News and Events

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Bard College Astronomer Shuo Zhang and Undergraduate Student Rose Xu Discover New X-ray Flares from the Galactic Center Supermassive Black Hole Sgr A*

Bard College Assistant Professor of Physics Shuo Zhang and Bard mathematics and dance major Rose Xu ’23 were invited by the American Astronomical Society (AAS) to present their most recent findings on new x-ray flares from the now inactive supermassive black hole at the center of our Milky Way galaxy. Their talk, “Detection of Seven High-Energy X-ray Flares from the Milky Way’s Supermassive Black Hole,” was presented at the 241st AAS press conference on Thursday, January 12 from 5:15pm to 6:15pm ET, in person in Seattle and virtually via Zoom and YouTube livestream. For more information about the 241st AAS press conference, click here.

The center of the Milky Way galaxy harbors the nearest supermassive black hole Sgr A* to Earth, with forty million times the mass of the Sun. Although being in an inactive status nowadays, Sgr A* demonstrates mysterious flares almost every single day, which could come from magnetic phenomena. We are sitting in the front row of these cosmic fireworks. Using 2 Ms data from NASA’s NuSTAR X-ray telescope, our math senior Rose Xu, working with Bard physics professor Shuo Zhang, has discovered seven new hard X-ray flares that took place between 2016 and 2022. This new result doubled the current database of bright Sgr A* X-ray flares, and can help to answer long-standing questions in flare physics, such as: What are the physical mechanisms behind Sgr A* flare? Do bright flares and faint flares share the same origin? 

Watch the Presentation at the American Astronomical Society Press Conference

“Astronomers are in the exhilarating process of revealing the physical conditions at the vicinity of our own supermassive black hole, which I couldn’t imagine myself being involved in before meeting professor Shuo Zhang. Solving practical problems from a liberal arts perspective is a skill that I am grateful to gain here at Bard College,” said Xu.
 

Post Date: 01-17-2023

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Bard Physics Professor Clara Sousa-Silva Coauthors New Research on How the James Webb Space Telescope Impacts Our Understanding of Planetary Atmospheres

Bard College Assistant Professor of Physics Clara Sousa-Silva has published a new study, “The impending opacity challenge in exoplanet atmospheric characterization,” in the peer-reviewed journal Nature Astronomy. The paper is led by graduate student Prajwal Niraula (MIT), and coauthored by Julien de Wit (MIT), Iouli E Gordon (Harvard), Robert Hargreaves (Center for Astrophysics | Harvard & Smithsonian), Clara Sousa-Silva (Bard), and Roman Kochanov (Center for Astrophysics | Harvard & Smithsonian). Their research suggests that the current tools astronomers use to analyze data received from space telescopes may not be precise enough to accurately decode the unprecedented clarity of light-signals captured through next-generation observatories, including the extremely powerful James Webb Space Telescope (JWST) launched by NASA in December 2021. 

“We find ourselves in the extraordinary situation where the incredible engineering of JWST has resulted in the data collected from distant planets outcompeting our ability to interpret what we are seeing,” says Sousa-Silva. 

Astronomers rely on ‘opacity models,’ which interpret how matter interacts with light, to describe and predict the physical properties of astronomical objects. This new study used existing opacity models to analyze spectral data collected from JWST and to look at the characterization of exoplanetary atmospheres—predicting atmospheric temperature, pressure, and elemental composition. The researchers warned that for each possible atmospheric signal from an exoplanet, multiple interpretations could be made with current models and fundamental molecular inputs. The imprecision from these models means that data from an alien atmosphere could be misinterpreted. The implications of such misinterpretations include our understanding of whether an exoplanet could support life or not.

“There is a scientifically significant difference between a compound like water being present at 5 percent versus 25 percent, which current models cannot differentiate,” says study coauthor Julien de Wit.

The authors show how the limits of our knowledge on light–matter interactions (i.e. opacity models) will affect our exploration of exoplanetary atmospheres. “Accounting for these limits will prevent biased claims,” they write. “Guided improvements in opacity models, their standardization and dissemination will ensure maximum return on investment from the next-generation observatories, including the James Webb Space Telescope.” Their findings call for an investment in improved laboratory and theoretical data on atmospheric molecules, and development of more precise opacity models.

Post Date: 09-18-2022

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Bard Physics Professor Shuo Zhang Receives NASA Grant for Research on Galactic Center Supermassive Black Hole Sgr A*

Bard College Assistant Professor of Physics Shuo Zhang has received a $91,933 grant from the National Aeronautics and Space Administration (NASA) in support of her investigation, “Joint NuSTAR and EHT Probe of SgrA*: Flares, Black Hole Shadows, a New Hard X-Ray Source.” The NASA grant supports Zhang’s investigation, which includes the engagement of a postdoctoral researcher, three undergraduate research assistants, equipment, and travel. As the joint observation involves the international Event Horizon Telescope (EHT) collaboration, coinvestigators on this project come from around the globe including Canada, the Netherlands, and Japan. 

NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) is a space telescope that detects high-energy X-ray light and studies some of the most energetic objects and processes in the universe. The Event Horizon Telescope (EHT) is an international collaboration capturing images of black holes using a virtual Earth-sized telescope. Zhang’s investigation proposes an observation of Sgr A*, the now inactive supermassive black hole at the center of our Milky Way galaxy. This research aims to capture bright X-ray flares from Sgr A* and feed this result to the EHT analysis. A secondary goal is to study a mysterious X-ray source located at merely three light years from Sgr A*.

“Among all the fascinating science one can pursue via a joint X-ray and EHT observations of our own supermassive black hole, the physics behind mysterious daily Sgr A* flares is the jewel in the crown that astronomers have been pursuing. I am proud of our own students, physics major Nathalie Jones ’21, dance and mathematics major Rose Xu ’23, and physics major Grace Sanger-Johnson ’23, who have contributed to this exciting project.” says Zhang.

This NASA grant supports the training and involvement of three Bard undergraduate research assistants who will work on the preparation and analysis of the new data during the summer of 2023. Under Zhang’s supervision, the Bard students will study NuSTAR data analysis pipeline, X-ray spectral and image analysis softwares, and will contribute to data preparation.

Since 2019, Zhang has received five grants from NASA for her astrophysics research, totaling more than $331,000 in NASA funding to date.

Post Date: 08-08-2022

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Bard College Assistant Professor of Physics Antonios Kontos Receives $210,000 Grant from the National Science Foundation to Support Research in Measuring Gravitational Waves

Bard College has received a $210,000 grant from the National Science Foundation (NSF) in support of Assistant Professor of Physics Antonios Kontos’s proposal “Research in Light Scattering Metrology for Gravitational Wave Optics.” The three-year NSF grant supports his continuing research, summer research assistants, and equipment. All research projects are to be carried out with the engagement of Bard undergraduate and local area high school students, who will be hired as summer research assistants, and provide opportunities to gain invaluable experience in pursuing careers in technology and academia.

“This NSF grant will ensure that Bard continues to contribute to the fascinating new field of gravitational wave astronomy and that our students will continue to engage in cutting edge research in optics,” says Kontos.

The NSF award supports Kontos’s research in gravitational wave (GW) detector instrumentation, one of the most important leaps in scientific progress in recent years. The Laser Interferometer Gravitational-wave Antenna (LIGO) project has given scientists the ability to observe the universe in a completely new way. Unlike conventional telescopes which use the light emitted by stars and galaxies to learn their properties and their place in the universe, GW detectors use gravitational waves which are similarly emitted by many astrophysical objects.

Gravitational-waves are ripples in spacetime that travel to Earth, and cause the detectors to essentially change in size. To do that, the LIGO detectors require state-of-the-art mirrors, which are used to sense the stretching of space. Improvements in mirror design will allow observers to look further into space, and detect more of these GW signals. 

Kontos’s proposed project will aid in pushing the mirror technology, by utilizing light scattering as a tool to study mirror coatings. Specifically, an important aspect of mirror quality is the presence of defects which scatter light and inhibit the operation of the LIGO detectors. Defects may sometimes develop on the mirror surface with time, but the process is not always understood. This research project is designed to study defects on mirrors so that we can ultimately improve LIGO’s sensitivity and improve our understanding of space, time, matter, energy, and their interactions. 

Post Date: 06-07-2022

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Bard College Appoints Beate Liepert as Visiting Professor of Environmental and Urban Studies and Physics in the Division of Science, Mathematics, and Computing

Bard College’s Division of Science, Mathematics, and Computing is pleased to announce the appointment of Beate Liepert as Visiting Professor of Environmental and Urban Studies and Physics. Professor Liepert, who joined the Bard faculty in January 2022, focuses on environmental physics, with a specific research goal of pursuing local solutions to the global issue of climate change. Her research interests include micrometeorology, air pollution, and community-based science.

Dr. Beate Liepert is a climate scientist who pioneered research on the phenomenon of “global dimming,” a decline in the amount of sun reaching the Earth’s surface, which has implications on the planet’s water and carbon cycles. She comes to Bard from the Seattle area, where she worked for and founded start-ups in the clean tech and insure tech fields, and was a lecturer in the Department of Civil and Environmental Engineering at Seattle University. The start-ups included CLIWEN LLC, a climate, energy, and weather consulting concern; and Lumen LLC, a company that developed design solutions for solar cells. She also served as a research scientist at True Flood Risk LLC in New York, NorthWest Research Associates in Seattle, and the Lamont-Doherty Earth Observatory of Columbia University. Her work centers on basic questions of climate variability, from interannual to centennial time scales. Research interests also include taking measurements of aerosols and solar radiation and investigating climate effects on ecosystems.

Additional activities have included serving as editor for Environmental Research Letters, a UK-based journal; proposal review panelist and proposal reviewer for the National Science Foundation; presenting at more than 50 international conferences and university colloquia; and authoring reviews and articles for journals including Bulletin of the American Meteorological Society, Climate, Frontiers, International Journal of Climatology, Nature, Science, Quarterly Journal of the Royal Meteorological Society, and Global and Planetary Change, among many others. She has been interviewed on CNN and numerous international TV broadcasts; was a featured scientist in the BBC documentary Dimming the Sun, which also aired on PBS; and was profiled in a “Talk of the Town” essay in the New Yorker. Professor Liepert is the recipient of the 2016 WINGS World Quest “Women of Discovery” Earth Award and in 2015 she delivered a Distinguished Scientist Lecture at Bard on “Dimming the Sun: How Clouds and Air Pollution Affect Global Climate.”

Diploma, Institute of Meteorology and Institute of Bioclimatology and Air Pollution Research, Ludwig-Maximilians University Munich; Doctor rer. nat., Institute of Meteorology, Department of Physics, Ludwig-Maximilians University; postdoctoral research scientist, Lamont-Doherty Earth Observatory of Columbia University; certificate program in fine arts, Parsons School of Design.

Post Date: 04-13-2022

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Bard Physics Professor Shuo Zhang Presents Research on Supermassive Black Hole at 2022 American Astronomical Society Press Conference

Bard College Assistant Professor of Physics Shuo Zhang has been invited by the American Astronomical Society (AAS) to present her most recent research on how surrounding molecular gas clouds offer insight into the activity history of Sgr A*, the now inactive supermassive black hole at the center of our Milky Way galaxy. Zhang’s talk, “Galactic Center Molecular Clouds: Storytellers of Past Outburst of the Galactic Center Supermassive Black Hole,” is being presented at a virtual AAS press conference to be held on Tuesday, January 11 from 4:15pm to 5:15pm ET via Zoom. For more information about the virtual press conference, click here.

Though inactive nowadays, traces of a glorious past of Sgr A* can be found in the surrounding molecular gas clouds, which reflect incoming X-ray emission from Sgr A* up to a few hundred years ago. Therefore, by studying X-ray emission from molecular clouds at different distances from Sgr A*, we can reconstruct the activity history of Sgr A* in the past few centuries. Shuo Zhang and her post-bac researcher Nathalie Jones ’21 have focused their study on a particular Galactic center molecular cloud, the “Bridge”. Their analysis on archival data by the NuSTAR telescope during 2012-2020, and the XMM-Newton telescope data during 2000-2020 clearly demonstrates an epic 20-year-long X-ray brightening of the “Bridge” molecular cloud, making it currently the brightest diffuse feature in the Sgr A* complex region. Continuous monitoring of this molecular cloud and capturing its peak luminosity will tell us how luminous Sgr A* used to be a couple dozen years ago, which is essential to understand the activity cycle of supermassive black holes. This project is supported by NASA NuSTAR Guest Observation grant #80NSSC20K0035.

“It is amazing to have these molecular gas clouds as storytellers of past activities of the monster black hole in the center of our Galaxy,” says Zhang. 

About the Annual Conference of the American Astronomical Society
The American Astronomical Society is the major organization of professional astronomers in North America, with a membership of 7,700 individuals with research and educational interests in astronomical sciences. The 239th meeting is the 2022 winter annual American Astronomical Society conference, which brings together the International astronomer community and shares the most recent discoveries and results in astronomy. Though the major meeting was canceled due to COVID situation, the press conference will take place virtually as planned.

Post Date: 01-11-2022