PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

International team identifies earliest galaxy ever detected

In a major new survey of the early universe conducted from NASA's Hubble Space Telescope, UMass Amherst astronomer Mauro Giavalisco and colleagues at other institutions identify the most distant, thus the earliest galaxy ever detected

2013-11-01
(Press-News.org) Contact information: Janet Lathrop
jlathrop@admin.umass.edu
413-545-0444
University of Massachusetts at Amherst
International team identifies earliest galaxy ever detected In a major new survey of the early universe conducted from NASA's Hubble Space Telescope, UMass Amherst astronomer Mauro Giavalisco and colleagues at other institutions identify the most distant, thus the earliest galaxy ever detected

AMHERST, Mass. -- In a major new survey of the early universe conducted from the NASA's Hubble Space Telescope, University of Massachusetts Amherst astronomer Mauro Giavalisco and colleagues at several other institutions identify the most distant, thus the earliest galaxy ever detected.

Although other Hubble-based observations have identified many other candidates for galaxies in the early universe, including some that may be even more distant, this galaxy is the farthest and earliest whose distance can be definitively confirmed with follow-up observations from the Keck I telescope, one of the largest on earth.

The surprise finding of a young galaxy from a survey that was not designed to find such bright early galaxies suggests that the infant universe may harbor a larger number of intense star-forming galaxies than astronomers believed possible, say first author Steve Finkelstein of the University of Texas (UT) at Austin, Giavalisco and others writing in a recent issue of Nature. This means theories and predictive models of the distribution of galaxies' star formation activity may need revision.

"We expected to find a lot more small objects with this survey," says Giavalisco. In the same way physics predicts that throwing a brick through a window should produce a huge number of small shards and very few large pieces, he adds, theory predicts there should be "many small-mass galaxies but just a few large ones. And our survey was not really designed to find these early galaxies with such a high rate of star formation. However, on the first try we see this very active object. So we're not sure if we're really, really lucky or if our predictive models are slightly off."

The high luminosity, powered by star formation activity, of this new galaxy "raise a tantalizing question about whether we've got the theory of galaxy formation correct in its fundamental ideas," the astronomer adds. "Predictions about the star formation rate distribution of galaxies are related to the physics of gas accretion onto galaxies and subsequent gas expulsion from them. These mechanisms are not yet fully understood."

The team, with researchers from Israel, Italy, Arizona, Maryland, California and Kentucky with UMass Amherst and UT, used two special cameras on Hubble as part of the largest investigation of the distant universe ever made with the space telescope.

To identify this distant galaxy from among myriads of other, closer faint galaxies that obscure deep images of the sky, they used a technique called the "Lyman-break selection" developed by Giavalisco and others in the 1990s. It exploits the apparent colors of galaxies as a crude distance indicator. "Colors encode a lot of physical processes at work in them," he points out, "such as whether they form stars or not and how much dust is in them, because dust dims stellar light and makes their colors redder."

"Thanks to the Lyman-break selection, we can cull the very rare, genuinely distant galaxies from the much more abundant dust-reddened nearby ones with great confidence, making the study of the distant universe possible," he adds.

But the Lyman-break technique yields only crude distance estimates, so astronomers need to accurately determine the distance to pre-selected remote galaxies, and hence the age at which they are being observed, not only to accurately date the galaxy, but also to accurately measure its mass, luminosity and star-formation activity.

To measure the distance to this record-breaking galaxy, Finkelstein, Giavalisco and colleagues needed very sensitive spectroscopic telescopes to detect a specific spectral feature emitted by hydrogen known as the Lyman-alpha emission line. It is emitted in a very narrow range of ultraviolet wavelengths, invisible to the human eye. "But if our galaxy is really so distant from us, then the fast cosmic expansion that existed at its early days would be redshifted because of the expanding universe from its apparent wavelength to infrared wavelengths," Giavalisco points out.

To detect the Lyman-alpha emission from such a distant galaxy and fully confirm its nature, the team used the Keck 10-meter telescope in Hawaii, a very powerful spectroscopic instrument. Results yielded a redshift parameter, that is an indicator of distance, of z = 7.51, by far the most distant galaxy ever recorded. At that time the universe was only 700 million years old, compared to 13.8 billion years today. It was 8.5 times smaller than today, 600 times more dense and expanding 8.5 times faster.

Lyman alpha light is also a powerful probe of the early universe. It cannot penetrate the neutral hydrogen gas that envelops young galaxies because the gas's atoms very easily absorb it, Giavalisco says. It can, however, propagate freely through ionized gas bubbles around older, more evolved galaxies. Thus, detecting Lyman-alpha from a very early galaxy suggests that its neutral hydrogen volume is small.

"This is a very important piece of information about cosmic re-ionization," the astronomer points out. Re-ionization is a crucial phase of cosmic evolution that happened when the universe went from being a distribution of cold neutral gas with no light sources, also known as the Dark Age, to being fully ionized.

"We believe that the energy to ionize the hydrogen came from the first stars and the first quasars, which ended the Dark Age, lifted its cold fog and made the cosmos transparent to Lyman alpha light," Giavalisco says. Thus, this study moves science closer to answering a long-standing mystery about how cosmic re-ionization proceeds. If the theory of the Big Bang is correct, we must see the recombination of the ionized plasma into a neutral gas, or re-ionization."



INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Brushing your teeth could prevent heart disease

2013-11-01
Brushing your teeth could prevent heart disease Prospective study finds clinically significant difference in atherosclerosis progression based on changes in periodontal health Taking care of your gums by brushing, flossing, and regular ...

Animal welfare scientists reveal infrequent and inconsistent acceptance of existing data by EPA to satisfy endocrine disruptor testing requirements

2013-11-01
Animal welfare scientists reveal infrequent and inconsistent acceptance of existing data by EPA to satisfy endocrine disruptor testing requirements Norfolk, Va. – An original article by scientists at People for the Ethical Treatment of Animals ...

Mid-level health workers as effective as physicians

2013-11-01
Mid-level health workers as effective as physicians This news release is available in Spanish, French, Portuguese and Arabic. Countries facing severe shortages and poor distribution of health workers could benefit from training and deploying more ...

A new weapon in the fight against superbugs

2013-11-01
A new weapon in the fight against superbugs The ever-increasing threat from "superbugs" -- strains of pathogenic bacteria that are impervious to the antibiotics that subdued their predecessor generations -- has forced the medical community to look for bactericidal ...

Patients' 'immune fingerprints' may help diagnose bacterial infections and guide treatment

2013-11-01
Patients' 'immune fingerprints' may help diagnose bacterial infections and guide treatment Body's immune response indicates type of infection and which antibiotics to use Washington, DC (October 31, 2013) — A patient's immune response may provide better and more ...

New techniques produce cleanest graphene yet

2013-11-01
New techniques produce cleanest graphene yet Columbia Engineers develop new device architecture for 2D materials, making electrical contact from the 1D edge New York, NY—October 31, 2013—Columbia Engineering researchers have experimentally demonstrated for the ...

Global warming as viewed from the deep ocean

2013-11-01
Global warming as viewed from the deep ocean The intermediate waters of the Pacific Ocean are absorbing heat 15 times faster over the past 60 years than in the past 10,000 Some climate change skeptics have pointed out that global atmospheric temperatures ...

Is global heating hiding out in the oceans?

2013-11-01
Is global heating hiding out in the oceans? Parts of pacific warming 15 times faster than in past 10,000 years A recent slowdown in global warming has led some skeptics to renew their claims that industrial carbon emissions are not ...

Making electrical contact along 1-D edge of 2-D materials

2013-11-01
Making electrical contact along 1-D edge of 2-D materials As postdoc at Columbia, CCNY physicist Cory Dean and colleagues devised new method that addresses graphene's contamination problem Dr. Cory Dean, assistant professor of physics at The City College of New ...

Researchers identify molecule that orients neurons for high definition sensing

2013-11-01
Researchers identify molecule that orients neurons for high definition sensing Many animals have highly developed senses, such as vision in carnivores, touch in mice, and hearing in bats. New research from the RIKEN Brain Science Institute has uncovered a brain molecule that can explain ...

LAST 30 PRESS RELEASES:

Printed skin to replace animal testing

Precision medicine could be possible in the fight against antibiotic resistance

Researchers at the Lewis Katz School of Medicine at Temple University identify new targeted approach to protect neurons against degeneration

Western diet causes inflammation, traditional African food protects

Electrochemical method supports nitrogen circular economy

How researchers are shining a light on kidney disease

Some gut bacteria could make certain drugs less effective

PEPITEM sequence shows effects in psoriasis, comparable to steroid cream

Older teens who start vaping post-high school risk rapid progress to frequent use

Corpse flowers are threatened by spotty recordkeeping

Riding the AI wave toward rapid, precise ocean simulations

Are lifetimes of big appliances really shrinking?

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

[Press-News.org] International team identifies earliest galaxy ever detected
In a major new survey of the early universe conducted from NASA's Hubble Space Telescope, UMass Amherst astronomer Mauro Giavalisco and colleagues at other institutions identify the most distant, thus the earliest galaxy ever detected