April 13, 2012
UCLA’s “Time Machine” To Study Distant Galaxies
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A team of researchers at the University of California, Los Angeles (UCLA) are building an advanced scientific instrument unlike any other ever built before, with the aim to study some of the oldest galaxies in the universe.The five-ton spectrometer, known as MOSFIRE (Multi-Object Spectrometer for Infra-Red Exploration), has been installed in the Keck I Telescope at the WM Keck Observatory in Hawaii where, once fully operational, it will receive infrared light that is collected by the telescope. MOSFIRE will then be able to sift through the cosmic dust and see distant objects whose light has been red-shifted as a result of the universe´s ongoing expansion.
Ian McLean, lead researcher on the project, and director of UCLA´s Infrared Laboratory for Astrophysics, said the “time machine” -- as it is being dubbed -- will allow researchers to study “the most distant, faintest galaxies,” some of which are close to 10 billion years old, being formed just a few billion years after the Big Bang.
“When we look at the most distant galaxies, we see them not as they are now but as they were when the light left them that is just now arriving here,” he added. “We are looking back in time to the era of the formation of some of the very first galaxies, which are small and very faint. That is an era that we need to study if we are going to understand the large-scale structure of the universe.”
With MOSFIRE, it will be much easier to identify even the faintest of galaxies in the universe. The instrument will also enable McLean and his colleagues to attain a more detailed picture of the formation of stars within our own galaxy, the distribution of dark matter across the universe, and merging galaxies, as well as other phenomena.
“We would like to study the environment of those early galaxies,” said McLean. “Sometimes there are large clusters with thousands of galaxies, sometimes small clusters. Often, black holes formed in the centers of galaxies.”
MOSFIRE, a collaborative effort between colleagues from UCLA, the California Institute of Technology and UC Santa Cruz, along with industrial sub-contractors, is the latest in a series of similar projects focusing on deep space analysis. The seven-year, federally-funded, $14 million initiative got its first hint of life on April 4th, when light from the Keck I Telescope was fed into MOSFIRE for the first time, resulting in an image of two galaxies colliding. The system is expected to be fully operational by September.
MOSFIRE will allow astronomers to study up to 46 galaxies simultaneously, providing the infrared spectrum for each galaxy. Currently, it can take three hours or longer to obtain a good spectrum of just one galaxy, McLean noted.
While construction of the MOSFIRE instrument was undertaken by several colleagues at different locations, the bulk of the mechanical parts were built at UCLA and Caltech. However, the slit unit that enables the team to study 46 galaxies at a time was manufactured in Switzerland. The computer programming was led by UCLA researchers.
MOSFIRE was federally funded by the National Science Foundation (through the Telescope System Instrumentation program), and by Gordon and Betty Moore. Gordon Moore is co-founder, former chairman and chief executive officer, and chairman emeritus of Intel Corp.
“He is a wonderful man with a penetrating intellect,” McLean said of Moore. “We are deeply indebted to him and hope to be able to show him MOSFIRE this.”
MOSFIRE is not McLean´s first project. In the late 1990s he delivered an infrared spectrometer known as NIRSPEC to the Keck Observatory in Hawaii, which housed the world´s largest optical and infrared telescope at the time and which contains what had been the most powerful infrared spectrometer in the world. NIRSPEC is still in use at the Keck Observatory, currently installed on the Keck II Telescope.
The MOSFIRE instrument is approximately five times more sensitive than NIRSPEC and about 100 times more sensitive than McLean´s earliest infrared cameras built in 1986.
Use of the NIRSPEC instrument resulted in severable notable discoveries, including the detection of water on comets, insights into the stars orbiting the enormous black hole at the center of our galaxy, and the discovery of the chemical makeup of brown dwarf stars.
MOSFIRE should far exceed NIRSPEC´s capabilities when it goes fully live in September.
Image Caption: One of the first infrared pictures from MOSFIRE on the Keck I Telescope showing two galaxies in collision: NGC4038 (upper) and NGC4039. Also known as the Antennae galaxies, these objects are about 45 million light years away, in the constellation of Corvus. The exposure was a brief 60 seconds under cloudy conditions. Image credit: Ian S. McLean/W.M. Keck Observatory