Institute for Gravitation and the Cosmos

2023-04-25

Cody Messick, who earned a doctorate in physics from Penn State in 2019, was honored with the Northeastern Association of Graduate Schools’ 2023 Doctoral Dissertation Award. The annual award recognizes one outstanding dissertation that has been produced by a doctoral candidate at one of its member institutions. “It's exciting and incredibly validating to receive an award like this,” said Messick, now a postdoctoral researcher at the Massachusetts Institute of Technology. “I set out to write my dissertation from scratch instead of combining papers, because I wanted more control over the way I presented the story of my research. Receiving an award like this makes that effort feel seen, and, while I originally took the route, I did it for myself, and it's an honor to receive recognition for it.” Messick’s pioneering research focused on gravitational waves, which are ripples in space that were first hypothesized by Albert Einstein. Messick’s work led to the first-ever discovery in 2015 of gravitational waves using a highly sophisticated measurement device known as the Laser Interferometer Gravitational-Wave Observatory (LIGO), which uses lasers to measure miniscule changes in space occurring from distant astronomy events, such as a supernova. Today, LIGO and similar gravitational-wave detectors are used by an international research team, known as the LIGO-Virgo-KAGRA Collaboration, that is led, in part, by Penn State researchers. For his doctoral dissertation, “Detecting Gravitational Waves for Multi-Messenger Astronomy,” Messick developed algorithms for sifting through large amounts of data produced by LIGO to identify subtle signals of a distant astronomical event. Messick’s innovations led to the identification of 11 separate gravitational wave signals, as well as the ability to detect signals in real time. “The most exciting of these detections occurred on Aug. 17, 2017. I was the first person in the world to see that our analysis had identified a signal that went through our detectors within two seconds of an extremely energetic burst of electromagnetic radiation called a gamma-ray burst. We were able to confirm that these two events came from the same astrophysical source: two neutron stars colliding roughly 130 million light-years away,” said Messick. This work was recognized as Science’s Breakthrough of the Year in 2017. Messick’s work helped to pave the way for LIGO’s data to be an integral part of multi-messenger astronomy, which leverages signals from different sources, such as neutrinos and electromagnetic waves, to create a deeper understanding of the universe. “Gravitational wave astronomy is now a bona fide field of physics due, in no small measure, to the contributions of Cody Messick while he was a graduate student at Penn State, working on the Laser Interferometer Gravitational-Wave Observatory (LIGO),” said Doug Cowen, professor of physics and astronomy and astrophysics at Penn State. “His analysis techniques were central to the detection and subsequent localization of the first triply-detected gravitational wave, followed very shortly afterward by the first binary neutron star merger discovery, which led directly to the first coincident gravitational wave plus gamma-ray detection. Together, these momentous discoveries have elevated gravitational waves to a preeminent position in the nascent field of multi-messenger astronomy.”

2023-04-25

Miguel Alejandro Mostafá, professor of physics and of astronomy and astrophysics and associate dean for research and innovation in the Eberly College of Science, is one of five Penn State faculty members to receive a 2023 Faculty Scholar Medal for Outstanding Achievement. Established in 1980, the award recognizes scholarly or creative excellence represented by a single contribution or a series of contributions around a coherent theme. A committee of peers reviews nominations and selects candidates. Nominators said Mostafá has significantly advanced the frontiers of fundamental knowledge regarding particle physics and astrophysics. That’s opened unprecedented windows into the physics of our universe. Mostafá is an experimental particle astrophysicist who researches the origins of the most energetic particles in the Universe. Mostafá uses cosmic messengers in the form of ultrahigh energy cosmic and gamma rays to probe the physics behind cosmic accelerators. He earned the Faculty Scholar Medal in Physical Sciences. Mostafá conducts this work through international collaborations at the High Altitude Water Cerenkov Gamma-Ray Observatory (HAWC) in Mexico and the Pierre Auger Observatory in Argentina. “Rising to prominence as a scientist in large physics collaborations such as HAWC or Auger is not an easy endeavor,” a nominator said. “It requires both keen scientific talent and managerial acumen for complex project management.” At HAWC, Mostafá’s team oversaw the construction of important components of the observatory. His team also produced various analytical tools that led to the discovery of new gamma-ray sources and the most powerful accelerators in our galaxy. At Auger, Mostafá steered the hardware design and construction and also had a hand in software, analysis and interpretation. Nominators said his background in physics and astrophysics meant he could be the bridge to cross historical boundaries between particle physics and high-energy astrophysics. At Penn State, Mostafá helped create the Astrophysical Multimessenger Observatory Network (AMON) by serving as principal investigator for the first NSF-funded grant — which was subsequently renewed — on multi-messenger astrophysics. Mostafá oversees several areas of AMON, including oversight of technology solutions, organizing workshops and international partnerships. “AMON placed Penn State on the international map in this field by pioneering searches that combine signals from various cosmic sources,” a nominator said. “In the past few years, AMON has made major discoveries by combining observations from various observatories. That led to the landmark observation of a ‘flaring blazar’ in coincidence with high energy neutrinos. That discovery was a direct result of Mostafá’s leadership.” Mostafá is now working on the Giant Radio Array for Neutrino Detection, which nominators say will lead to new discoveries related to multi-messenger astrophysics. “Mostafá has all the characteristics that embody a true ‘faculty scholar,’” a nominator said. “He is a scientific leader, an inspiring teacher and mentor, and a citizen-scientist contributing energetically to the academic enterprise and to the scientific awareness in broader society.”

2023-04-25

On Sunday, Oct. 9, 2022, a pulse of intense radiation swept through the solar system. It was so exceptional that astronomers quickly dubbed it the "BOAT"—the brightest of all time. The source was a gamma-ray burst (GRB), the most powerful class of explosions in the universe. The burst triggered detectors on numerous spacecraft, including the Neil Gehrels Swift Observatory, whose Mission Operations Center is located at Penn State. “When we first detected the burst, it was so bright and so close that we didn’t actually think it was a gamma-ray burst,” said Maia Williams, a research technologist at Penn State and a member of the Swift team. “But observations from NASA’s Fermi Gamma-ray Space Telescope and other observatories confirmed that this was indeed from a uniquely bright gamma-ray burst.” After the initial detections, observatories around the globe followed up. After combing through all of this data, astronomers can now characterize just how bright it was and better understand its scientific impact. “GRB 221009A was likely the brightest burst at X-ray and gamma-ray energies to occur since human civilization began,” said Eric Burns, an assistant professor of physics and astronomy at Louisiana State University in Baton Rouge. He led an analysis of some 7,000 GRBs detected by various observatories to establish how frequently events this bright may occur. Their answer: once in every 10,000 years. Burns and other scientists presented new findings about the BOAT at the High Energy Astrophysics Division meeting of the American Astronomical Society in Waikoloa, Hawaii. Papers describing the results presented—including one describing Swift’s initial detection—will appear in a focus issue of The Astrophysical Journal Letters. The signal from GRB 221009A had been traveling for about 1.9 billion years before it reached Earth, making it among the closest known “long” GRBs, whose initial, or prompt, emission lasts more than two seconds. Astronomers think these bursts represent the birth cry of a black hole that formed when the core of a massive star collapsed under its own weight. As it quickly ingests the surrounding matter, the black hole blasts out jets in opposite directions containing particles accelerated to near the speed of light. These jets pierce through the star, emitting X-rays and gamma rays as they stream into space. As the jets continue to expand into space, they produce a multiwavelength afterglow that gradually fades away. William’s team found that the afterglow was more than 10 times brighter than that of any previous gamma-ray bursts observed by Swift. In many cases, the exploding star also propels debris and other matter into space in a supernova, which should be detectable on Earth a few weeks after the initial GRB. There has been some debate amongst astronomers as to whether this supernova occurred, or if the star instead collapsed straight into the black hole without exploding. One reason the supernova has been challenging to detect is because the GRB occurred just a few degrees above the plane of our own galaxy, where thick dust clouds can greatly dim incoming light. However, using the sensitive Pan-STARRS optical ground telescope, the Young Supernova Experiment collaboration was able to spot the supernova. “Pan-STARRS observations uniquely allowed us to see deeper in the redder part of the optical spectrum, which allowed us to see the supernova,” said V. Ashley Villar, Mercedes Richards Career Development Professor of Astronomy and Astrophysics, co-hire of the Institute for Computational and Data Sciences at Penn State and a member of the Young Supernova Experiment collaboration. “Our team plans to use the James Webb Telescope to further investigate the supernova and search for signatures of heavy element formation.” The burst also enabled astronomers to probe distant dust clouds in our own galaxy. As the prompt X-rays traveled toward us, some of them reflected off of dust layers, creating extended “light echoes” of the initial blast in the form of X-ray rings expanding from the burst’s location. Swift’s X-ray telescope discovered the presence of a series of echoes. Detailed follow-up by the European Space Agency’s XMM-Newton telescope, together with Swift data, revealed these extraordinary rings were produced by 21 distinct dust clouds. “How dust clouds scatter X-rays depends on their distances, the sizes of the dust grains, and the X-ray energies,” explained Sergio Campana, research director at Brera Observatory and the National Institute of Astrophysics in Merate, Italy. “We were able to use the rings to reconstruct part of the burst’s prompt X-ray emission, and also to determine where in our galaxy the dust clouds are located.” GRB 221009A is only the seventh gamma-ray burst to display X-ray rings, and it triples the number previously seen around one. The echoes came from dust located between 700 and 61,000 light-years away. The most distant echoes—clear on the other side of our Milky Way galaxy—were also 4,600 light-years above the galaxy’s central plane, where the solar system resides. This extraordinary gamma-ray burst helps provide a deeper understanding of how stars collapse and how black holes are born. “This once in a lifetime event gave us a unique opportunity to study the death throes of a massive star in incredible detail,” said Jamie Kennea, research professor of astronomy and astrophysics at Penn State who leads the Swift Science Operations Team. “Thankfully, astronomers from around the world answered our call to arms, and the results have been amazing.”

5th IGC Neighborhood Workshop held in State College

2023-04-07

The 5th Annual IGC Neighborhood Workshop, an event for physicists in the local region around Penn State, was held downtown and in the Alumni Center. Faculty, postdocs and grad students, many from Penn State, gave brief talks and interacted with other groups in the immediate vicinity (A ~three hour drive) of State College. Participants included physicists from: Carnegie Mellon University Case Western Reserve University CMU Cornell University Johns Hopkins University Lehigh University Penn State University Space Telescope Science Institute Syracuse University University at Buffalo University of Pennsylvania University of Pittsburgh West Virginia University Thank you to everyone who came out!

IGC Art Exhibition Showcases Institute's Artists

2023-03-30

IGC members met in 321 Whitmore to showcase their works, from posters, to instruments and interactive displays. Special thanks is given to Monica Rincon Ramirez for helping to organize. An art booklet will be printed soon, and thanks again to everyone who brought their art to show off!

2023-03-21

IGC grad student Rachael Huxford, a science communication intern for the Eberly College of Science, conducted an interview with two 'I AM STEM' winners. The I AM STEM speaking contest was designed to help Penn State's Eberly College of Science students develop and share stories of their science journey. Winners of the contest have been keynote speakers at the college’s annual ENVISION: STEM Career Day Supporting Young Women event where they have been able to inspire other burgeoning STEM minds. Other contest objectives include developing science communication abilities and identifying and showcasing Eberly College of Science students with inspiring, authentic STEM stories. Additional fall 2022 participants included Eberly College of Science undergraduate students Basma AlMahmood, Ariella Biney, and Emma Khoury, and the IGC's own graduate student Unnati Akhouri.

2023-02-27

In 1974, Cambridge University Press published the celebrated monograph Large Scale Structure of Space-time which was immediately hailed as “a masterpiece, written by sure hands” in the book review section of Science. For its 50th anniversary edition, CUP invited Abhay to write a Foreword to put this work in the context of the subsequent developments over the last 5 decades. See the PDF file Of the Foreword:

2023-02-23

Six massive galaxies discovered in the early universe are upending what scientists previously understood about the origins of galaxies in the universe. “These objects are way more massive​ than anyone expected,” said Joel Leja, assistant professor of astronomy and astrophysics at Penn State, who modeled light from these galaxies. “We expected only to find tiny, young, baby galaxies at this point in time, but we’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.” Using the first dataset released from NASA's James Webb Space Telescope, the international team of scientists discovered objects as mature as the Milky Way when the universe was only 3% of its current age, about 500-700 million years after the Big Bang. The telescope is equipped with infrared-sensing instruments capable of detecting light that was emitted by the most ancient stars and galaxies. Essentially, the telescope allows scientists to see back in time roughly 13.5 billion years, near the beginning of the universe as we know it, Leja explained. “This is our first glimpse back this far, so it's important that we keep an open mind about what we are seeing,” Leja said. “While the data indicates they are likely galaxies, I think there is a real possibility that a few of these objects turn out to be obscured supermassive black holes. Regardless, the amount of mass we discovered means that the known mass in stars at this period of our universe is up to 100 times greater than we had previously thought. Even if we cut the sample in half, this is still an astounding change. In a paper published today (Feb. 22) in Nature, the researchers show evidence that the six galaxies are far more massive than anyone expected and call into question what scientists previously understood about galaxy formation at the very beginning of the universe. “The revelation that massive galaxy formation began extremely early in the history of the universe upends what many of us had thought was settled science,” said Leja. “We’ve been informally calling these objects ‘universe breakers’ — and they have been living up to their name so far.” Leja explained that the galaxies the team discovered are so massive that they are in tension with 99% of models for cosmology. Accounting for such a high amount of mass would require either altering the models for cosmology or revising the scientific understanding of galaxy formation in the early universe — that galaxies started as small clouds of stars and dust that gradually grew larger over time. Either scenario requires a fundamental shift in our understanding of how the universe came to be, he added. “We looked into the very early universe for the first time and had no idea what we were going to find,” Leja said. “It turns out we found something so unexpected it actually creates problems for science. It calls the whole picture of early galaxy formation into question.” On July 12, NASA released the first full-color images and spectroscopic data from the James Webb Space Telescope. The largest infrared telescope in space, Webb was designed to see the genesis of the cosmos, its high resolution allowing it to view objects too old, distant or faint for the Hubble Space Telescope. “When we got the data, everyone just started diving in and these massive things popped out really fast,” Leja said. “We started doing the modeling and tried to figure out what they were, because they were so big and bright. My first thought was we had made a mistake and we would just find it and move on with our lives. But we have yet to find that mistake, despite a lot of trying.” Leja explained that one way to confirm the team’s findings and alleviate any remaining concerns would be to take a spectrum image of the massive galaxies. That would provide the team data on the true distances, and also the gasses and other elements that made up the galaxies. The team could then use the data to model a clearer picture of what the galaxies looked like, and how massive they truly were. “A spectrum will immediately tell us whether or not these things are real,” Leja said. “It will show us how big they are, how far away they are. What’s funny is we have all these things we hope to learn from James Webb and this was nowhere near the top of the list. We’ve found something we never thought to ask the universe — and it happened way faster than I thought, but here we are.” The other co-authors on the paper are Elijah Mathews and Bingjie Wang of Penn State, Ivo Labbe of the Swinburne University of Technology, Pieter van Dokkum of Yale University, Erica Nelson of the University of Colorado, Rachel Bezanson of the University of Pittsburgh, Katherine A. Suess of the University of California and Stanford University, Gabriel Brammer of the University of Copenhagen, Katherine Whitaker of the University of Massachusetts and the University of Copenhagen, and Mauro Stefanon of the Universitat de Valencia.

Abhay Ashtekar was named Atherton Professor

2023-02-14

Congratulations to Dr. Abhay Ashtekar, who has been named Atherton Professor. This position recognizes Emeritus Evan Pugh Professors for their exceptional record in the scholarship of research, teaching, and service over the course of their careers.

2023-02-09

The Eberly College of Science Climate and Diversity Committee has selected three individuals and one group to receive 2022 Climate and Diversity Awards in recognition of their extraordinary commitment to enhancing the environment of mutual respect and diversity in the college over the past year. The award is supported by the Santacroce Family Climate and Diversity Fund in the Eberly College of Science. The awardees and nominees were honored at an annual ceremony on Thursday, January 16, 2023, to recognize their efforts to make our college community supportive and welcoming to everyone. The CalBridge program— initiated at Cal Poly Pomona—aims to increase the diversity of physics practitioners by identifying and assisting members of groups historically underrepresented in physics, including by connecting students with Ph.D. programs. With guidance from the Physics Department’s CalBridge program leadership committee, Penn State is one of a handful of universities outside of California to welcome CalBridge participants to its graduate program. The leadership committee includes Stephanie Wissel, Downsbrough Early Career Assistant Professor of Physics and of Astronomy and Astrophysics; Nathan Keim, associate research professor of physics; and David Radice, assistant professor of physics and of astronomy and astrophysics. The committee prepares recruiting materials for the program, tracks applicants through the admissions process, and provides feedback about all applicants at the end of the process. It also helps to support these students’ progress once they are at Penn State. “This feedback is important to the program and future students in making sure that they understand what we are looking for in applicants, but it has also generated important discussions with the admissions committee about how to equitably evaluate applications,” said a nominator. “After just two years with the program, it has already become a major part of our efforts to diversify the Physics Department’s graduate program.”

2023-02-09

The Charles E. Kaufman Foundation—a supporting organization of The Pittsburgh Foundation, which works to improve the quality of life in the Pittsburgh region—has selected three researchers from the Eberly College of Science to receive research grants this year. The foundation awards grants to scientists at institutes of higher learning in Pennsylvania who are pursuing research that explores essential questions in biology, physics, and chemistry, or that crosses disciplinary boundaries. Ashley Villar, assistant professor of astronomy and astrophysics and co-hire of the Institute for Computational and Data Sciences at Penn State, was selected to receive a New Investigator grant for her project titled “Unveiling the Final Days of Stellar Life Through Exotic Explosions.” New Investigator grants empower scientists at the beginning of their careers who seek to make a mark in their fields and address core principles in biology, physics, and chemistry or across the disciplinary boundaries of these field. Villar will study a rare type of supernova—the explosive death of a star—called a Type IIn supernova. Prior to these rare supernovae, the star produces a “death throe” for months to years before its ultimate explosion, ejecting a considerable amount of material that then surrounds the star and that becomes shock heated during the supernova. Villar will combine techniques from high energy physics, machine learning, and statistics to analyze these events and improve our understanding of why only some stars experience this phenomenon.