Large Synoptic Survey Telescope will revamp astronomy playing stage


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Photo by Michelle Klejmont |

The Large Synoptic Survey Telescope (LSST), is a new telescope built by an international team of scientists that will scan the universe with unprecedent width, depth and speed and capture high-resolution images of the universe. MICHELLE KLEJMONT / MANAGING EDITOR


A new telescope built by an international team of scientists will soon take high-resolution images of the universe.

The Large Synoptic Survey Telescope will scan the universe with unprecedented width, depth and speed, said Charles Keeton, an associate professor in the Department of Physics and Astronomy, who is helping design and construct the device.

Once finished, the telescope will assist enormously in astronomical researches such as his cosmic telescope research through Aresty Research program, he said. The LSST is under construction in Chile, where it has been in design for about 15 years, and is expected to start its operations within the next decade.

“It’s a new approach to astronomy,” he said, “Over the course of 10 years, starting (in) 2022, it will send us the movie of the sky.”

Chile is an ideal site for the telescope set up because of its climate conditions, infrastructure and government support, Keeton said.

The country is located at a higher altitude and is relatively dry, which are important traits for astronomers, he said. They look for higher altitudes because getting above some of the atmosphere limits the blur it causes on images.

Chile has attracted a number of astronomers together with the construction of observatories over the past decades, Keeton said. The Chilean government also recognizes the importance of astronomy.

“They see astronomy as a way for this nation to contribute to international science,” Keeton said.

Keeton said historically astronomers have proceeded largely by studying individual objects. In the past decades their focus shifted to survey science, where astronomers look at a large area of the sky.

The digital sky survey pioneers this approach, but for most of the digital catalogs of the sky, they only observe an object once, he said.

“If you want to look at how things change over time, you’ll need to look over and over again,” Keeton said.

The LSST observes objects repeatedly, thus yielding a movie of the sky and showing the variability of the objects it observes, he said.

This method of observation will gather far more data than previous ones, "revolutionizing" how astronomers work, he said.

According to the LSST website, with a 3200 Megapixel camera as the centerpiece, the telescope will be able to image faint astronomical objects across the sky.

“Instruments such as the Hubble space telescope have been incredibly valuable for looking at individual objects, since it only looks at a small area of the sky,” Keeton said.

According to the SLAC National Accelerator Laboratory, another partner leading the LSST construction, the digital camera will be the largest ever built, allowing the LSST to create an unprecedented archive of astronomical data.

The University joins the LSST project as an institutional partner, Keeton said.

“(The University's participation) gives us the ability to participate in this design and development phase of the project. There are details of the observation that are still being ironed out,” Keeton said.

The telescope will facilitate answering science questions, from distant galaxies to stars in our own galaxy, and even asteroids that might actually post a threat to Earth, Keeton said.

That is just one potential use for the LSST, he said. The goal is to create a versatile machine that can fulfill different purposes.

The data generated by LSST will also be of enormous help to Keeton’s research on gravitational lensing: the bending of light by gravity, he said.

Gravitational lensing can be used to help understand how dark matter interacts with the universe, said Jaclyn Champagne-Bradli, a School of Arts and Sciences junior in an email.

Finding cosmic telescopes — for clusters of galaxies whose gravitational influence bends light — is one goal for Keeton's research, he said.

“Objects that are behind those clusters of galaxies (have) their light ... distorted and magnified,” he said. “In the same way, we use a telescope to peer out into space as natural light and bend light even further.”

The goal of the gravitational lensing project is to understand how these galaxies clusters actually bend light, Keeton said. If the light has been distorted and magnified by the intervening clusters, Keeton’s team seeks to counter that effect in order to know what the source really looks like.

Gravitational lensing is used to help see objects that would otherwise be invisible, but its effects must be removed to properly see the source, he said.

The team first did a theoretical study in order to figure out what would be the best combination of galaxy clusters — the most powerful cosmic telescopes — for magnifying distant galaxies, he said.

It is likely dark matter is responsible for bending light, Champagne-Bradli said. By analyzing how the light is bent, researchers can determine what dark matter looks like and how mass near and between galaxies is distributed.

Students from the Aresty program help the project by calibrating or focusing, these cosmic telescopes.

Christine Ray, a junior in the Department of Physics and Astronomy, said she was looking for the most powerful gravitational lenses.

“We can have individual galaxies joining together forming a galaxy cluster, and even then you can have even larger structures such as multiple galaxy clusters along the single line," she said.

Ray builds models to understand the mass distribution within the clusters, she said. Understanding mass distribution makes it possible to calculate how light bends.

From there the team uses it to understand how these cosmic telescopes are distorting the view of the background, she said.

“We already identified two systems that have multiple galaxy clusters. What we are doing is modeling them,” she said. “What I’m doing is (testing) those models and (trying) to figure out which one is creating the images that we are seeing.”


Weini Zhang

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