Professor of Physics Nora Berrah has been awarded the International Blaise Pascal Chaire d’Excellence, a prestigious honor whose previous winners include scientists and scholars from a wide range of disciplines, including multiple Nobel laureates. Her award was selected by a committee of scientists and voted on by the Permanent Commission Regional Council of the Région Île-de-France.
Prof. Berrah in her laboratory.
This award is bestowed to scientists of international reputation who are invited to conduct research in the Paris area. The goal is to establish international collaborations and exchange, as well as share science globally. In Berrah’s case, the collaboration is between UConn and the Commissariat à l’énergie atomique et aux énergies alternatives de Saclay (CEA, Paris Saclay). The collaborative work is aimed to push the frontiers of science, as well as enrich and facilitate international research.
The Région Île-de-France selects every year four laureates of high international standing in their field of expertise. All research areas are included, such as the humanities, arts, and sciences, in the selection of the awardees. Six Nobel laureates have been selected for the award since 1996. Prof. Berrah was selected by the Blaise Pascal Chaire Committee for the field of Fundamental Physics.
UConn astrophysicist Chiara Mingarelli is part of a team of researchers who recently published data on a hint of a signal that sent ripples of excitement through the physics community. These monumental findings are the culmination of twelve and a half years of data gathered from NANOGrav — a network of pulsars across the galaxy — all in the hopes of detecting gravitational waves.
Gravitational waves are generated when galaxies merge and supermassive black holes at their centers collide and send low-frequency gravitational waves out into the universe. The team thinks the source of the signal could be gravitational waves, but it will take about 2 more years of data to be sure.
The findings sparked the interest of other physicists with their own speculations about the signal, such as cosmic strings or primordial black holes. Though still a couple of years away, Mingarelli says the final results could also help test General Relativity or even open the door to entirely new physics.
This article first appeared on UConn Today, February 15, 2021
November 2, 2020 – Elaina Hancock – UConn Communications
The Sloan Digital Sky Survey’s fifth generation – a groundbreaking project to bolster our understanding of the formation and evolution of galaxies, including the Milky Way – collected its very first observations on the evening of October 23.
Image: The Sloan Digital Sky Survey’s fifth generation made its first observations earlier this month. This image shows a sampling of data from those first SDSS-V data. The central sky image is a single field of SDSS-V observations. The purple circle indicates the telescope’s field-of-view on the sky, with the full Moon shown as a size comparison. SDSS-V simultaneously observes 500 targets at a time within a circle of this size. The left panel shows 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, which in this dataset spans about 1 arcsecond on the sky, or the width of a human hair as seen from about 21 meters (63 feet) away. The right panel shows 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.Image Credit: Hector Ibarra Medel, Jon Trump, Yue Shen, Gail Zasowski, and the SDSS-V Collaboration. Central background image: unWISE / NASA/JPL-Caltech / D.Lang (Perimeter Institute).
“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. It has been a wild ride, but I’m happy to say that the pandemic may have slowed us, but it has not stopped us,” says Juna Kollmeier, director of the project known as SDSS-V.
The project is funded primarily by an international consortium of member institutions, along with grants from the Alfred P. Sloan Foundation, U.S. National Science Foundation, and the Heising-Simons Foundation.
Jonathan Trump, UConn assistant professor of physics, has a long history with SDSS, and is one of the architects for the fifth installment of the program. He is also serving as the cadence coordinator for the project’s black hole science goals.
“My very first undergrad research project was an SDSS project. I have worked on SDSS as a post-doc, and I am working on it now as faculty,” Trump says. “I’ve been part of it from the first SDSS iteration, and as it has taken off, so has my career.”
Trump and his colleagues will focus on three primary areas of investigation with SDSS-V, 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, as well as the smaller black holes left behind when stars die.
Trump says another novel aspect of SDSS-V is repeat observation, which he will be scheduling over the duration of the project as cadence coordinator, to help gather more data about the evolution of different features of matter near black holes.
“SDSS-V has more repeat observations as part of the plan. I would say that broadly in astronomy there is an emphasis on repeat observations,” he says. “For instance, black holes are fascinating – they are rips in space-time, and they are extremely exotic. Even one snapshot reveals how exotic they are, but they are also dramatically variable, and when we observe them day-to-day, week-to-week, year-to-year, we see dramatic changes in their emission, which we think correspond to dramatic changes just beyond the event horizon of the black hole. We are learning that you can reveal a lot about the physics of what is going on around black holes by watching them as a function of time.”
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 gathered in New Mexico with existing SDSS instruments, as 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 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.
Trump points out that another important aspect of SDSS, especially in a time of remote learning and researching, is the fact that data are made public and accessible.
“It is easy to access and mine the SDSS databases and make interesting studies,” he says. “They have wonderful tutorials for schools and for researchers to get started. They make it so easy for people to dive in. It is a very rich opportunity; it’s well organized and publicly shared.”
To learn more about the program, explore the data, or keep up with the research, visit https://www.sdss5.org/
This article first appeared online on UConn Today, November 2, 2020.
UConn graduate student Gloria Fonseca Alvarez was featured with a video in the Author Interview series produced by the American Astronomical Society (AAS):
In this video, Gloria talks about her work to understand the inner environments of black holes. The paper highlighted in the video shows that the orbits of emission-line gas around supermassive black holes are often smaller than expected from previous observations. We’re very proud to see Gloria’s exciting work recognized in the AAS Author Series!
October 12, 2020 – Kim Krieger – UConn Communications
When people imagine new materials, they typically think of chemistry. But UConn physicist Ilya Sochnikov has another suggestion: mechanics.
Sochnikov works with superconductors. Superconductors are materials that let electricity flow without losing energy. In a normal conductor — say, a power line — electric current is gradually whittled down by friction and loss. We lose as much as 90% of the electricity we generate this way. But an electric current could flow through a superconducting circuit forever, unchanging. Practical superconductors would make power grids and many devices, including new computers, much more energy efficient.
Chemists and metallurgists have experimented with different combinations of elements for years, trying to get superconductors that work at temperatures close to room temperature (most superconductors only work when they are super cold.) The idea is to come up with the perfect combination of elements that will have exactly the right density of electrons, at the right energies. When that happens, electrons pair up and move through the material in a synchronized way, even at temperatures above 77 degrees Kelvin, which is the temperature of liquid nitrogen. That is considered a high-temperature superconductor, because liquid nitrogen is cheap to produce and can be used as a refrigerant. But finding the right chemistry to make new and better high-temperature superconductors has been elusive.
Sochnikov and his students are thinking about it differently. What if mechanical changes such as squeezing or stretching could make a material a superconductor? Changing the chemistry is ultimately about changing the arrangement of atoms and electrons in a material. Mechanical stresses can do the same thing, in a different way.
Along with Physics Department students Chloe Herrera, Jonah Cerbin, Donny Davino, and Jacob Franklin, Sochnikov designed a machine to stretch a small piece of superconductor to see what would happen. They picked strontium titanate, a well-known material used in high-tech electronics applications as big and almost perfect crystals, which becomes a superconductor around 0.5 degrees Kelvin. That is ridiculously cold, colder even than liquid helium. But strontium titanate behaves in a very weird way when it is that cold. Its atoms polarize; that means they all oscillate in synchrony. You can imagine them bouncing gently up and down, all together. These oscillations have a tendency to link electrons together, helping them move as a pair–this is probably what makes it superconduct.
Sochnikov and the students in the group knew that stretching strontium titanate would change how its atoms oscillated. That, in turn, might change how the electrons moved. The machine that stretches the crystal is made from copper to conduct heat away from the crystal. Most of the rest of the workings are coated in gold to reflect heat from the outside. It uses three cylinders to cool the material; first to the temperature of liquid nitrogen (70K), then liquid helium (4K), then to a boiling mixture of helium-3 and helium-4 (due to weird quantum effects, it is even colder than regular liquid helium–just a few thousandths of Kelvin! Really close to absolute zero!)
The whole setup is suspended in a steel frame that floats on shock absorbers, to prevent any vibrations in the floor from disturbing the experiment.
When Sochnikov, Herrera, Cerbin, Davino, and Franklin did the experiment and looked at the results, they found that stretched strontium titanate becomes superconducting at temperatures 40% higher than normal. That is a huge increase, percentage-wise. They believe it is because stretching the material makes it easier for the atoms to oscillate, gluing the electrons together more firmly. Now, they are working to calculate what made the difference, and plan on testing it in other materials in the near future.
“Usually we control materials chemically. Here, we do it mechanically. This gives us another tool to bring superconductors closer to everyday life, and to discover new functionalities,” Sochnikov says.
This article first appeared online on UConn Today, October 12, 2020.
Erin Scanlon joins our Department in fall 2020 as Assistant Professor in Residence at the Avery Point Campus. Erin comes to UConn with an impressive track record of university teaching experience and scholarship in physics education research (PER).
After earning a master’s degree in physics from Georgia Institute of Technology, Erin joined the faculty at Texas Lutheran University from 2012-2017 where she developed and taught introductory physics courses and the associated labs. In parallel to that, Erin pursued PhD in the developmental education doctoral program at the Texas State University, the only program of its kind in the nation, where she earned her PhD in 2017 receiving the 2018 Texas State University Outstanding Dissertation Award. Subsequently Erin accepted a position as a preeminent postdoctoral scholar at University of Central Florida in the group of Dr. Jackie Chini. Erin is a renowned expert in the field of physics education research. Her research, supported by intra- and extra-mural grants, was published in the top PER and STEM education journals. Recently Erin’s research focused on two main streams: investigating how studio physics is implemented across multiple institutions in the nation, and investigating how to support people with disabilities in STEM fields.
Erin is one of the founding steering committee members of the APS Inclusion, Diversity, and Equity Alliance (APS-IDEA) launched by APS in summer 2020. This new APS initiative is a world-wide alliance to support departments, national labs and other institutions to identify and enact strategies for improving equity, diversity and inclusion which is much needed in physics. APS-IDEA is a great success with currently more than 90 admitted teams including UConn, see the article on APS-IDEA (to avoid conflict of interest our application was not reviewed by Erin). Erin is also the vice chair of the Physics Education Research Leadership and Organizing Council (PERLOC) which is the leadership body for the physics education research community and founded the Conference Accessibility Working Group.
Erin is committed to outreach and initiated at the Texas Lutheran University highly successful outreach events, called Family Physics Night, which brought together members from the university and local community members. Once settled in, Erin is looking forward to start similar outreach and research activities. Erin moved to Connecticut with her husband Matt who is also a scholar in PER and teaches physics at post-secondary level. We are excited to welcome Erin as a physics faculty in our department, and look forward to working with her.
We are very excited to extend a warm welcome to a new UConn Physics Faculty member, Dr. Christopher Faesi. Chris is an astrophysicist, specializing in both observational work and modelling, primarily in the study of star formation. He got his PhD at Harvard University, followed by a postdoc at the Max Planck Institute for Astronomy in Heidelberg. Most recently Chris was awarded a prestigious NSF Postdoctoral Fellowship at UMass Amherst, and will be on research leave this academic year, completing this Fellowship. Chris is heavily involved in several large-scale international collaborations that will probe the physics of the interstellar medium in nearby galaxies with unprecedented resolution and spectral coverage. He also has extensive experience leading mentorship and outreach activities devoted to students at all levels, as well as the general public. We are looking forward to welcoming Chris to UConn!
Kyungseon Joo, a professor of physics, has been named Chair of the CLAS Collaboration, one of the largest international collaborations in nuclear physics. CLAS involves 50 institutions from 9 countries and has about 250 collaborators. The collaboration recently completed the upgrade of the CEBAF Large Acceptance Spectrometer (CLAS12) for operation at 11 GeV beam energy in Hall B at Jefferson National Laboratory in Newport News, VA, funded by the United States Department of Energy.
CLAS12 is based on a dual-magnet system with a superconducting torus magnet that provides a largely azimuthal field distribution that covers the forward polar angle range up to 35°, and a solenoid magnet and detector covering the polar angles from 35° to 125° with full azimuthal coverage. Trajectory reconstruction in the forward direction using drift chambers and in the central direction using a vertex tracker results in momentum resolutions of 1% and 3%, respectively. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 1035 cm−2s−1. These capabilities are being used in a broad scientific program to study the structure and interactions of nucleons, nuclei, and mesons, using polarized and unpolarized electron beams and targets for beam energies up to 11 GeV.
As Chair, Joo represents the collaboration in scientific, technical, and managerial concerns, while he closely works with the Lab management on scheduling experiments, organizing collaboration activities and expanding the reach of the collaboration. He currently focuses on collaboration-wide efforts to timely make first publications from CLAS12 with high impact science.
The CLAS12 detector in the Hall B beamline. The beam enters from the right near the upstream end of the solenoid magnet and the cryogenic service tower, followed by the High Threshold Cherenkov Counter and the torus magnet with the drift chambers. The Low Threshold Cherenkov Counter, Forward Time-of-Flight, and the electromagnetic calorimeters are seen at the downstream end to the left.
Assistant Professor of Physics Luchang Jin has been chosen to receive a prestigious Early Career Award from the US Department of Energy’s Office of High Energy Physics (HEP) for 2020. The amount of the award is $750,000 to be used over five years. The DOE Early Career Award is extremely competitive: this year only 16 scientists in HEP in the US were awarded such grants, and only 76 scientists across the entire DOE. Dr. Jin will use the grant to support his research using numerical methods to study how electromagnetic interactions affect the decays of mesons, subatomic particles composed of a quark and anti-quark pair. This study, carried out within the framework of the fundamental Standard Model of Particle Physics, is expected to improve our knowledge of the interactions between quarks and the Weak gauge bosons. With some luck, Professor Jin’s research may provide evidence of new interactions or particles yet to be discovered.
Jonathan Trump, Assistant Professor of Physics, will receive $738,090 over five years to compile a census of supermassive black holes in the universe. This will give insights into how supermassive black holes and galaxies evolve across cosmic time. Trump will also develop a bridge program for underrepresented undergraduate physics majors at UConn to increase their participation in STEM fields.
The NSF Faculty Early Career Development (CAREER) Program supports 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. Activities pursued by early-career faculty build a firm foundation for a lifetime of leadership in integrating education and research.
Trump was one of 7 junior faculty at the University of Connecticut to receive the prestigious Early Career awards from NSF in 2020. For a description of all 7 awards, seethis recent article published in UConn Today.
Jonathan Trump, Assistant Professor of Physics, will receive