News Archives

Astronomers Discover Planets in NASA Kepler’s Final Days of Observations

This story was originally published by NASA

 

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Elyse Incha

A team of astrophysicists — including a UW–Madison physics major — and citizen scientists have identified what may be some of the last planets NASA’s retired Kepler space telescope observed during its nearly decade-long mission.

The trio of exoplanets – worlds beyond our solar system – are all between the size of Earth and Neptune and closely orbit their stars.

”These are fairly average planets in the grand scheme of Kepler observations,” said Elyse Incha ’23. “But they’re exciting because Kepler observed them during its last few days of operations. It showcases just how good Kepler was at planet hunting, even at the end of its life.”

A paper about the planetary trio led by Incha was published in the May 30, 2023 issue of the journal Monthly Notices of the Royal Astronomical Society.

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Victor Brar, Wisconsin Center for Semiconductor Thermal Photonics earn UW Research Forward funding

Sixteen projects were chosen in the third round of UW–Madison’s Research Forward competition, including one from Physics.

The Wisconsin Center for Semiconductor Thermal Photonics will explore fundamental science at the intersection of semiconductor technology and radiative heat transfer. This cross-disciplinary center will explore thermal radiation in unconventional semiconductor materials, in nanostructures, and in extreme conditions, and achieve control of the directionality and timing of radiative heat transfer at unprecedented scales. New technologies will emerge from these fundamental studies, including low-cost spectrometers, imaging and ranging, and energy harvesting and active cooling.

The project is led by ECE associate professor and physics affiliate professor Mikhail Kats as Principal Investigator, with Physics associate professor Victor Brar as one of the co-PIs.

Research Forward, a competition sponsored by the Office of the Vice Chancellor for Research and Graduate Education (OVCRGE), is intended to stimulate and support highly innovative and groundbreaking research at UW–Madison.

The initiative is supported by the Wisconsin Alumni Research Foundation (WARF) and will provide funding for 1–2 years, depending on the needs and scope of the project.

 

Three students receive Sophomore Research Fellowships

Three students — two physics majors, one astronomy-physics — have received a UW–Madison Sophomore Research Fellowship as a fellow or honorable mention. The students are:

  • Ella ChevalierAstronomy-Physics; working with Ke Zhang (Astronomy)
  • Erica MageeMathematics, Physics; working with Martin Zanni (Chemistry)
  • Elias MettnerPhysics; working with Abdollah Mohammadi (Physics)

The fellowships include a stipend to each student and to their faculty advisers. Fellowships are funded by grants from the Brittingham Wisconsin Trust and the Kemper K. Knapp Bequest, with additional support from UW-System, the Chancellor’s Office and the Provost’s Office.

Wasikul Islam honored with UW Postdoc Association Excellence in Service Award

Wasikul Islam, a postdoc in Sau Lan Wu’s group, was recognized by the UW–Madison Postdoc Association with an Excellence in Service Award. He was nominated for his science outreach activities, promotion of basic sciences, volunteering and mentorship to undergrad Physics students through various non-profit organizations including the American Physical Society. 

The Postdoc Excellence Awards recognize current postdocs on the UW-Madison campus that contribute their time, knowledge, energy, and enthusiasm to mentoring, teaching, and service. They were established to encourage and reward excellence, innovation, and effectiveness in the mentoring, teaching, and service of UW-Madison postdocs. The 2023 winners were honored at the Celebration of Postdoc Excellence on May 19.

a zoomed out photo shows a man receiving an award from a woman on an elevate stage, with a screen behind them showing his photo, name, and award won
Wasikul Islam receives his award at the 2023 Celebration of Postdoc Excellence, held May 19.

Ke Fang earns NSF CAREER award

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Ke Fang

Congrats to Ke Fang, assistant professor of physics, WIPAC faculty member, and HAWC spokesperson, on earning an NSF CAREER award! CAREER awards are NSF’s most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.

Fang’s award is sponsored by the NSF Windows on the Universe: Multimessenger Astrophysics program. In multimessenger astrophysics, scientists search for multiple high energy signals to identify their sources and learn more about the makeup of our universe. WIPAC hosts both the IceCube neutrino telescope and the HAWC gamma ray telescope, and Fang says she is excited to have access to high-quality data from both. In her NSF proposal, she plans to use that data in two ways.

“One is evolving novel data analysis techniques to study the problems that remain outstanding, such as the source of high-energy neutrinos,” Fang says. “The second part is once we have these data analysis results, then we’ll use numerical simulations to understand our observations.”

In addition to an innovative research component, NSF proposals require that the research has broader societal impacts, such as working toward greater inclusion in STEM or increasing public understanding of science. Once again, Fang finds herself well-positioned at WIPAC, where the outreach team has developed Master Classes, a one-day event where high school students come to WIPAC, spend time with scientists, and learn about topics not typically covered in high school physics class. Currently, the students learn about IceCube’s instrumentation and how to analyze the complex detector data.

“The course is already well designed, but from my perspective, I use a lot of numerical simulation in my research, so one thing I proposed to do is that I would design a module that would incorporate some of these modern numerical study techniques into the master class,” Fang says. “The students will now learn how to study physics using supercomputers, using numerical simulations.”

Researchers capture elusive missing step in the final act of photosynthesis

an abstract background with a 35mm film with several panels showing the molecular process described in the study

This story was modified from one originally published by SLAC

Photosynthesis plays a crucial role in shaping and sustaining life on Earth, yet many aspects of the process remain a mystery. One such mystery is how Photosystem II, a protein complex in plants, algae and cyanobacteria, harvests energy from sunlight and uses it to split water, producing the oxygen we breathe. Now researchers from the Department of Energy’s Lawrence Berkeley National Laboratory and SLAC National Accelerator Laboratory, together with collaborators from the University of Wisconsin–Madison and other institutions have succeeded in cracking a key secret of Photosystem II.

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Uwe Bergmann

Using SLAC’s Linac Coherent Light Source (LCLS) and the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, they captured for the first time in atomic detail what happens in the final moments leading up to the release of breathable oxygen. The data reveal an intermediate reaction step that had not been observed before.

The results, published today in Nature, shed light on how nature has optimized photosynthesis and are helping scientists develop artificial photosynthetic systems that mimic photosynthesis to harvest natural sunlight to convert carbon dioxide into hydrogen and carbon-based fuels.

“The splitting of water to molecular oxygen by photosynthesis has dramatically reshaped our early planet, eventually leading to complex life forms that rely on oxygen for respiration, including ourselves,” says Uwe Bergmann, a physics professor at UW–Madison. “Capturing the final steps of this process in real time with x-ray laser pulses, and bringing to light the individual atoms involved, is thrilling and adds an important piece to solving this over 3-billion-year-old puzzle.”

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Big discoveries, lofty goals highlight astronomy Investiture panel

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This story was originally published by University Communications as part of their coverage of Chancellor Mnookin’s Investiture

A group of astronomers and physicists, including Physics professor Francis Halzen, shared the stories behind their groundbreaking discoveries and lofty goals before a packed house gathered at University of Wisconsin–Madison’s Marquee Theater on Thursday to celebrate the Investiture of Chancellor Jennifer Mnookin.

The scientists included UW–Madison professors Francis Halzen and Susanna Widicus Weaver, as well as Andrea Ghez, a professor at the University of California, Los Angeles and good friend of Chancellor Mnookin. The symposium was titled “Discovery Past, Present, and Future: Black Holes, Neutrinos, and Life in our Galaxy.”

The friendship between Mnookin and Ghez goes back more than 15 years and is filled with fond memories, among them a champagne toast they shared in Ghez’s backyard to mark her winning the 2020 Nobel Prize in Physics. An attorney with a skill for interpreting legalese, Mnookin ensured the celebratory moment would conform with California’s emergency public health rules during the first winter of the COVID-19 pandemic.

“One of the things I love about Chancellor Mnookin is she is a problem solver,” said Ghez, who shared the 2020 prize for the discovery of a supermassive black hole at the center of the Milky Way galaxy.

Ghez recounted the scientific principles, theories and observations that led to the discovery in a talk that reveled in the surprise of the scientific process — a process that is increasingly enabled by new technologies.

“What’s so fun about what I call ‘technology-enabled discovery’ is that almost everything we’ve been able to look at in the center of the galaxy and its environment is inconsistent with the predictions,” Ghez said. “I like to call that either job security or being a kid in a candy shop.”

The rise of new technologies to help answer fundamental questions about the universe was a common theme among the three panelists, who were introduced by Dean Eric Wilcots of the College of Letters & Science and an astronomer himself.

Halzen described the massive telescope built deep within the ice at UW’s IceCube Neutrino Observatory at the South Pole that has enabled the detection of neutrinos, along with plans for an ice-encased observatory 10 times its size. The ghostly particles zip across the universe unimpeded from high-energy sources like the supermassive black holes now believed to be at the center of virtually all large galaxies.

And Widicus Weaver recounted her work hunting for the chemical signatures that might help identify habitable exoplanets — research that has received a massive boost from the James Webb Space Telescope, which began its science mission less than a year ago.

The discussion began with a history lesson provided by Wilcots, who shared the story of Karl Jansky.

A 1927 graduate of UW–Madison who was known at the time as “the fastest skater on the Wisconsin hockey team,” Jansky went on to work for Bell Laboratories. There he sought to understand the sources of static and radio interference — work that eventually led Jansky to observe a major source of radio interference emanating from the constellation of Sagittarius. Decades later, Ghez discovered the likely source — the supermassive black hole at the center of the galaxy.

Jansky’s observations “effectively started the field of radio astronomy,” Wilcots said, noting UW–Madison’s prominent and ongoing contributions to the field via scientists like Halzen, Widicus Weaver and their many colleagues.

The contributions are in their own ways manifestations of the Wisconsin Idea, Mnookin said in her opening remarks.

“When we talk about the Wisconsin Idea and our impact beyond the borders of our campus, it is awesome to think that there are people in our midst pushing that line beyond our planet, our solar system and even our galaxy,” she said.

IceCube search for sub-TeV neutrino emission associated with LIGO/Virgo gravitational waves

Gravitational waves (GWs) are produced by some of the most extreme astrophysical phenomena, such as black hole and neutron star mergers. They have long been suspected as astrophysical sources of neutrinos, ghostlike cosmic messengers hurtling through space unimpeded. Thus far, common astrophysical sources of neutrinos and photons, as well as common sources of gravitational waves and light, have been identified. However, no one has yet detected sources that emit both gravitational waves and neutrinos.

In a study recently submitted to The Astrophysical Journal, the IceCube Collaboration performed a new search for neutrinos from GWs at the GeV-TeV scale. Although no evidence of neutrino emission was found, new upper limits on the number of neutrinos associated with each gravitational wave source and on the total energy emitted by neutrinos for each source were set.

Previously, IceCube searched for neutrinos from GW sources using the TeV-PeV neutrinos detected by the main IceCube Neutrino Observatory, a cubic-kilometer detector enveloped in Antarctic ice at the South Pole. This time, collaborators used data taken with the DeepCore array, the innermost component of IceCube consisting of sensors more densely spaced than in the main array. DeepCore can detect lower energy (GeV and upward) neutrinos than is possible with the larger main array.

a pale yellow oval skymap with a location probability heatmap superimposed
Example map of the sky in neutrinos, overlaid on the localization of gravitational wave event GW 151226. The source of the gravitational wave signal is indicated by the color scale, with darker colors indicating more probable location of the source. The eight neutrinos detected by IceCube DeepCore within ±500 seconds of the gravitational wave are indicated with crosses (best fit) and curves (90% containment). Several neutrinos are spatially compatible with the direction of GW151226, but the association is not statistically significant. The IceCube Upgrade will enable improved localization of such GeV-TeV neutrinos, possibly leading to detection of a common source of gravitational waves and neutrinos. Credit: IceCube Collaboration

The analysis looked for temporal and spatial correlations between 90 GW events detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo gravitational wave detectors and neutrinos detected by DeepCore. The researchers found no significant excess of neutrinos from the direction of the GW events but set stringent upper limits on the neutrino flux and limits on the energies associated with neutrinos from each GW source.

“These results do not mean that all hope is lost for detecting such joint emissions,” says Aswathi Balagopal V., a postdoctoral associate at UW–Madison and co-lead of the analysis. “With improvements in directional reconstructions for low-energy neutrinos, which is expected with better methods and with the inclusion of the IceCube Upgrade, we will be able to achieve better sensitivities for such joint searches, potentially leading to a positive discovery.”

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Dan McCammon earns L&S Distinguished Academic Advising Achievement Award

The College of Letters & Science announced this week that Prof. Dan McCammon has been awarded a 2022-23 Distinguished Academic Advising Achievement Award, the highest advising honor the College bestows.

Persons honored with an L&S Academic Advising award are exceptional advisors. Recipients have demonstrated exemplary performance both in terms of their positive impact on students and through distinctive contributions to their department, unit, and/or the College of Letters & Science.

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Dan McCammon

“Dan is widely known in the physics department for the care and concern he shows to all our students,” says Prof. Thad Walker, chair of the department’s Faculty Recognition committee. “Literally thousands of students have benefitted from his thoughtful, knowledgeable, and non-judgmental advice.”

McCammon joined the Physics faculty in 1980 and has served in a formal or informal advising role ever since. He works tirelessly on behalf of all students in a role which most of them are likely unaware of — as their representative and defender within the physics department.

Katiya Fosdick was one of those students. She was an astronomy-physics major who had been assigned an academic advisor in the astronomy department, but frequently turned to McCammon for discussions about the major, course selection, and issues with workload in courses.

“Dan fights and advocates to do right by his undergraduate constituents,” Fosdick says. “He is motivated by a sense of responsibility and service to students and acts on it.”

McCammon has served as a research advisor for over 220 undergraduate students, both physics and non-physics majors, in addition to his academic advising role. He has served as the faculty mentor to the Undergraduate Physics Club for three decades, worked with the L&S Honors program to increase the honors section offerings in physics courses, and worked closely with the undergraduate course committees to ensure that physics course requirements are appropriate for all students regardless of their graduate school plans.

“Dan has served as an exceptional advisor to thousands of students over decades of service, and his unique understanding and compassionate mentoring has positively impacted students’ lives in myriad ways,” Walker says. “It is a pleasure that the College is acknowledging his outstanding work over so many years with this Distinguished Achievement Advising Award.”

Justin Vandenbroucke receives Vilas Associates award

This story was originally published by WIPAC

UW–Madison physics professor Justin Vandenbroucke was selected as one of 23 awardees of the Vilas Associates Competition. The announcement was made recently by the Office of the Vice Chancellor for Research and Graduate Education.

The competition recognizes “new and ongoing research of the highest quality and significance,” and is open to tenure-track assistant professors and tenured faculty within 20 years of their tenure date. Recipients are chosen based on their research proposals, with winners receiving up to two-ninths of research salary support for the summers of 2023 and 2024, in addition to a $12,500 flexible research fund each of the fiscal years.

“This award will enable my group and me to build on our recent work by branching out in new directions,” says Vandenbroucke. “I’m grateful for the support we receive from the university, the physics department, and WIPAC.”

Vandenbroucke’s work at WIPAC includes research in neutrino astronomy, gamma-ray astronomy, and cosmic rays. Vandenbroucke leads the Distributed Electronic Cosmic-Ray Observatory (DECO), a citizen science project that allows users around the world to detect cosmic rays and other energetic particles with their cell phones and tablets. Vandenbroucke is a member of the IceCube Collaboration and the Cherenkov Telescope Array consortium and an affiliate member of the Fermi LAT collaboration.

The award will be used to support research in multimessenger astrophysics using IceCube and the IceCube Upgrade, now underway, in combination with gravitational wave and gamma-ray observations to discover and study cosmic particle accelerators.

The award is funded by the William F. Vilas Trust Estate.