Instrument The Gemini North Telescope on Mauna Kea has a new instrument allowing astronomers to see details in galaxies "as if they were our close neighbors," says the instrument team leader.
casts sharper eye
on galaxy
The new addition at a Big Isle
observatory helps scientists
study details in the universeBy Helen Altonn
haltonn@starbulletin.comRoger Davies of Durham University in England said the new $5 million Gemini Multi-Object Spectrograph "is going to keep astronomers very busy and extremely happy for a long time."
It will produce data on galaxies allowing scientists to determine "their mass, size and composition and look back in time to see how they have changed through cosmic history," he said.
Bob Abraham of the University of Toronto said the new spectrograph "is a dream instrument on a dream telescope."
After seven years of design and construction and only two weeks in use on the Gemini 8.1-meter telescope, a first light image was obtained of "the Perfect Spiral Galaxy."
Commissioning of such an instrument usually is a long drawn-out process, said Peter Michaud, Gemini spokesman.
"This went incredibly smoothly. To get an image right off the bat like this is really thrilling to us," he said.
The first light image is of a large galaxy in Pisces called NGC 628 or Messler 74, about 30 million light years away, Michaud said.
"It shows a remarkable amount of detail, considering how far away it is."
He said it is a classic example of a spiral galaxy, similar to the Earth's Milky Way.Gemini North's Associate Director Jean-Rene Roy said, "To be able to routinely see fine details in a galaxy more than 30 million light years away is quite remarkable and helps to give some perspective of what our own galaxy might look like if there were another Gemini-sized telescope looking back at us."
The NGC 628 galaxy contains an estimated 100 billion stars, making it slightly smaller than the Milky Way, the scientists said.
Michaud said the first light image is not typical of what the Gemini Multi-Object Spectrograph will do. It can focus on astronomical images with an array of more than 28 million ultra-sensitive pixels. But it is designed to get spectra from many parts of the galaxy at one time, he said.
The data allow astronomers to determine the chemical composition, pressures and velocities of whatever they're looking at so a lot of investigative work can be done on an object, Michaud said.
Dr. Matt Mountain, Gemini Observatory director, said, "This instrument took world-class data on its first night on the sky performing perfectly, right out of the box, or at least the 24 crates that brought the two-ton instrument to Hawaii from Canada and the United Kingdom."
The instrument was built by Gemini, Canada and the United Kingdom, with a detector subsystem and software provided by the U.S. National Optical Astronomy Observatory.
Gemini's seven international partners will begin using the spectrograph for scientific studies later this year.
Gemini astronomer Inger Jorgensen, who led the commissioning project, said, "I'm most interested in the planned observations of distant galaxy clusters where Gemini is able to work like a time machine and look back in time to study a much younger universe than we see around us today."
"One area where I think this instrument will excel is the study of supernova, or exploding stars in very distant galaxies," said Isobel Hook of the United Kingdom, who helped obtain the first image. "Once we can obtain spectra from these stars, we will be able to better understand the apparent acceleration of the universe."
The Gemini Observatory collaboration has two identical 8.1-meter telescopes.
The other is Gemini South, Cerro Pachon in central Chile, expected to begin scientific operations late this year.