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Young galaxies are 13-billion light years from home
Jan 10th
DEVELOPING GALAXY CLUSTER EVER FOUND
A team of researchers led by the University of Colorado Boulder has used NASA’s Hubble Space Telescope to uncover a cluster of galaxies in the initial stages of construction — the most distant such grouping ever observed in the early universe.
In a random sky survey made in near-infrared light, Hubble spied five small galaxies clustered together 13.1 billion light-years away. They are among the brightest galaxies at that epoch and very young, living just 600 million years after the universe’s birth in the Big Bang. One light-year is about 6 trillion miles.
Galaxy clusters are the largest structures in the universe, comprising hundreds to thousands of galaxies bound together by gravity. The developing cluster, or protocluster, presumably will grow into one of today’s massive galactic “cities” comparable to the nearby Virgo cluster, a collection of more than 2,000 galaxies.
The composite image at right, taken in visible and near-infrared light, reveals the location of five tiny galaxies clustered together 13.1 billion light-years away. The circles pinpoint the galaxies. The Wide Field Camera 3 aboard NASA’s Hubble Space Telescope spied the galaxies in a random sky survey. The developing cluster is the most distant ever observed. The young galaxies lived just 600 million years after the universe’s birth in the Big Bang. The average distance between them is comparable to that of the galaxies in the Local Group, consisting of two large spiral galaxies, the Milky Way and Andromeda, and a few dozen small dwarf galaxies. The close-up images at right, taken in near-infrared light, show the puny galaxies. The letters “a” through “e” correspond to the galaxies’ location in the wide-field view at left. Simulations show that the galaxies will eventually merge and form the brightest central galaxy in the cluster, a giant elliptical similar to the Virgo cluster’s M87. Galaxy clusters are the largest structures in the universe, comprising hundreds to thousands of galaxies bound together by gravity. The developing cluster presumably will grow into a massive galactic city, similar in size to the nearby Virgo cluster, a collection of more than 2,000 galaxies. Credit: NASA, ESA, M. Trenti (University of Colorado Boulder and Institute of Astronomy, University of Cambridge, U.K.), L. Bradley (Space Telescope Science Institute, Baltimore), and the BoRG team
or more information on the galaxies visit the news center at http://hubblesite.org/.
“These galaxies formed during the earliest stages of galaxy assembly, when galaxies had just started to cluster together,” says the study’s leader, Michele Trenti, a research associate at CU-Boulder’s Center for Astrophysics and Space Astronomy and a newly appointed scientist at the Institute of Astronomy at the University of Cambridge in the United Kingdom. “The result confirms our theoretical understanding of the buildup of galaxy clusters. And Hubble is just powerful enough to find the first examples of them at this distance.”
Trenti will present his results Jan. 10 at the American Astronomical Society meeting in Austin, Texas. The study will appear in the Feb. 10 issue of The Astrophysical Journal.
Most galaxies in the universe live in groups and clusters, and astronomers have probed many mature “galactic cities” in detail as far as 11 billion light-years away. But finding clusters in the early phases of construction has been challenging because they are rare, dim and widely scattered across the sky.
“Records are always exciting, and this is the earliest and the most distant developing galaxy cluster that has ever been seen,” said CU-Boulder Professor Michael Shull of the astrophysical and planetary sciences department, a member of the observing team. “We have seen individual galaxies this old and far away, but we have not seen groups of them in the construction process before.”
Last year, a group of astronomers uncovered one distant developing cluster. Led by Peter L. Capak of NASA’s Spitzer Science Center at the California Institute of Technology in Pasadena, the astronomers discovered a galactic grouping 12.6 billion light-years away with a variety of telescopes, including Hubble. Spectroscopic observations were made with the W.M. Keck Observatory in Hawaii to confirm the cluster’s distance by measuring how much its light has been stretched by the expansion of space.
Trenti’s team used the sharp-eyed Wide Field Camera 3 to hunt for the elusive catch. “We need to look in many different areas because the odds of finding something this rare are very small,” Trenti said. “It’s like playing a game of Battleship: The search is hit and miss. Typically a region has nothing, but if we hit the right spot we can find multiple galaxies.”
Because these distant, fledgling clusters are so dim, the team hunted for the systems’ brightest galaxies. These bright lights act as billboards, advertising cluster construction zones, according to the team. Galaxies at early epochs don’t live alone. From simulations, the astronomers expect galaxies to be clustered together.
Because brightness correlates with mass, the most luminous galaxies pinpoint the location of developing clusters. These powerful light beacons live in deep wells of dark matter, which form the underlying structure in which galaxy clusters form, Trenti said. The team expects many fainter galaxies that were not seen in these observations to inhabit the same neighborhood.
The five bright galaxies spotted by Hubble are about one-half to one-tenth the size of our Milky Way, yet are comparable in brightness. The galaxies are bright and massive because they are being fed lots of gas through mergers with other galaxies, Trenti said. The team’s simulations show that the galaxies will eventually merge and form the brightest central galaxy in the cluster, a giant elliptical similar to the Virgo Cluster’s M87.
The observations demonstrate the progressive buildup of galaxies and provide further support for the hierarchical model of galaxy assembly, in which small objects accrete mass, or merge, to form bigger objects over a smooth and steady but dramatic process of collision and agglomeration. Astronomers have likened the process to streams merging into tributaries, then into rivers and to a bay.
Hubble looked in near-infrared light because ultraviolet and visible light from distant objects have been stretched into near-infrared wavelengths by the expansion of space in these extremely distant galaxies. The observations are part of the Brightest of Reionizing Galaxies or BoRG survey, which is using Hubble’s Wide Field Camera 3 to search for the brightest galaxies around 13 billion years ago, when light from the first stars burned off a fog of cold hydrogen in a process called reionization.
The team estimated the distance to the newly spied galaxies based on their colors, but the astronomers plan to follow up with spectroscopic observations to confirm their distance.
Without spectroscopic observations, it’s not clear whether the observed galaxies are gravitationally bound yet. The average distance between them is likely comparable to that of the galaxies in the Local Group, consisting of two large spiral galaxies, the Milky Way and Andromeda, and a few dozen small dwarf galaxies.
These observations are pushing Hubble to the limit of its ability. This region, however, will be prime country for future telescopes such as NASA’s James Webb Space Telescope, an infrared observatory scheduled to launch later this decade. Webb will see farther into the infrared, allowing it to hunt for even earlier stages of galaxy assembly within 300 million years of the Big Bang.
Shull, also a faculty member at CU-Boulder’s Center for Astrophysics and Space Astronomy, said the research team will receive an additional 260 orbits of observation time on Hubble to continue the search for more of the fledgling galaxy clusters as part of the BoRG survey. “There is high interest right now in learning if Earth is unique in the universe in its ability to host life,” he said. “Similarly, we are interested to see if these ancient, forming galaxy clusters we have identified are unique, or if there are others out there. I expect that we may find a few more.”
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute, or STScI, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy Inc., in Washington, D.C.
For more information on the galaxies visit the news center at http://hubblesite.org/. For more information on CU-Boulder’s CASA visit http://casa.colorado.edu/.
For more information on CU-Boulder’s CASA visit http://casa.colorado.edu/.
CU team to turn on “green” lights in Haiti
Jan 5th
CU ENGINEERING TEAM TO SUPPORT
GREEN ENERGY IN HAITI
A team of University of Colorado Boulder engineers will travel to Haiti this month to support the growth of green energy on the two-year anniversary of the country’s devastating earthquake.
Engineering professors Alan Mickelson and Mike Hannigan and graduate student Matt Hulse will be in Haiti Jan. 8-16 to collaborate with the Neges Foundation school at Leogane to create a vocational training program on the installation, operation and maintenance of renewable energy systems.
“I’m eager to learn about the people of Haiti and the services that they would like energy systems to provide,” said Hannigan, an assistant professor of mechanical engineering. “Historically, the development of energy systems has shaped nations and economies, so the timing is right to pass along what we have learned about those energy systems that are sustainable.”
The Jan. 12, 2010, earthquake that struck Haiti destroyed what little electricity infrastructure had existed in the country, plunging towns across the country into total darkness and forcing households to rely on high-cost diesel generators for power, according to news reports. As a result, families are unable to study or work at night, and the number of assaults, particularly against women and girls, has increased.
Studies point to Haiti’s great potential for renewable energy, including solar, hydro and wind power. “The present lack of a Haitian power grid cries out for a distributed solution — that is, one that grows from small, localized, renewable energy sources,” said Mickelson, associate professor of electrical, computer and energy engineering.
To address these issues, the Engineering for Developing Communities project will:
- Develop a curriculum for vocational training on the operation and maintenance of self-contained, adaptable power sources, and electrical operations and maintenance with a focus on green energy systems.
- Build local capacity to provide vocational training on renewable energy systems using a “train-the-trainers” approach.
- Identify a viable system to create sustainable access to renewable energy that will meet basic household energy needs.
- Develop a strategy for the sustainable scale-up and replication of energy and infrastructure vocational training to support reconstruction efforts, with a focus on private sector investment.
About $35,000 has been provided for the initiative by CU-Boulder’s Mortenson Center for Engineering in Developing Communities, the IEEE Foundation and the CU-Boulder Outreach Committee. The Mortenson Center is seeking additional funding to build upon the initiative and develop additional vocational training curriculum on sustainable and disaster-resistant design and construction.
The Mortenson Center was founded to promote integrated, participatory and sustainable solutions to the engineering challenges of the developing world, with a focus on clean drinking water, sanitation and hygiene; energy; sustainable and disaster-resistant building materials and shelter; and cook stoves and indoor air quality. For more information, go tohttp://ceae.colorado.edu/mc-edc.
Boulder police release photos of suspect in robbery
Dec 23rd
The suspect in yesterday’s robbery of Great Western Bank on Pearl St. remains at large, and Boulder police are releasing the attached photos of the suspect in the hopes that members of the public might recognize him or his clothing.
The robbery happened around 10:30 Thursday morning, Dec. 22, 2011. The suspect entered the bank, approached the teller and demanded cash. The teller cooperated and the suspect left the bank on foot with an undisclosed amount of cash. No one was hurt and no weapon was used.
Most of the suspect’s face was covered in white, gauze-like bandages, which were taped with “dirty,” white medical tape. The area around his right eye was exposed, and witnesses believe he is a white male. He is described as:
- 5’6” – 5’7” tall
- 180 pounds
- 25 – 30 years old
- Wearing blue jeans, boots, a black hoodie and a teal-colored ski-type jacket over the hoodie
- Teal-colored knit beanie cap, with some sort of logo or writing on it
Another branch of Great Western Bank, located at 1900 9th St., was robbed Friday, Dec. 16, 2011. The suspect in that case also got away with an undisclosed amount of cash, and he is still at large. Investigators do not know yet whether the two robberies are related.
The case number is 11-16507.
Anyone with information about either robbery is asked to contact the Boulder Police Department’s Tip Line at 303-441-1974. Those who have information but wish to remain anonymous may contact the Northern Colorado Crime Stoppers at 1-800-222-TIPS (8477) or 1-800-444-3776. Tips can also be submitted through the Crime Stoppers website at www.crimeshurt.com. Those submitting tips through Crime Stoppers that lead to the arrest and filing of charges on a suspect(s) may be eligible for a cash reward of up to $1,000 from Crime Stoppers.