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Mysteries of the Universe

June 4, 2021

Mysteries of the universe

Utah researchers join project to unlock enigma of 'dark energy'

Researchers from the University of Utah are joining forces with others for a universal five-year project that seeks to map the universe and gain insights into the mysteries of dark energy.

In a culture where science fiction reigns as one of the most popular genres for movies and television, the terms "dark matter" and "dark energy" likely convey a sense of foreboding to many.

But they got their label simply because scientists know so little about them, said Angela Berti, a U. postdoctoral researcher working on the project.

"You hear 'dark matter, dark energy' kind of thrown out there, and to the extent that you've kind of read popular science news, you might be aware that the astronomy community and the physics community knows that there's some additional mass out there in the universe," she said.

In the last 20 years, researchers discovered that the universe continues expanding at an increasingly rapid rate, which is considered "strange and unusual," according to Berti.

"We don't really have a great explanation for it. So the placeholder, we call it dark energy, something that's causing the universe to expand faster and faster," she said.

The Dark Energy Spectroscopic Instrument, also known as DESI, in Tucson, Arizona, will collect data on the light from more than 30 million galaxies and other distant objects, which researchers will use to make a 3D map of the universe. DESI captures spectra, which are elements of light that correspond to the colors of the rainbow. Spectras split light into wavelengths, or redshifts, which researchers measure to find the distance to a galaxy or far-off object in space.

The project launched officially in mid-May after years of preparation. About 50 universities are participating in the U.S. and around the world.

With millions of galaxies to map, the researchers will use an algorithm to find the best estimate for distances between objects. Berti's role includes checking data on sample subsets of individual galaxies and spectra to make sure the algorithm data aligns. She will help find objects for which the algorithm is less effective in estimating distances, so researchers can improve the system.

"It's kind of cool because the reason it's really useful is when you have millions and millions of galaxies, you can't do that process by hand for every single one," Berti said.

She's also testing alternative modeling techniques for measuring redshifts.

DESI is the largest project so far to measure "very precisely the expansion rate of the universe, basically to just measure more precisely the rate at which it's expanding, and the rate at which the expansion might be changing," Berti said.

It will measure galaxies in one-third of the entire sky, she said.

The researchers don't know what they'll discover. But to make progress in understanding why the universe is expanding faster and faster, they need to measure that expansion as precisely as possible.

She said the project seeks to indirectly unravel some of the mysteries surrounding dark energy, which like dark matter, has eluded scientists for many years.

"The frustration and the foreboding comes from the fact that we haven't yet figured out what it is. It doesn't mean that we won't figure it out, and it doesn't mean that our current science is wrong, it just means that our current understanding is incomplete. And that's frustrating. ... They're two big, pressing mysteries that are yet uncracked," Berti said.

The project will "help us understand the properties of this unexplained phenomena better, and the more we understand the details about what's going on, the better chance we have of coming up with a theory that we can test," she said.

 

By Ashley Imlay, first published in KSL.com

Carsten Rott

January 13, 2021

Carsten Rott

Professor Carsten Rott, who will join the Department of Physics & Astronomy in early 2021, has been appointed to the Jack W. Keuffel Memorial Chair, effective January 1, 2021. Rott will hold the chair through December 2025.

“It’s such a great honor to be appointed, and I’m looking forward to my arrival at the U to begin my work,” he said.

The Jack W. Keuffel Memorial Chair in Physics & Astronomy was established to honor and continue the work the late Jack W. Keuffel, a professor and pioneer in cosmic ray research at the U from 1960-1974.

More About Rott
For as long as he can remember, Rott has been fascinated by the night sky, the stars, and the planets. As a child growing up in Germany, he could see the Orion nebula, the Andromeda galaxy, and star clusters. He wondered what these objects were and what else was in the night sky waiting to be discovered.

He combined his love of astronomy with learning computer programing and was fascinated by the ability to write computer programs to model biological systems, fluid dynamics, and astrophysics. By comparing the outcomes of his simulations, he could check to see if his intuition was correct or if he got the physics right, which was invaluable in training his logical thinking skills. “As a high school student, I spent many months trying to understand why my simulations of rotating galaxies would not maintain spiral arm structures or why my models of stars weren’t stable,” he said. Struggling with such questions made him want to understand the underlying phenomena.

Rott studied physics as an undergraduate at the Universität Hannover and went on to receive a Ph.D. from Purdue University in 2004. “Becoming a physicist has at times been a challenge, but it has broadened my horizons so much, and I’m extremely happy I decided to pursue a career in science,” he said.

High-Energy Neutrinos
His research is on understanding the origins of high energy neutrinos, which are tiny, subatomic particles similar to electrons, but with no electrical charge and a very tiny mass. Neutrinos are abundant in the universe but difficult to detect because they rarely interact with matter. These particles originate from distant regions of the universe and can arrive on the Earth more or less unhindered, providing scientists with information about distant galaxies. High-energy neutrinos are associated with extreme cosmic events, such as exploding stars, gamma ray bursts, outflows from supermassive black holes, and neutron stars, and studying them is regarded as a key to identifying and understanding cosmic phenomena.

“One of my main research focuses is to look for signatures of dark matter with high-energy neutrinos. By studying them, we can explore energy scales far beyond the reach of particle accelerators on Earth,” he said.

While most of his work is considered pure research and doesn’t have immediate applications, Rott did figure out a new way to use neutrino oscillations to study the Earth’s interior composition. He spent several months at the Earthquake Research Institute at the University of Tokyo to collaborate with researchers on the topic, and he hopes this new method can help scientists better understand and predict earthquakes.

IceCube Neutrino Telescope
Rott has been a member of the IceCube Neutrino Telescope since the start of the construction of the detector in 2005. IceCube is the world’s largest neutrino detector designed to observe the cosmos from deep within the South Pole ice. The telescope uses an array of more than 5,000 optical sensor modules to detect Cherenkov light, which occurs when neutrinos interact in the ultra-pure Antarctic ice. When a neutrino interaction occurs, a faint light flash is produced, allowing them to be detected.

The IceCube Neutrino Observatory at NSF's Amundsen-Scott South Pole Station Credit: Mike Lucibella, Antarctic Sun

Approximately 300 physicists from 53 institutions in 12 countries are part of the IceCube Collaboration, which tries to solve some of the most fundamental questions of our time, such as the origin of cosmic rays, nature of dark matter, and the properties of neutrinos. The science spectrum covered by the IceCube Neutrino Observatory is very broad, ranging from cosmic ray physics, particle physics, and geophysics to astroparticle physics.

The team of scientists has already achieved some amazing scientific breakthroughs with this telescope. For example, they discovered a diffuse astrophysical neutrino flux in 2014 and recently achieved the first step in identifying the sources of astrophysical neutrinos associated with a highly luminous blazar, which was discovered in 2018. A blazar is an active galaxy that contains a supermassive black hole at its center, with an outflow jet pointed in the direction of the Earth. Over the next years, the team looks forward to making more discoveries by observing the universe in fundamentally new ways.

Life in Korea
Before joining the U, Rott was invited to Korea to begin a tenure-track faculty position at Sungkyunkwan University (SKKU). He took the opportunity to build an astroparticle physics program at one of the major research hubs in Asia. “I was excited to be part of a university that had the vision and determination to become a world-leading university, and I was able to build one of the largest astroparticle physics efforts in Asia, while accomplishing many of my research objectives,” he said.

He enjoys Korean culture and life in Korea, which is very practical and straightforward. “In Korea, people like to get things done fast,” he said. “It’s great to get rapid feedback, for example, on a proposal. You know quickly if your proposal is funded or not.” Being based in Korea has allowed him to collaborate more closely on other projects, including the COSINE-100 dark matter experiment in Korea and the JSNS2 sterile neutrino search and Hyper-Kamiokande neutrino program in Japan. He plans to spearhead initiatives to establish stronger ties between the University of Utah and leading universities in Asia and Korea.

Future Research
Currently, the IceCube team is in the middle of preparing an upgrade to the IceCube Neutrino Telescope. This new telescope will be installed within two years in Antarctica. For the IceCube upgrade, Professor Rott’s team has designed a more accurate camera-based calibration system for the Antarctic ice. Improved calibration will be applied to data collected over the past decade, improving the angular and spatial resolution of detected astrophysical neutrino events.

“The origin of high-energy neutrinos and any new phenomena associated with their production remains one of the biggest challenges of our time,” Rott said. “I’m extremely excited about correlating observations of high-energy neutrinos with other cosmic messengers. To establish any correlation, it’s essential that we can accurately point back to where neutrinos originated on the sky.”

Rott further explains, “We hope that the IceCube upgrade will be just the first step towards a much larger facility for multi-messenger science at the South Pole that combines optical and radio neutrino detection with a cosmic ray air shower array.”

 

by Michele Swaner - Physics & Astronomy News

 

Priyam Patel

January 6, 2021

Priyam Patel

Visualizing the Topology of Surfaces

Imagine a surface that looks like a hollow doughnut. The “skin” of the doughnut has no thickness and is made of stretchy, flexible material. “Some of my favorite mathematical problems deal with objects like this–surfaces and curves or loops on such surfaces,” said Priyam Patel, assistant professor of mathematics, who joined the Math Department in 2019. “I like how artistic and creative my work feels, and it’s also very tangible since I can draw pictures representing different parts of a problem I’m working on.”

Patel works in geometry and topology. The two areas differ in that geometry focuses on rigid objects where there is a notion of distance, while topological objects are much more fluid. Patel likes studying a geometrical or topological object extensively so that she’s able to get to know the space, how it behaves, and what sort of phenomena it exhibits. In her research, Patel’s goals are to study and understand curves on surfaces, symmetries of surfaces, and objects called hyperbolic manifolds and their finite covering spaces. Topology and geometry are used in a variety of fields, including data analysis, neuroscience, and facial recognition technology. Patel’s research doesn’t focus on these applications directly since she works in pure mathematics.

Challenges as a Minority

Patel became fascinated with mathematics in high school while learning to do proofs. She was fortunate to have excellent high school math teachers, who encouraged her to consider majoring in math in college. “When I was an undergraduate at New York University (NYU), I had a female professor for multivariable calculus who spent a lot of time with me in office hours and gave me challenging problems to work on,” said Patel. “She was very encouraging and had a huge impact on me.”

As a woman of color, Patel often felt out of place in many of her classes at NYU. Later, she was one of a handful of women accepted into a Ph.D. program at Rutgers University. Unfortunately, these experiences led to strong feelings of “impostor syndrome” for her as a graduate student. Eventually, she overcame them and learned to celebrate her successes, focusing on the joy that mathematics brings to her life. She has also worked to find a community of mathematicians to help support her through the tough times. “I’ve received a lot of encouragement from friends and mentors both in and outside of my math community,” she said. “I feel especially fortunate to have connected with strong women mentors in recent years.”

Mentors and Outside Interests

Feng Luo, professor of mathematics at Rutgers, was Patel’s Ph.D. advisor, and he played an active role in the early years of her math career. “Talking about math with Dr. Luo is always a positive experience, and his encouragement has been pivotal to my success as a mathematician,” said Patel. Another mentor is Alan Reid, chair and professor of the Department of Mathematics at Rice University. Patel notes that there are many aspects to being a mathematician outside of math itself, and these mentors have helped her navigate her career and offered support, encouragement, and advice.

Patel loves mathematics but makes time for other things in life. She enjoys rock climbing, yoga, dancing, and painting. Music is also a huge part of her life, and she sings and plays the guitar.

Future Research

Patel is currently working on problems concerning groups of symmetries of certain surfaces. Specifically, she has been studying the mapping class groups of infinite-type surfaces, which is a new and quickly growing field of topology. “It’s quite exciting to be at the forefront of it. I would like to tackle some of the biggest open problems in this area in the next few years, such as producing a Nielsen-Thurston type classification for infinite-type surfaces,” she said. She is also interested in the work of Ian Agol, professor of mathematics at Berkeley, who won a Breakthrough Prize in 2012 for solving an open problem in low-dimensional topology. Patel would like to build on Agol’s work in proving a quantitative version of his results. Other areas she’d like to explore are the combinatorics of 3-manifolds and the theory of translation surfaces.

 

by Michele Swaner

 

Next-Gen Astronomy

November 3, 2020

 

Gail Zasowski

Next-gen astronomical survey makes its first observations.

The Sloan Digital Sky Survey’s fifth generation collected its very first observations of the cosmos at 1:47 a.m. on October 24, 2020. As the world’s first all-sky time-domain spectroscopic survey, SDSS-V will provide groundbreaking insight into the formation and evolution of galaxies—like our own Milky Way—and of the supermassive black holes that lurk at their centers.

Funded primarily by member institutions, along with grants from the Alfred P. Sloan Foundation, the U.S. National Science Foundation, and the Heising-Simons Foundation, SDSS-V will focus on three primary areas of investigation, each exploring different aspects of the cosmos using different spectroscopic tools. Together these three project pillars—called “Mappers”—will observe more than six million objects in the sky, and monitor changes in more than a million of those objects over time.

The survey’s Local Volume Mapper will enhance our understanding of galaxy formation and evolution by probing the interactions between the stars that make up galaxies and the interstellar gas and dust that is dispersed between them. The Milky Way Mapper will reveal the physics of stars in our Milky Way, the diverse architectures of its star and planetary systems, and the chemical enrichment of our galaxy since the early universe. The Black Hole Mapper will measure masses and growth over cosmic time of the supermassive black holes that reside in the hearts of galaxies, and of the smaller black holes left behind when stars die.

“We are thrilled to start taking the first data for two of our three Mappers,” added SDSS-V spokesperson Gail Zasowski, an assistant professor in the University of Utah’s Department of Physics & Astronomy. “These early observations are already important for a wide range of science goals. Even these first targets provide data for studies ranging from mapping the inner regions of supermassive black holes and searching for exotic multiple-black hole systems, to studying nearby stars and their dead cores, to tracing the chemistry of potential planet-hosting stars across the Milky Way.”

A sampling of data from the first SDSS-V observations. Center: The telescope’s field-of-view, with the full Moon shown for scale. SDSS-V simultaneously observes 500 targets at a time within a circle of this size. Left: the optical-light spectrum of a quasar, a supermassive black hole at the center of a distant galaxy, which is surrounded by a disk of hot, glowing gas. The purple blob is an SDSS image of the light from this disk, the width of a human hair as seen from about 21 meters (63 feet) away. Right: The image and spectrum of a white dwarf –the left-behind core of a low-mass star (like the Sun) after the end of its life.

The newly-launched SDSS-V will continue the path-breaking tradition set by the survey’s previous generations, with a focus on the ever-changing night sky and the physical processes that drive these changes, from flickers and flares of supermassive black holes to the back-and-forth shifts of stars being orbited by distant worlds. SDSS-V will provide the spectroscopic backbone needed to achieve the full science potential of satellites like NASA’s TESS, ESA’s Gaia, and the latest all-sky X-ray mission, eROSITA.

As an international consortium, SDSS has always relied heavily on phone and digital communication. But adapting to exclusively virtual communication tactics since the beginning of the COVID-19 pandemic was a challenge, along with tracking global supply chains and laboratory availability at various university partners as they shifted in and out of lockdown during the final ramp-up to the survey’s start. Particularly inspiring were the project’s expert observing staff, who worked in even-greater-than-usual isolation to shut down, and then reopen, the survey’s mountain-top observatories.

“In a year when humanity has been challenged across the globe, I am so proud of the worldwide SDSS team for demonstrating—every day—the very best of human creativity, ingenuity, improvisation, and resilience.” said SDSS-V director Juna Kollmeier, of the Carnegie Observatories. “It has been a challenging period for SDSS and the world, but I’m happy to report that the pandemic may have slowed us, but it has not stopped us.”

Anil Seth


The University of Utah will actually operate as the data reduction center for SDSS-V, supported by the U’s Center for High Performance Computing. Joel Brownstein, a research associate professor in the Department of Physics & Astronomy, is the head of data management and archiving for SDSS-V. “As we see the first observations streaming to Utah from the mountain observatories, we are just starting to grasp the amazing potential of this ambitious data set. We are fully and proudly committed to making our results more accessible to the larger community by introducing new tools that enable a dynamic, user-driven experience.”

SDSS-V will operate out of both Apache Point Observatory in New Mexico, home of the survey’s original 2.5-meter telescope, and Carnegie’s Las Campanas Observatory in Chile, where it uses the 2.5-meter du Pont telescope.

SDSS-V’s first observations were taken in New Mexico with existing SDSS instruments, in a necessary change of plans due to the pandemic. As laboratories and workshops around the world navigate safe reopening, SDSS-V’s own suite of new innovative hardware is on the horizon—in particular, systems of automated robots to aim the fiber optic cables used to collect the light from the night sky. These robots will be installed at both observatories over the next year. New spectrographs and telescopes are also being constructed to enable the Local Volume Mapper observations.

Dr. Anil Seth, the University of Utah’s representative on the Advisory Council that oversees SDSS’s operations, highlighted the impact of the project’s open data policies and worldwide collaboration. “SDSS’s 20-year legacy has touched nearly every astronomer in the world by this point. It has become the go-to reference for astronomy textbooks on galaxies, made the most precise measurements of how our Universe is expanding, and showed us how powerful shared data can be. I look forward to see what new results SDSS V will reveal!”

For more information, please see the SDSS-V’s website at www.sdss5.org.

Adapted from a release by the Carnegie Observatories. Also published in @theU

11 Billion Years

August 5, 2020

 

 

Professor Kyle Dawson

11 billion years of history in one map: Astrophysicists reveal largest 3D model of the universe ever created.

(CNN) A global consortium of astrophysicists have created the world's largest three-dimensional map of the universe, a project 20 years in the making that researchers say helps better explain the history of the cosmos.

The Sloan Digital Sky Survey (SDSS), a project involving hundreds of scientists at dozens of institutions worldwide, collected decades of data and mapped the universe with telescopes. With these measurements, spanning more than 2 million galaxies and quasars formed over 11 billion years, scientists can now better understand how the universe developed.

Image courtesy of SDSS

"We know both the ancient history of the Universe and its recent expansion history fairly well, but there's a troublesome gap in the middle 11 billion years," cosmologist Kyle Dawson of the University of Utah, who led the team that announced the SDSS findings on Sunday. "For five years, we have worked to fill in that gap, and we are using that information to provide some of the most substantial advances in cosmology in the last decade," Dawson said in a statement.

Here's how it works: the map revealed the early materials that "define the structure in the Universe, starting from the time when the Universe was only about 300,000 years old." Researchers used the map to measure patterns and signals from different galaxies, and figure out how fast the universe was expanding at different points of history. Looking back in space allows for a look back in time.

"These studies allow us to connect all these measurements into a complete story of the expansion of the Universe," said Will Percival of the University of Waterloo in the statement.

The team also identified "a mysterious invisible component of the Universe called 'dark energy,'" which caused the universe's expansion to start accelerating about six billion years ago. Since then, the universe has only continued to expand "faster and faster," the statement said.

Image courtesy of SDSS

There are still many unanswered questions about dark energy -- it's "extremely difficult to reconcile with our current understanding of particle physics" -- but this puzzle will be left to future projects and researchers, said the statement.

Their findings also "revealed cracks in this picture of the Universe," the statement said. There were discrepancies between researchers' measurements and collected data, and their tools are so precise that it's unlikely to be error or chance. Instead, there might be new and exciting explanations behind the strange numbers, like the possibility that "a previously-unknown form of matter or energy from the early Universe might have left a trace on our history."

The SDSS is "nowhere near done with its mission to map the Universe," it said in the statement. "The SDSS team is busy building the hardware to start this new phase (of mapping stars and black holes) and is looking forward to the new discoveries of the next 20 years."

 

Adapted from a release by Jordan Raddick, SDSS public information officer
Also published in @theU, Spectrum Magazine, CNN, Forbes, and more.

 

New Physics

June 1, 2019

A decision to take a physics class for “fun” During her senior year at New York University changed the Course of Pearl Sandick’s life. At the time, Sandick was majoring In math and had planned to continue her studies in a Ph.D. Program. “The professor noticed that I was enjoying the physics Class and suggested that I think about a physics graduate program Instead of math,” said Sandick, associate professor of physics and Astronomy and associate chair of the U’s Department of Physics & Astronomy. “I was floored—no professor had ever directly Encouraged me like that before—and she had a good point: I did Enjoy physics. After some serious conversations with my mom and My professors, I decided to make the switch. The encouragement of one professor literally made all the difference.”

She earned a Ph.D. From the University of Minnesota in 2008 and Was a postdoctoral fellow in the Theory Group at the University of Texas at Austin before moving to Utah and the U in 2011.

Beyond the Standard Model

As a theoretical particle physicist, Sandick is able to study some of the largest and smallest things in the universe. Dark matter Is the mysterious stuff that gravitationally binds galaxies and Clusters of galaxies together, but despite large-scale evidence for the existence of dark matter, there are compelling arguments that Dark matter might actually be a new type of elementary particle. Some particles are composite, like protons and neutrons. Electrons Are an example of an elementary particle—they are the most Fundamental building blocks of their type and are not composed of other particles. Other examples of elementary particles include Quarks, neutrinos, and photons.

The Standard Model of Particle Physics is the theory that explains how all the elementary particles interact with each other and combine to form composite objects like protons and neutrons. Pearl Sandick 7 The Standard Model can make amazingly accurate predictions, which are tested in collider experiments and with cosmological observations, but the theory has some shortcomings that make particle physicists think there must be something beyond the Standard Model. For example, the Standard Model does not include a satisfactory explanation for the dark matter in the universe. Sandick’s research, currently supported by the National Science Foundation, is in exploring theories of “new physics” that fix theoretical problems with the Standard Model and explain previously unexplained phenomena like dark matter. “For any interesting new theory, my research proposes ways to experimentally support or falsify it, with the hope of eventually identifying the true fundamental theory of nature,” said Sandick.

Challenges for Women in Physics

Women are still widely underrepresented in physics. In college, Sandick got used to being one of the very few women in the room, and in graduate school, she wanted to become a physics professor at a time when only 5% of full professors in physics were women. “Like many women in male-dominated professions, I’ve experienced my share of ‘gender- related weirdness,’” she said. “Every day I’m thankful that the bulk of my negative gender-related experiences are, and continue to be, primarily exhausting and disappointing rather than dangerous or devastating.” Sandick notes that there are still a lot of equity and cultural issues to address in the field. “Science should be for everyone, and there’s a lot of work to be done to address the complex issues that lead to severe underrepresentation of certain groups. If we want to see change, we need to listen, learn, and do the work to make science more inclusive,” she said.

Sandick is committed to organizations that support women in physics. She has served on the American Physical Society’s (APS) Committee on the Status of Women in Physics (CSWP) and was recently the Chair of the National Organizing Committee for the APS Conferences for Undergraduate Women in Physics (CUWiP) The APS CUWiP hosts approximately 2,000 undergraduate physics majors each January at various locations around the country to discuss science, career paths for physicists, and social issues that can affect the experiences of scientists from underrepresented groups. Locally, she is the founder and faculty sponsor of the University of Utah Women in Physics and Astronomy (WomPA).

When she isn’t teaching or doing research, she spends every minute with her family—a three-year-old daughter and a supportive husband.

“This is an incredibly exciting time for dark matter and particle physics,” said Sandick. “We’re still searching for physics beyond the Standard Model, including an explanation for dark matter, so there’s still a lot of work to be done. Right now, one of the most exciting challenges is using experimental data in novel ways in order to get every bit of information out of it that we possibly can. It’s a great time to be creative in terms of how new physics might look from the theoretical point of view and how it might appear in current or upcoming experiments.”