When in 2023 Vera c. When the Rubin Observatory begins observation, its SUV-shaped camera will be able to capture a full panorama of the southern sky every few nights. And this requires a new type of camera never seen before.
The imaging sensor for the world’s largest digital camera has captured 3,200 megapixel images for the first time by teams at the Department of Energy’s SLAC National Accelerator Laboratory (originally the Stanford Linear Accelerator Center) in California.
Once this array of sensors is installed in the camera at SLAC and transported to the Rubin Observatory in Chile, it will contribute to the observatory’s 10-year legacy survey of space and time.
The survey will serve as a list of billions of galaxies and celestial bodies, which will essentially make “the greatest astronomical film of all time” and unlock the mysteries of the universe.
The first 3,200-megapixel images captured using the sensor are so stretched that they would require a 378 4K ultra-high-definition TV screen to display only one of them at its full size.
The assembly of the sensor in the camera’s focal plane was completed in January, and the first images were used to test it.
“The focal plane will produce images for the LSTS, so it is the capable and sensitive eye of the Rubin Observatory,” Vincent Riot, LSTS camera project manager, said in a statement. The riot is from Lawrence Livermore National Laboratory, California.
The focal plane of the camera, similar to an imaging sensor in a digital camera, includes 189 sensors that provide 16 megapixels each. And it is 2 feet wider than the usual 1.4 inch wide sensor in digital full-frame cameras.
This makes the sensor large enough to image a part of the sky that is equivalent to 40 full moons.
The observatory’s capabilities enable it to blur faded objects 100 million times that we can see with the naked eye. It is designed to map the Milky Way, detect dark energy and dark matter, and survey the solar system.
During the 10-year survey, the camera is expected to image 20 billion galaxies.
“These data will improve our knowledge of how galaxies have evolved over time and allow us to test our models of dark matter and dark energy more deeply and accurately than ever before,” project scientist at LSTS Camera, University of California Steven Ritz said. , Santa Cruz, in a statement.
“The observatory will be an amazing facility for a wide range of science – from detailed studies of our solar system to studying objects on the edge of the cosmos that are visible from the distant universe.”
Capturing first images
Before the LSST camera could point its eye towards the sky, it had to undergo a delicate assembly along with the test.
The focal plane took six months to assemble. Each grid of nine sensors is called a scientific fleet, and 25 rafts had to be fitted in their spots along the grid. If they come in contact with each other, the sensors can easily burst, and they only have a small gap between the rafts – less than five human hairs wide.
And the raft costs around $ 3 million. This explains why the team took a year to prepare before starting any raft.
The focal plane itself is inside a cryostat, a device that holds the sensor at a cool negative 150 degrees Fahrenheit, the temperature they need to operate.
Although the assembly of the focal plane was completed in January, the coronovirus epidemic kept the team from reaching the lab to take the first images using the focal plane in May – and yet, with limited staff and social disturbances in place.
While the focal plane continues to test, the first pictures are a huge milestone.
Although the camera itself is not fully assembled, the team was able to use a 150-micron pinhole that served as the focal plane’s projector to take some preliminary pictures.
The first images include a Romanesco vegetable, which was chosen for its elaborate surface, along with Vera Rubin herself, who is named for the observatory.
Rubin, who died in 2016, once mentioned fellow aspiring female astronomers and advocated for women in science. It is true that the first National American Observatory named for a female astronomer is in her honor. Considered one of the most influential female astronomers, Rubin first provided some evidence that Dark Matter – which covers much of the universe, but cannot be seen – existed.
New images have shown how much the sensors can expand.
“Taking these pictures is a major achievement,” SLAC professor and chairman of the Department of Particle Physics and Astrophysics said to the SLAC scientist responsible for the assembly and testing of SLAC in a statement.
“With tight specifications, we really pushed the limits of what is possible to take advantage of each square millimeter of the focal plane and maximize the science we can do with it.”
Next comes the camera assembly: the focal plane and cryostat are inserted into the camera body, connecting the world’s largest optical lens, shutter and filter exchange system.
The team speculated that the camera would be ready for testing by mid-2021 before leaving for Chile.
“This is a milestone that brings us a big step closer to exploring fundamental questions about the universe that we haven’t been able to before,” Joan Hewett, SLAC’s chief research officer and associate lab director of fundamental physics Said in a statement. .