Astronomers find most distant galaxy candidate yet seen

Study pushes the limits of Hubble's capabilities, finds evidence of rapid build-up of early galaxies

2011-01-27

(Press-News.org) SANTA CRUZ, CA--Astronomers studying ultra-deep imaging data from the Hubble Space Telescope have found what may be the most distant galaxy ever seen, about 13.2 billion light-years away. The study pushed the limits of Hubble's capabilities, extending its reach back to about 480 million years after the Big Bang, when the universe was just 4 percent of its current age.

"We're getting back very close to the first galaxies, which we think formed around 200 to 300 million years after the Big Bang," said Garth Illingworth, professor of astronomy and astrophysics at the University of California, Santa Cruz.

Illingworth and UCSC astronomer Rychard Bouwens (now at Leiden University in the Netherlands) led the study, which will be published in the January 27 issue of Nature. Using infrared data gathered by Hubble's Wide Field Planetary Camera 3 (WFC3), they were able to see dramatic changes in galaxies over a period from about 480 to 650 million years after the Big Bang. The rate of star birth in the universe increased by ten times during this 170-million-year period, Illingworth said.

"This is an astonishing increase in such a short period, just 1 percent of the current age of the universe," he said.

There were also striking changes in the numbers of galaxies detected. "Our previous searches had found 47 galaxies at somewhat later times when the universe was about 650 million years old. However, we could only find one galaxy candidate just 170 million years earlier," Illingworth said. "The universe was changing very quickly in a short amount of time."

According to Bouwens, these findings are consistent with the hierarchical picture of galaxy formation, in which galaxies grew and merged under the gravitational influence of dark matter. "We see a very rapid build-up of galaxies around this time," he said. "For the first time now, we can make realistic statements about how the galaxy population changed during this period and provide meaningful constraints for models of galaxy formation."

Astronomers gauge the distance of an object from its redshift, a measure of how much the expansion of space has stretched the light from the object to longer ("redder") wavelengths. The newly detected galaxy has a likely redshift value ("z") of 10.3, which corresponds to an object that emitted the light now reaching us 13.2 billion years ago, just 480 million years after the birth of the universe.

"This result is on the edge of our capabilities, but we spent months doing tests to confirm it, so we now feel pretty confident," Illingworth said.

The galaxy, a faint smudge of starlight in the Hubble images, is tiny compared to the massive galaxies seen in the local universe. Our own Milky Way, for example, is more than 100 times larger.

The researchers also described three other galaxies with redshifts greater than 8.2, which was previously the highest confirmed redshift for any object in the universe. The study involved a thorough search of data collected from deep imaging of the Hubble Ultra-Deep Field (HUDF), a small patch of sky about one-tenth the size of the moon. During two four-day stretches in summer 2009 and summer 2010, Hubble focused on one tiny spot in the HUDF for a total exposure of 87 hours with the WFC3 infrared camera.

To go beyond redshift 10, astronomers will have to wait for Hubble's successor, the James Webb Space Telescope (JWST), which NASA plans to launch later this decade. JWST will also be able to perform the spectroscopic measurements needed to confirm the reported galaxy at redshift 10.3.

"It's going to take JWST to do more work at higher redshifts. This study at least tells us that there are objects around at redshift 10 and that the first galaxies must have formed earlier than that," Illingworth said.

Illingworth's team maintains the First Galaxies web site, with information about the latest research on distant galaxies.

###In addition to Bouwens and Illingworth, the coauthors of the Nature paper include Ivo Labbe of Carnegie Observatories; Pascal Oesch of UCSC and the Institute for Astronomy in Zurich; Michele Trenti of the University of Colorado; Marcella Carollo of the Institute for Astronomy; Pieter van Dokkum of Yale University; Marijn Franx of Leiden University; Massimo Stiavelli and Larry Bradley of the Space Telescope Science Institute; and Valentino Gonzalez and Daniel Magee of UC Santa Cruz.

This research was supported by NASA and the Swiss National Science Foundation.

ELSE PRESS RELEASES FROM THIS DATE:

Genome analysis outlines variations in orangutans of Borneo, Sumatra

2011-01-27

HOUSTON -- (Jan. 27, 2011) – In the forests of Borneo and Sumatra, orangutans – the "men of the forest" in the language of Malaysia–swing among the trees, an endangered primate population so similar and yet different from man – and from each other, according to a recently published genome analysis of the two populations of orangutans still existing in the world. The multi-national study led by scientists from Baylor College of Medicine (www.bcm.edu) and Washington University in St. Louis, Mo., define many of the similarities between the two populations – one in Sumatra ...

The cryptic African wolf: Canis aureus lupaster is not a golden jackal

2011-01-27

New molecular evidence reveals a new species of grey wolf living in Africa. Formerly confused with golden jackals, and thought to be an Egyptian subspecies of jackal, the new African wolf shows that members of the grey wolf lineage reached Africa about 3 million years ago, before they spread throughout the northern hemisphere. As long ago as 1880 the great evolutionary biologist Thomas Huxley commented that Egyptian golden jackals – then as now regarded as a subspecies of the golden jackal – looked suspiciously like grey wolves. The same observation was made by several ...

Racial stereotyping found in US death certificates

2011-01-27

Death by homicide, the victim is probably black. By cirrhosis, the decedent is likely Native American. These stereotypes have small but clear effects on the racial classifications used to calculate official vital statistics, according to a new study by sociologists at the University of Oregon and University of California, Irvine. When coroners, medical examiners or funeral directors across the United States fill out death certificates, it appears the racial classifications they make are influenced by the decedent's cause of death in ways that reflect long-running stereotypes ...

Eating poorly can make us depressed

2011-01-27

Researchers from the universities of Navarra and Las Palmas de Gran Canaria have demonstrated that the ingestion of trans-fats and saturated fats increase the risk of suffering depression, and that olive oil, on the other hand, protects against this mental illness. They have confirmed this after studying 12,059 SUN Project volunteers over the course of six years; the volunteers had their diet, lifestyle and ailments analyzed at the beginning of the project, over its course and at the end of the project. In this way the researchers confirmed that despite the fact that ...

Scripps Research study shows map of brain connectivity changes during development

2011-01-27

LA JOLLA, CA – January 24, 2010 – Embargoed by the journal Neuron until January 26, 2010, noon, Eastern time – Connected highways of nerve cells carry information to and from different areas of the brain and the rest of the nervous system. Scientists are trying to draw a complete atlas of these connections—sometimes referred to as the "connectome"—to gain a better understanding of how the brain functions in health and disease. New research conducted at The Scripps Research Institute shows that this road atlas undergoes constant revisions as the brain of a young animal ...

Female lizard turns the table: Why exaggerated coloration makes her a good mate

2011-01-27

Most nature lovers know that the more colourful a male fish, reptile, or bird, the more likely it is to attract a female and to have healthy offspring. Females, on the other hand, tend to be drably coloured, perhaps to avoid predators while carrying, incubating, and caring for young. Curiously, the female striped plateau lizard, which lives in the rocky slopes of Arizona's south-eastern mountains, is an exception to this rule in the animal world. Females are more colourful than males – displaying an orange patch on their throats during reproductive season – and the more ...

Ancient body clock discovered that helps to keep all living things on time

2011-01-27

The mechanism that controls the internal 24-hour clock of all forms of life from human cells to algae has been identified by scientists. Not only does the research provide important insight into health-related problems linked to individuals with disrupted clocks – such as pilots and shift workers – it also indicates that the 24-hour circadian clock found in human cells is the same as that found in algae and dates back millions of years to early life on Earth. Two new studies out today in the journal Nature from the Universities of Cambridge and Edinburgh give insight ...

If you knew Susie -- the sequence of the orangutan genome

2011-01-27

The direct ancestors of orang-utans were once widely distributed in south-east Asia but the two modern orang-utan species are confined to the islands of Sumatra and Borneo. Both species are endangered, largely as a consequence of destruction of their rainforest habitat. The orang-utans are the only great apes that spend most of their time in trees. Nevertheless, the species share a number of features with other apes: they are adept in their use of tools and live in complex social groups that show evidence of cultural learning. A wide-ranging international consortium ...

Casualties of war: Wounded veterans more likely to die of coronary heart disease

2011-01-27

War-time stress may lead to an increased risk death by coronary heart disease in later life. Researchers writing in BioMed Central's open access journal BMC Health Services Research surveyed a cohort of 55 year old Finnish WW2 veterans in 1980, and then carried out a follow-up study 28 years later. Dr Seppo Nikkari and his team from the University of Tampere in Finland conducted the study. He said "During the 28 year follow up , out of 412 deaths, 140 were due to coronary heart disease (CHD), making wounded veterans 1.7 times more likely to die from CHD than the comparison ...

UT Southwestern researchers uncover potential 'cure' for type 1 diabetes

2011-01-27

DALLAS – Jan. 26, 2011 – Type 1 diabetes could be converted to an asymptomatic, non-insulin-dependent disorder by eliminating the actions of a specific hormone, new findings by UT Southwestern Medical Center researchers suggest. These findings in mice show that insulin becomes completely superfluous and its absence does not cause diabetes or any other abnormality when the actions of glucagon are suppressed. Glucagon, a hormone produced by the pancreas, prevents low blood sugar levels in healthy individuals. It causes high blood sugar in people with type 1 diabetes. "We've ...

Astronomers find most distant galaxy candidate yet seen

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: