The South Pole Telescope – Extreme astronomy unlocks cosmic secrets

The South Pole Telescope - Extreme astronomy unlocks cosmic secrets
The South Pole Telescope - Extreme astronomy unlocks cosmic secrets

Extreme astronomy unlocks cosmic secrets from the South Pole – The South Pole Telescope is perfectly located to gaze deep into the universe, but it takes a hardy group of astronomers to live there over the winter.

______

Imagine doing astronomy where grease won’t stay greasy, where it’s nighttime all day during the winter, and where nighttime temperatures fall to -100 Fahrenheit. Well, there’s a hardy group of astronomers that enthusiastically do that, year-in, year-out, at Antarctica’s South Pole Telescope.

The South Pole is a harsh environment, but it’s excellent for astronomy due to its dry atmosphere (water vapor interferes with observations). Researchers at the Harvard Smithsonian Center for Astrophysics are even considering building a telescope at a site called Dome A, about 1,000 miles from the pole and a long trek from habitation.

What is it really like to work down there for up to a year, which is the typical over-winter stay of Antarctic personnel? According to University of Toronto experimental cosmologist Keith Vanderlinde, who spent 11 months there over the winter, it attracts a certain type of person who doesn’t necessarily need the company of other people to work well. His group vacillated between being super-social in shared quarters, and choosing to retreat individually to their own quarters. He also saw people “going toasty” (this Antarctic slang for changed behavior comes from bread turning into toast) as they grappled with months of isolation away from families.

“People who didn’t work outside at all, they got toasty very quickly. You develop a short fuse,” Vanderlinde told Seeker. “People develop a 1,000-mile stare and stare at the wall for an hour and not do anything.”

Vanderlinde came to the National Science Foundation-funded South Pole Telescope in 2008 after his Ph.D., when the facility was just in its second year of operations. It was a half-hour trek from the living quarters to the telescope, where Vanderlinde and a colleague checked in to make sure the telescope was staying healthy. Overall the work went well, except for occasional mechanical issues. He recalled, for example, one time when the power went out on a Sunday night, which required a long warm-up procedure that Monday to get the telescope up and running again.

The conditions are harsh, but Vanderlinde says the science is worth it. The telescope is mapping out the cosmic microwave background (CMB), which is the leftover energy from when the universe was first expanding. It can best be seen in microwave wavelengths. As the CMB shines through galaxy clusters, Vanderlinde says, some light scatters off hot electrons and can show up as an excess of energy.

“By looking at these little shadows, you can figure out where all of the largest structures in the universe are,” he said. Over time and with observations from the South Pole Telescope’s first camera, he said, scientists can also learn how galaxy clusters grew in different eras of the universe, and how dark energy — the ill-understood force that is causing the universe’s expansion to accelerate — works.

The second-generation camera on the South Pole Telescope measures the intensity of the light and polarization, or how light is oriented related to the direction where it came from. As the CMB is lensed through galaxies and other structures, scientists can measure how large clumps of matter form over time, which in turn tells them how gravity works. Oddly, he said, tiny particles called neutrinos significantly impact how structure forms in the universe, and how gravity pulls gas and dust together into clusters and galaxies. So by looking at the big scale, scientists can better constrain how massive neutrinos are.

In 2014, another South Pole telescope called BICEP2 detected polarization modes (known as B modes) that were originally interpreted as gravitational waves, or ripples in space-time that form from gravitational interactions. However, further study revealed a more mundane explanation: the polarization came from dust in our own galaxy.

Would Vanderlinde over-winter again? He’s made several summer visits since then, but he said once was enough. “After I left I had recurring nightmares that I went back for another winter,” he said. “It was not in any way a bad experience, but at the end you’re done … and the idea of doing it again didn’t appeal to me.”

Vanderlinde will deliver a public lecture on his experiences later this month in Toronto, Canada. If you can’t make the talk, you can watch a TEDx presentation he gave last year on south pole science, or read his blog from his year in Antarctica.

South Pole Telescope

The South Pole Telescope (SPT) is a 10 meter (394 in) diameter telescope located at the Amundsen–Scott South Pole Station, Antarctica. The telescope is designed for observations in the microwave, millimeter-wave, and submillimeter-waveregions of the electromagnetic spectrum, with the particular design goal of measuring the faint, diffuse emission from thecosmic microwave background (CMB). The first major survey with the SPT–designed to find distant, massive, clusters of galaxies through their interaction with the CMB, with the goal of constraining the dark energy equation of state–was completed in October 2011. In early 2012, a new camera was installed on the SPT with even greater sensitivity and the capability to measure the polarization of incoming light. This camera is designed to measure the so-called “B-mode” or “curl” component of the polarized CMB, leading to constraints on the mass of the neutrino and the energy scale of inflation.

The South Pole Telescope. A picture of the South Pole Telescope collaboration in front of the telescope

The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago, the University of California-Berkeley, Case Western Reserve University, HarvardSmithsonian Astrophysical Observatory, the University of Colorado-Boulder, McGill University, The University of Illinois at Urbana-Champaign, University of California at Davis, Ludwig Maximilian University of Munich, Argonne National Laboratory, and the National Institute for Standards and Technology. It is funded by the National Science Foundation.

___

Online:

http://www.seeker.com/

https://pole.uchicago.edu/

https://en.wikipedia.org/