Tags Posts tagged with "Anže Slosar"

Anže Slosar

By Daniel Dunaief

Monday, June 23, marked the beginning of a new and exciting frontier. Using the largest digital camera ever built for astronomy, the Vera C. Rubin Observatory shared its first images after a journey from conception to reality that lasted over two decades.

Located in the Cerro Pachón mountaintop in Chile because the area is dry, high and dark, the telescope and camera started its 10-year mission to share images of the sky.

Viewers at over 350 watch parties in the United States and around the world awaited these pictures, including with gatherings at Stony Brook University and Brookhaven National Laboratory.

The state-of-the-art camera did not disappoint.

The Rubin Observatory, which can take images with a field of view of the sky that are the equivalent of 40 moons, discovered 2,400 asteroids that no one has ever seen before. And that’s just the tip of the iceberg. By the time the Observatory has collected all the data the public can view, the camera is expected to find over five million asteroids.

“Most of the asteroids are too faint to have been found” with previous technology, said Paul O’Connor, senior physicist at Brookhaven National Laboratory who has been working on the camera since 2002.

Simon Birrer, Assistant Professor in the Department of Physics and Astronomy at Stony Brook University, attended a watch event at the university with some 50 to 60 other excited members of the college community.

“Knowing that the instrument is capable and what it was promised to do and seeing it all coming together, sharing the excitement with so many other people is very exciting,” said Birrer.

By looking at the night sky over the course of just a few days, the observatory was able to offer a time lapse view of the movement of these asteroids.

“You can look and see the trail of thousands of things that are completely new,” said Birrer.

Indeed, in addition to seeing asteroids and other objects both near and far, the Rubin Observatory can study dark matter and dark energy, map the Milky Way, and observe transient events.

“We’re entering a golden age of American science,” Harriet Kung, acting director of the DOE’s Office of Science, said in a statement. “NSF-DOE Rubin Observatory reflects what’s possible when the federal government backs world-class engineers and scientists with the tools to lead.”

The first images generated considerable excitement in the scientific community and on campuses around the world.

“It’s a new frontier for sure,” said O’Connor. “We’ve been working on this project for all these years. It was easy to get students interested.”

Anja von der Linden, Associate Professor in Physics and Astronomy at Stony Brook and a member of the LSST Dark Energy Science Collaboration since its inception in 2012, viewed the images from Germany, where she is visiting her parents on vacation with her young daughter.

She works on clusters of galaxies and was delighted to see the Virgo cluster online.

“The image is so large and [viewers] can also see much more distant galaxies,” said von der Linden. Viewers are able to scroll around and zoom in and out to see details in these “beautiful images.”

Von der Linden echoed the sentiment from one of the officials who shared the first images, suggesting that the data and information from the observatory are available for astronomers and scientists, but also for the public, helping them explore the night sky.

“It’s quite remarkable,” she said. “I look forward to seeing how the public engages.”

The Rubin Observatory will see “everything that changes, explodes, and moves,” said von der Linden.

A little bit of pride

In addition to scientists like O’Connor and Anže Slosar, group leader of the Cosmology & Astrophysics Group, BNL recruited close to two dozen interns to help with the work.

“There’s a lot of inherent curiosity about the cosmos,” O’Connor said. “When people hear that they could participate in doing research that could lead to lead to a better understanding of it, we had to turn interns away.”

O’Connor worked with the charge-coupled device modules, which are the digital film of the camera. The Rubin Observatory, with its 3.2 gigapixel focal plane, relies on 189 custom-designed CCD sensors to achieve its resolution.

“I feel a little bit of pride,” said O’Connor, who didn’t expect to be working on astronomical instruments when he came to BNL. “I was a tiny, little part of a giant team that’s worked so long. When you see the final project, it’s a good feeling.”

Seeing the invisible

At the same time that the Rubin Observatory can find asteroids that had previously gone undetected, it can also help detect dark energy and dark matter.

Only five percent of the universe comes from visible matter, with about 70 percent coming from dark energy and 25 percent coming from dark matter.

Dark energy describes why the universe continues to expand after the Big Bang, rather than slowing down, the way a ball thrown into the air does before it falls, von der Linden explained. Researchers study dark matter, meanwhile, by observing the way light from distant galaxies bends when it travels towards Earth, as the gravitational force of the matter affects it on its path.

Von der Linden said she has already started using some of the commissioning data to test Rubin’s capabilities to do weak gravitational lensing. Weak gravitational lensing involves slight shifts in images caused by the gravitational influence of other matter that require many galaxies to detect.

“The work we’re doing now is very much a test case, which we will then take and apply to a much larger data set,” she said.

Inspiring future scientists

The images and the data, which the US, the UK and France will process, has the potential not only to answer scientific questions, but also to encourage and inspire future researchers.

The Rubin Observatory has a “very comprehensive education and public outreach component,” von der Linden said. “From the beginning, it has been built with the intention that the public is suppose to interact with the data and be part of the scientific story.”

If teachers use this in the classroom to show students the beautiful and intriguing night sky, “I would think this will lead some students to consider pursuing” careers in these sciences. “I hope that we’re going to get more junior scientists who will be part of Rubin.”

To see images from the observatory, visit https://rubinobservatory.org.

Paul O'Connor. Photo by Roger Stoutenburgh/ BNL

By Daniel Dunaief

The Earth is way too noisy.

The far side of the moon, however, can act like enormous noise cancellation headphones, serving as a barrier to the kinds of signals from sources including Earth’s ionosphere, which carries electromagnetic noises from lightning, solar flares, radio signals, among others to look or, perhaps more appropriately, listen deep into the past.

On Wednesday, May 7, at Napper Tandy’s in Smithtown, three Brookhaven National Laboratory scientists will speak with the public about an unnamed mission expected to take off next year. The free event is part of BNL’s PubSci science café series (www.bnl.gov/pubsci/).

Paul O’Connor. Photo by Roger Stoutenburgh/ BNL

Senior Scientist Paul O’Connor, Mechanical Engineer Connie-Rose Deane and Physicist Anže Slosar will discuss a project called LuSEE-Night, which, like so many other efforts at BNL, is an acronym. LuSEE stands for Lunar Surface Electromagnetic Experiment-Night.

The Department of Energy project manager is Sven Hermann at Brookhaven National Laboratory. Slosar is the science lead, while O’Connor coordinated technical and systems aspects of the instrument development.

The scientists collaborated with researchers at the National Aeronautics and Space Administration and the Department of Energy and included scientists at the University of Minnesota and at the University of California, Berkeley.

The Space Science Laboratory at the University of California, Berkeley is leading the project. BNL is a collaborating member responsible for delivering hardware components of the payload.

LuSEE-Night, which is a radio telescope, is designed to gather information about the Dark Ages of the universe. This time period, from about 380,000 to 400 million years ago after the Big Bang, occurred before the first luminous stars and galaxies. 

Connie-Rose Deane. Photo by David Rahner/ BNL

As the only signals measurable from the Dark Ages, radio waves, recorded through LuSEE-Night provide a chance to learn how the first non-luminous matter evolved into stars and galaxies.

Over the last several years, scientists at the Department of Energy and NASA have shared their excitement about seeing something they had never seen before.

David Rapetti, Senior Researcher with Universities Space Research Association (USRA) at NASA’s Ames Research Center in California’s Silicon Valley, suggested the instrument was a “trailblazer for subsequent potential single telescope experiments for the global signal, also including the Cosmic Down signal at a somewhat higher frequency range.”

Rapetti, who has been with the project since its inception, suggested that this instrument could help with plenty of other science.

“In addition to studies of the sun, planets and exoplanets, the roadmap ahead for low frequency observations from the lunar surface represents a crucial resource to further our understanding of the evolution, content and first luminous objects of the early Universe,” Rapetti explained.

A potential measurement of the global Dark Ages signal could in principle reveal “undiscovered new physics or indeed further validate the current standard model of cosmology,” Rapetti added.

Challenging conditions

When looking for a landing site, the team searched for a flat, level surface that was free of large rocks and craters and that had an unobstructed view of the sky in all directions.

Anže Slosar. Photo by Roger Stoutenburgh/ BNL

They chose the Schrodinger Basin, which is about 250 miles south of the lunar equator at a point “almost exactly opposite the Earth-facing direction,” O’Connor explained. This will keep the telescope as “free as possible from electromagnetic interference from Earth,” he added.

Sending the telescope to the far side of the moon created particular challenges. For starters, the telescope had to endure the forces experienced during launch and landing. Once it was on the moon, it had to tolerate the harsh temperature that could drop as low as minus 280 degrees Fahrenheit, and radiation environment, while staying within the mass and power budgets. The instrument mass is less than 282 pounds.

While the landing site is ideal for minimizing electromagnetic noise, it’s difficult to send the information back to Earth with the moon blocking the communication.

Indeed, the ill-fated Apollo 13 mission, which was led by Commander James Lovell and that orbited the moon without landing, was out of communication for about 25 minutes while it was on the far side of the moon.

To gather data from the telescope, the group is sending a satellite that will orbit the moon, enabling communication that has a 1.3 second time delay in each direction as the signal travels to the moon.

The signal processing chain required a state-of-the-art digital chip that could crunch the data as it comes through small antennas and produces a reduced data set small enough to send back to Earth, explained O’Connor, who worked with a core BNL team of six senior scientists and engineers and about a dozen other engineers, technicians and project staff on a final design that took about 16 months to complete

Additionally, the telescope will only generate solar energy during 14 Earth days a month. During another 14 days, the instrument needs to run without recharging its battery.

To protect the telescope against the harsh, cold environment of the moon, the scientists are wrapping the instrument in many layers of an insulating blanket. The heat from its operation should provide enough energy to prevent damage from the cold.

When the radio telescope launches, the four antennas are coiled into a compact spool the size of a soda can. After landing, the latch is released, allowing the antenna to deploy into self-supporting booms three meters long using their own spring force. At this point, several research and development missions are underway to learn more about the moon in preparation for the Artemis 3 manned mission currently planned for the middle of 2027.

LSST/ Rubin Observatory

O’Connor has also been involved for over two decades with the development of a project called the Large Synoptic Survey Telescope that is now called the Vera C. Rubin Observatory in Cerro Pachón, Chile.

Rubin was an astronomer who provided the first evidence of the existence of dark matter.

The much anticipated activation of this observatory, which will allow researchers to look into billions of galaxies, asteroids and even dark matter, will start producing data in July.

O’Connor, who helped with the film part of the observatory’s camera, suggested that the BNL science team is “most interested in what LSST/ Rubin will tell us about the nature of dark energy and dark matter. This will come from analyzing the camera’s images which, paradoxically, reveal the location of dark matter as it ‘bends’ the light traveling towards us from distant regions in the universe.”

More information about the event on May 7 can be found here.

Anže Slosar. Photo from BNL

By Daniel Dunaief

Ever since Ancient Romans and Greeks looked to the stars at night, humans have turned those pinpricks of light that interrupt the darkness into mythological stories.

Two years from now, using a state-of-the-art telescope located in Cerro Pachón ridge in Northern Chile, scientists may take light from 12 billion light years away and turn it into a factual understanding of the forces operating on distant galaxies, causing the universe to expand and the patterns of movement for those pinpricks of light.

While they are awaiting the commissioning of the Vera C. Rubin Observatory, researchers including Brookhaven National Laboratory Physicist Anže Slosar are preparing for a deluge of daily data — enough to fill 15 laptops each night.

An analysis coordinator of the Large Synoptic Survey Telescope’s dark energy science collaboration, Slosar and other researchers from around the world will have a unique map with catalogs spanning billions of galaxies.

Anže Slosar

“For the past five years, we have been getting ready for the data without having any data,” said Slosar. Once the telescope starts producing information, the information will come out at a tremendous rate.

“Analyzing it will be a major undertaking,” Slosar explained in an email. “We are getting ready and hope that we’ll be ready in time, but the proof is in the pudding.”

The Vera C. Rubin Observatory is named for the late astronomer who blazed a trail for women in the field from the time she earned her Bachelor’s Degree from Vassar until she made an indelible mark studying the rotation of stars.

Slosar called Rubin a “true giant of astronomy” whose work was “instrumental in the discovery of dark matter.”

Originally called the Large Synoptic Survey Telescope (LSST), the Rubin Observatory has several missions, including understanding dark matter and dark energy, monitoring hazardous asteroids and the remote solar system, observing the transient optical sky and understanding the formation and structure of the Milky Way.

The study of the movement of distant galaxies, as well as the way objects interfere with the light they send into space, helps cosmologists such as Slosar understand the forces that affect the universe as well as current and ancient history since the Big Bang.

According to Slosar, the observatory will address some of its goals by collecting data in five realms including examining large structures, which are clustered in the sky. By studying the statistical properties of the galaxies as a function of their distance, scientists can learn about the forces operating on them.

Another area of study involves weak lensing. A largely statistical measure, weak lensing allows researchers to explore how images become distorted when their light source passes near a gravitational force. The lensing causes the image to appear as if it were printed on a cloth and stretched out so that it becomes visually distorted.

In strong lensing, a single image can appear as two sources of light when it passes through a dense object. Albert Einstein worked out the mathematical framework that allows researchers to make these predictions. The first of thousands of strong lensing effects was discovered in 1979. Slosar likens this process to the way light behind a wine glass bends and appears to be coming from two directions as it passes around and through the glass.

The fourth effect, called a supernova, occurs when an exploding star reaches critical mass and collapses under its own weight, releasing enough light to make a distant star brighter than an entire galaxy. A supernova in the immediate vicinity of Earth would be so bright, “it would obliterate all life on Earth.”

With the observatory scanning the entire sky, scientists might see these supernova every day. Using the brightness of the supernova, scientists can determine the distance to the object.

Scientists hope they will be lucky enough to see a supernova in a strongly lensed galaxy. Strong lensing amplifies the light and would allow scientists to see the supernova that are otherwise too distant for the telescope to observe.

Finally, the observatory can explore galaxy clusters, which are a rare collection of galaxies. The distribution of these galaxies in these clusters and how they are distributed relative to each other can indicate the forces operating within and between them.

The BNL scientist, who is originally from Slovenia, is a group leader for the BNL team, which has seven researchers, including post docs. As the analysis coordinator of the dark energy science collaboration, he also coordinates 300 people. Their efforts, he said, involve a blend of independent work following their particular interests and a collective effort to prepare for the influx of data.

Slosar said his responsibility is to have a big-picture overview of all the pieces the project needs. He is thrilled that this project, which was so long in the planning and development stage, is now moving closer to becoming a reality. He said he has spent five years on the project, while some people at BNL have spent closer to 20 years, as LSST was conceived as a dark matter telescope in 1996.

Scientists hope the observatory will produce new information that informs current understanding and forms the basis of future theories.

As a national laboratory, BNL was involved in numerous phases of development for the observatory, which had several different leaders. The SLAC National Accelerator in Stanford led the development of the camera that will be integrated into the telescope. BNL will also continue to play a role in the data analysis and interpretation.

“Fundamentally, I just want to understand how the universe operates and why it is like this and not different,” said Slosar.