The Graduate Research Fellowship Program (GRFP) supports high-potential scientists and engineers in the early stages of their careers. Each year, more than 12,000 applicants compete for ~2,000 fellowship awards. NSF GRFP awards are highly sought and competitive. The fellowship is awarded to individuals in the early stages of their graduate study, who intend to pursue research-based graduate studies in science, technology, engineering, and mathematics (STEM).
The program provides awardees with three years of financial support consisting of a $37,000 annual stipend and a $12,000 education allowance. UW–Madison contributes toward fringe benefits.
UW–Madison researchers key in search for neutrino emission from the brightest gamma-ray burst ever detected
On October 9th, 2022, an unusually bright pulse of high-energy radiation whizzed past Earth, captivating astronomers around the world. The luminous emission came from a gamma-ray burst (GRB), one of the most powerful classes of explosions in the universe. Named GRB 221009A, it triggered detectors at NASA’s Gamma-ray Burst Monitor and Large Area Telescope (both on board the Fermi Gamma-ray Space Telescope), the Neil Gehrels Swift Observatory, and the Wind spacecraft as well as other telescopes that quickly turned to the GRB site to study its aftermath.
Jessie Thwaites
This record-shattering GRB is one of the closest and the brightest GRB ever spotted, earning it the nickname BOAT (“brightest of all time”). This GRB is believed to come from an exploding star and likely signals the birth of a black hole.
In a new study by the IceCube Collaboration, published today in The Astrophysical Journal Letters, UW–Madison researchers presented results of one of five searches for neutrino emission from GRB 221009A that leveraged the full detector range, covering nine orders of magnitude in energy. Because no significant emission was found across samples spanning 10 MeV to 10 PeV, the results are the most stringent constraints on neutrino emission from GRBs.
As some of the most energetic sources in the universe, GRBs have long been considered a possible astrophysical source of neutrinos—tiny “ghostlike” particles that travel through space and large amounts of matter unhindered. These high-energy neutrinos are of particular interest to the National Science Foundation-supported IceCube Neutrino Observatory, a gigaton-scale neutrino detector at the South Pole.
IceCube is run by the international IceCube Collaboration, which comprises over 350 scientists from 58 institutions around the world. The Wisconsin IceCube Particle Astrophysics Center (WIPAC), a research center at UW–Madison, is the lead institution for the IceCube project.
Previously, IceCube has performed searches for neutrino emission from GRBs, but thus far, a correlation has not been found between high-energy neutrinos and GRBs. The recent observation of GRB 221009A presented IceCube with the best opportunity yet to search for neutrino emission by GRBs.
Justin Vandenbroucke
“Not only was this GRB the brightest ever detected in gamma rays, it also occurred in a region of the sky where IceCube is very sensitive,” says UW–Madison physics professor Justin Vandenbroucke, who helped lead the analysis.
For the study, collaborators carried out five complementary IceCube analyses that encompassed the full energy range of the detector. Each analysis targeted a specific energy range, with the idea of covering as wide an energy range as possible. UW–Madison physics PhD student Jessie Thwaites was one of the main analyzers.
Thwaites performed a “fast response” analysis based on real-time data from the South Pole to search for high-energy (0.10 teraelectronvolts to 10 petaelectronvolts) neutrinos from the direction of the GRB. They chose two time windows: one three-hour window covering all of the triggers reported in real time, and one covering two days. Their analysis, which set strong constraints on neutrino emission from GRBs, was quickly reported to the community, within hours of the GRB being detected by the gamma-ray satellites.
“In the high energies, our upper limits are very constraining—they are below the observations from gamma-ray telescopes,” says Thwaites. “These upper limits, combined with the observations from many electromagnetic telescopes, give us more information about GRBs as potential particle accelerators.”
Because this GRB is so bright, and because it has been so well studied, IceCube is able to place constraining upper limits on neutrino emission models proposed for this specific GRB. These constraints will enable better understanding of how GRBs work.
The collaborators are already developing new methods to improve searches for neutrinos from GRBs and other transient astrophysical sources. In addition, future upgrades and proposed extensions of IceCube, including the IceCube Upgrade project and IceCube-Gen2, could be the key to finding high-energy neutrino emission from GRBs or other transients.
According to Vandenbroucke, “This GRB illustrates the capabilities of IceCube for real-time follow-up of astrophysical transients. IceCube views the entire sky, all the time, over a factor of a billion in energy range. There is likely a burst of neutrinos already flying towards us from some other cosmic source, and we are ready for it.”
+ info “Limits on Neutrino Emission from GRB 221009A from MeV to PeV using the IceCube Neutrino Observatory,” The IceCube Collaboration: R. Abbasi et al. Published in The Astrophysical Journal Letters. arxiv.org/abs/2302.05459
IceCube performs the first search for neutrinos from novae
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White dwarfs are very dense, compact objects that are one of the possibilities for the final evolutionary state of stars. If they happen to be in a binary system with another companion star, the white dwarf may pull material from the companion star onto its surface. In this case, if enough material is accumulated, a nuclear reaction may occur on the surface of the white dwarf, causing a luminous burst of photons called a nova. Historically, astronomers believed they were seeing stars being born, hence the name, although we now know that is not the case. In the past decade, GeV and even TeV gamma rays were discovered from novae, suggesting that neutrinos—neutral, nearly massless cosmic messengers—could originate from novae as well.
In a paper recently submitted to The Astrophysical Journal, the IceCube Collaboration presents its first search for neutrinos from novae using a subarray of the IceCube Neutrino Observatory, a gigaton-scale detector operating at the South Pole. Although significant emission from novae was not found, IceCube set the first observational upper limits on neutrino emission from novae.
According to Justin Vandenbroucke, professor of physics at the University of Wisconsin–Madison and one of the study leads, “Novae, the little cousins of supernovae, are one of the longest known types of astrophysical transient. The discovery that they produce gamma rays was a huge surprise. Our neutrino analyses are starting to add to the modern understanding of these historical phenomena.”
NASA’s Fundamental Physics Program has selected seven proposals, including one from UW–Madison physics professor Shimon Kolkowitz, submitted in response to the Research Opportunities in Space and Earth Sciences – 2022 Fundamental Physics call for proposal.
The selected proposals are from seven institutions in seven states, with the total combined award amount of approximately $9.6 million over a five-year period. Kolkowitz’s proposal is ““Developing new techniques for ultra-high-precision space-based optical lattice clock comparisons.”
Three of the selected projects will involve performing experiments using the Cold Atom Laboratory (CAL) aboard the International Space Station (ISS). Four of the selected proposals call for ground-based research to help NASA identify and develop the foundation for future space-based experiments.
The Fundamental Physics Program is managed by the Biological and Physical Sciences Division in NASA’s Science Mission Directorate. This program performs carefully designed research in space that advances our understanding of physical laws, nature’s organizing principles, and how these laws and principles can be manipulated by scientists and technologies to benefit humanity on Earth and in space.
Justin Marquez and Sam Kramer named L&S Teaching Mentors
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Justin MarquezSam Kramer
Congrats to physics PhD students Justin Marquez and Sam Kramer on being named 2023-24 L&S Teaching Mentors!
The L&S TA Training & Support Team is responsible for welcoming and training hundreds of new TAs each year. Teaching Mentors are the heart of this crucial undertaking: they serve as facilitators at the annual L&S Fall TA Training event and provide mentorship throughout the semester. Those selected to be Teaching Mentors have not only a proven track record of excellence as educators, but also a strong desire to share their experience and mentor new TAs navigating their first year.
Twenty-one outstanding graduate students — including physics PhD student Soren Ormseth — have been selected as recipients of the 2022-23 UW–Madison Campus-Wide Teaching Assistant Awards, recognizing their excellence in teaching. Ormseth earned a Dorothy Powelson Teaching Assistant Award.
UW–Madison employs over 2,300 teaching assistants (TAs) across a wide range of disciplines. Their contributions to the classroom, lab, and field are essential to the university’s educational mission. To recognize the excellence of TAs across campus, the Graduate School, the College of Letters & Science (L&S), and the Morgridge Center sponsor these annual awards.
Ormseth is a graduate student in the Department of Physics specializing in detector physics. He has taught intermediate physics lab and intermediate electronics lab.
“The best teachers hone their communication skills to make subject material and lessons interesting, relevant, well organized, and right at that difficulty-sweet-spot. At the end of the day though, every student has their own unique way of looking at the world and engaging with a particular topic,” Ormseth said. “When it comes time to deliver a lecture, write a textbook, or create a presentation, a teacher needs to work on those communication skills. But when it comes time to engage with an individual student, the best thing that a teacher can do is be approachable, flexible, and willing to listen with the intent to understand the student’s perspective. Mastering these two teaching modes is a lifelong journey which never stops!”
Help IceCube decode signals from outer space in new Citizen Science project
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Every second, about 100 trillion neutrinos pass through your body unnoticed. At the South Pole, the IceCube Neutrino Observatory detects these elusive particles and works to identify their astronomical origins to help unlock mysteries of the universe. Such an undertaking requires a massive amount of data, with one terabyte of data recorded daily by IceCube. But organizing the data can be labor intensive. This is where the public can help.
Starting today, volunteers from anywhere can participate in the Name that Neutrino project led by IceCube researchers at Drexel University, which asks users to categorize IceCube data. Through the Zooniverse platform, volunteers can join in from the convenience of their own computer or phone. Name that Neutrino is open to everyone and will run for about 10 weeks.
Click “Tutorial” to learn about how to classify signals.
Watch the brief video and pick one of the five categories for signals.
Check out the “Field Guide” for more examples and information.
Royal visit strengthens WIPAC and IceCube’s partnership with Thailand
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A budding collaboration between the Wisconsin IceCube Particle Astrophysics Center and Chiang Mai University in Thailand took a grand turn with a visit to the Royal Palace in Bangkok. There, discussions between scientists from WIPAC, a University of Wisconsin–Madison research center, and Her Royal Highness Princess Maha Chakri Sirindhorn explored how to increase research opportunities for Thai researchers and technical staff at the IceCube Neutrino Observatory.
IceCube, a unique telescope that has instrumented a billion tons of South Pole ice, searches for tiny, ghostlike particles called neutrinos to study the most powerful cosmic engines in the universe. HRH Sirindhorn’s fascination with physics, astronomy and Antarctic research has become evident in her strong advocacy for this work in general and IceCube science in particular.
The Wonders of Physics shows in Chamberlin Hall, Feb 11-12 and Feb 18-19, kept the audience riveted with scientific experiments that demonstrated physics principles with panache. It also was a landmark show of sorts, as Professor Clint Sprott handed over control to Haddie McLean in the show’s 40th year. The show aims to to generate interest in physics among people of all ages and backgrounds.
New quantum sensing technique reveals magnetic connections
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By Leah Hesla, Q-NEXT
A research team supported by the Q-NEXT quantum research center demonstrates a new way to use quantum sensors to tease out relationships between microscopic magnetic fields.
Say you notice a sudden drop in temperature on both your patio and kitchen thermometers. At first, you think it’s because of a cold snap, so you crank up the heat in your home. Then you realize that while the outside has indeed become colder, inside, someone left the refrigerator door open.
Initially, you thought the temperature drops were correlated. Later, you saw that they weren’t.
Recognizing when readings are correlated is important not only for your home heating bill but for all of science. It’s especially challenging when measuring properties of atoms.
Now scientists — including those from UW–Madison physics professor Shimon Kolkowitz‘s group — have developed a method, reported in Science, that enables them to see whether magnetic fields detected by a pair of atom-scale quantum sensors are correlated or not.
