumbs to the stars and begin a wild journey through time and space.

The Restaurant at the End of the Universe
Facing annihilation at the hands of warmongers is a curious time to crave tea. It could only happen to the cosmically displaced Arthur Dent and his comrades as they hurtle across the galaxy in a desperate search for a place to eat.

Life, the Universe and Everything
The unhappy inhabitants of planet Krikkit are sick of...

Life, the Universe and Everything (Hitchhiker's Guide to the Galaxy)

Life, the Universe and Everything (Hitchhiker's Guide to the Galaxy)
by Douglas Adams (Author)


"HYSTERICAL!"
--The Philadelphia Inquirer
The unhappy inhabitants of planet Krikkit are sick of looking at the night sky above their heads--so they plan to destroy it. The universe, that is. Now only five individuals stand between the white killer robots of Krikkit and their goal of total annihilation.
They are Arthur Dent, a mild-mannered space and time traveler, who tries to learn how to fly by throwing himself at the ground and missing; Ford Prefect, his best friend, who decides to go insane to see if he likes it; Slartibartfast, the indomitable vicepresident of the Campaign for Real Time, who travels in a ship powered by irrational behavior; Zaphod Beeblebrox, the two-headed, three-armed ex-head honcho of the Universe; and Trillian, the sexy space cadet who is torn between a...

The Galaxy Chronicles (The Future Chronicles)

The Galaxy Chronicles (The Future Chronicles)
by Windrift Books


Space. Some call it the ultimate frontier. Humans are the verge of breaking its bonds with Earth and reaching other planets, other worlds, other galaxies. And when we do, will we go forth in peace? Or take with us our conflicts, our battles, our wars?

In this latest title in the acclaimed 'Future Chronicles' series of speculative fiction anthologies, twelve authors take us on that incredible journey with adventurers, colonists, and space marines as they push the boundaries against the unknown, against alien empires, and themselves.

"The Galaxy Chronicles" features stories by USA Today and Amazon bestselling authors Nick Webb (Constitution), Raymond L. Weil (The Lost Fleet), Jasper T. Scott (Dark Space), plus nine more of today's top authors in speculative and...

Space Camp (Galaxy Zack)

Space Camp (Galaxy Zack)
by Ray O'Ryan (Author), Jason Kraft (Illustrator)


Zack and his friends are off to space camp on a new planet in the fourteenth Galaxy Zack adventure.

Camp Among the Stars!

Summer vacation is finally here and Zack is pumped for space camp! He can’t wait to play galactic games, tell scary stories, and go on crazy camping adventures with new friends. But when there’s trouble between his cabin mates, it’s up to Zack to bring everyone together. Will he be able to find a solution before the entire summer is ruined?

With easy-to-read language and illustrations on almost every page, the Galaxy Zack chapter books are perfect for beginning readers.

The Restaurant at the End of the Universe

The Restaurant at the End of the Universe
by Douglas Adams (Author)


"DOUGLAS ADAMS IS A TERRIFIC SATIRIST."
--The Washington Post Book World
Facing annihilation at the hands of the warlike Vogons is a curious time to have a craving for tea. It could only happen to the cosmically displaced Arthur Dent and his curious comrades in arms as they hurtle across space powered by pure improbability--and desperately in search of a place to eat.
Among Arthur's motley shipmates are Ford Prefect, a longtime friend and expert contributor to the Hitchhiker's Guide to the Galaxy; Zaphod Beeblebrox, the three-armed, two-headed ex-president of the galaxy; Tricia McMillan, a fellow Earth refugee who's gone native (her name is Trillian now); and Marvin, the moody android who suffers nothing and no one very gladly. Their destination? The ultimate hot spot for an...

Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe

Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe
by Ethan Siegel (Author)


A look up at the night sky reveals a treasury of wonders. Even to the naked eye, the Moon, stars, planets, the Milky Way and even a few star clusters and nebulae illuminate the heavens. For millennia, humans struggled to make sense of what's out there in the Universe, from all we can see to that which lies beyond the limits of even our most powerful telescopes. Beyond the Galaxy traces our journey from an ancient, Earth-centered Universe all the way to our modern, 21st century understanding of the cosmos. Touching on not only what we know but also how we know it, Ethan Siegel takes us to the very frontiers of modern astrophysics and cosmology, from the birth of our Universe to its ultimate fate, and everything in between.
Readership: General public interested in astronomy,...

Journey to Juno (Galaxy Zack)

Journey to Juno (Galaxy Zack)
by Ray O'Ryan (Author), Colin Jack (Illustrator)


Join Zack as he takes a trip to the planet Juno, makes an amazing discovery, and learns the importance of teamwork!

In Journey to Juno, Zack joins his school’s Explorer’s Club and visits Juno, a newly discovered planet of crystals. The group is split into pairs as they begin exploring, and Zack is less than thrilled when he is partnered with Seth Stevens, the Phase 2 bully! Seth is happy to let Zack do the work while he goofs off, so when Zack stumbles upon a really cool object, he hides it so he can show it to the Explorer’s Club himself. But when the time comes for Zack to accept praise for his discovery, will he decide to share the credit?

With easy-to-read language and illustrations on almost every page, the Galaxy Zack chapter books are perfect for beginning...

So Long, and Thanks for All the Fish (Hitchhiker's Guide to the Galaxy)

So Long, and Thanks for All the Fish (Hitchhiker's Guide to the Galaxy)
by Douglas Adams (Author)


Back on Earth with nothing more to show for his long, strange trip through time and space than a ratty towel and a plastic shopping bag, Arthur Dent is ready to believe that the past eight years were all just a figment of his stressed-out imagination. But a gift-wrapped fishbowl with a cryptic inscription, the mysterious disappearance of Earth's dolphins, and the discovery of his battered copy of The Hitchhiker's Guide to the Galaxy all conspire to give Arthur the sneaking suspicion that something otherworldly is indeed going on. . . .

God only knows what it all means. And fortunately, He left behind a Final Message of explanation. But since it's light-years away from Earth, on a star surrounded by souvenir booths, finding out what it is will mean hitching a ride to the far reaches...

© 2016 BrightSurf.com