NASA Hubble Fellowship Program 2020 Fellows
Host Institution: Princeton University
Proposal Title: Sub-GeV Dark Matter: Novel Models and Detection Strategies Using Molecular Targets
Carlos Blanco was born in Bogotá, Colombia and grew up in south Florida. He received degrees in chemistry and physics from Purdue University and completed his master's degree at the University of Chicago. He will complete his PhD in physics at the University of Chicago in June 2020, advised by Dr. Dan Hooper.
During his graduate career as an NSF-GRFP fellow, Carlos focused his research on high-energy particle and astroparticle phenomenology, specifically as it relates to dark matter (DM) and beyond standard-model physics. He has studied and constrained DM models, proposed detection strategies which can probe DM and sterile neutrinos, and developed tools to understand gamma-ray propagation in order to predict astrophysical particle production and DM observables
As an Einstein Fellow, his research will deal with direct detection as well as astrophysical searches for dark matter. Carlos will develop a formalism which describes the interaction of light DM with a variety of molecular and mesoscopic systems. Once Carlos confirms a formalism with which to propose new detection strategies, he will work on predictive DM models testable with the proposed techniques.
Host Institution: Massachusetts Institute of Technology
Proposal Title: Cosmology and Astrophysics with Gravitational Waves from Stellar-Mass Compact Binary Mergers
Hsin-Yu Chen grew up in Taipei, Taiwan. She received her bachelor's degree in physics from National Taiwan University. She then moved to the University of Chicago for her PhD in astronomy and astrophysics. Currently, Hsin-Yu is a postdoctoral fellow at Black Hole Initiative, Harvard University.
Hsin-Yu's research focuses on gravitational-wave cosmology and astrophysics. With Advanced LIGO-Virgo's gravitational-wave detection of compact binary mergers, Hsin-Yu is trying to answer the question of how old the Universe is—one of the biggest mysteries in cosmology. In addition, Hsin-Yu is helping to capture electromagnetic signals from LIGO-Virgo's binary mergers, so that the joint detections can shed light on the origin of the heavy elements in the universe. Finally, the mergers of neutron stars observed by LIGO-Virgo will teach us how matter behaves at low-temperature and high-density environments—another question Hsin-Yu is trying to study.
H. Thankful Cromartie
Host Institution: Cornell University
Proposal Title: Fundamental Physics with Millisecond Pulsars
Thankful Cromartie was born and raised in Chapel Hill, North Carolina, and received her BS with highest honors in physics from the University of North Carolina at Chapel Hill. She has pursued her PhD work as a graduate student in the University of Virginia's Department of Astronomy, where she currently works under the supervision of Dr. Scott Ransom as a National Radio Astronomy Observatory Grote Reber doctoral fellow. She will be defending her PhD in April 2020.
Thankful's research focuses on using millisecond pulsar (MSP) timing to explore fundamental physics. She is a member of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration, whose goal is to detect low-frequency gravitational waves from supermassive black hole binaries with an array of precisely timed MSPs. As a graduate student, she has explored topics under the NANOGrav umbrella, including the discovery of new MSPs for inclusion in the array using the Arecibo and Green Bank radio telescopes. Thankful has also worked on constraining the poorly understood neutron star interior equation of state using pulsar-timing observations of relativistic Shapiro delay. As an Einstein fellow at Cornell, she will continue to work within NANOGrav, pursuing ambitious searches for MSPs and using the full extent of the NANOGrav dataset to further constrain the equation of state. She looks forward to conducting joint analyses of radio and Gamma/X-ray data to improve NANOGrav's sensitivity and further understand the behavior of matter at supranuclear densities.
Host Institution: Institute for Advanced Study
Proposal Title: Exploring the Nature of Dark Matter Using Low Surface Brightness Galaxies
Shany Danieli grew up in Tel Aviv, Israel, and received her undergraduate degree in physics from Tel Aviv University. She moved to the US for her graduate studies and soon will complete her PhD in physics at Yale University under the supervision of Prof. Pieter van Dokkum. Shany will be taking her NHFP Hubble Fellowship to the Institute of Advanced Study in Princeton, NJ.
Shany's dissertation research focuses on studying the lowest-mass galaxies in the universe which serve as primary probes for testing cosmology on small scales and the edge of galaxy formation. She used innovative methods and instrumentation to discover faint galaxies beyond the Local Group and study their dark matter content. Among those are dwarf galaxies in the Local Volume, as well as ultra-diffuse galaxies.
As part of her work, she was a member of the core team that developed the Dragonfly Telescope. In addition to imaging with Dragonfly, much of her work included follow-up observations using the Hubble Space Telescope and the two 10-meter W. M. Keck Observatory telescopes. She designed and leads the Dragonfly Wide Field Survey, a comprehensive survey of the low surface brightness universe.
As a Hubble fellow, Shany aims to provide further observational constraints on dark matter models by studying faint galaxies on various small scales. She plans to combine high-resolution imaging and spectroscopic data along with dynamical modeling of individual galaxies, with the goal of improving our understanding of the physical processes involved in their formation and growth.
Host Institution: Northwestern University
Proposal Title: Stellar Afterlives and Black Hole Cataclysms: Learning about Stars, Galaxies, and the Cosmic Expansion with Gravitational Waves
Maya Fishbach grew up in Chicago. After graduating from Yale University in 2015 with a BS in math and physics, Maya returned to Chicago, where she is currently completing her PhD at the University of Chicago under the supervision of Daniel Holz.
Maya uses gravitational waves to probe the universe's most extreme objects—black holes and neutron stars. For her PhD, Maya analyzed LIGO-Virgo data to study the population properties of colliding black holes and to measure the expansion rate of the universe. Some of these results include: the discovery of an upper-mass gap in the black hole mass spectrum (likely due to pair-instability supernovae), evidence that the black hole merger rate evolves with redshift, and the first standard siren measurement of the Hubble constant using a gravitational-wave event and a galaxy catalog. As an Einstein fellow, Maya will continue to explore where, when, and how black holes and neutron stars are made, drawing connections between gravitational-wave data and simulations and observations of stars and galaxies.
Host Institution: University of California, Santa Cruz
Proposal Title: The Role of Aerosols in the Formation and Early Evolution of Giant Planets
Peter Gao was born in Tianjin, China and immigrated to Vancouver, Canada when he was nine years old. He obtained his Bachelor's degree in physics from the University of British Columbia and his PhD in planetary science from the California Institute of Technology. After graduating, he spent several months as a NASA Postdoctoral Program Fellow at NASA Ames Research Center before becoming a 51 Pegasi b Fellow at the University of California, Berkeley.
Peter's research focuses on understanding the physics and chemistry of planetary atmospheres within and beyond the Solar System. He is particularly interested in deciphering the multifaceted impact of aerosols on the chemistry, radiative transfer, and observations of planetary atmospheres. As a Sagan Fellow, Peter will study the atmospheres of young and accreting planets to understand the initial conditions of planetary and atmospheric evolution. Young planets have been shown to have dusty atmospheres which impede interpretations of their emission spectra. However, the origin and nature of the dust are uncertain. Peter will use a combination of theoretical models and observations from ground- and space-based telescopes to investigate the dust and emergent spectra of young planets. Not only will this work lead to better constraints on the composition and formation processes of these worlds, but it will also help connect them to the vast diversity of mature exoplanets that we have observed across the Galaxy.
Host Institution: Carnegie Observatories
Proposal Title: Finding and Characterizing the Missing Stars Stripped in Binaries—From Gravitational-wave Events to the High-redshift Universe
Ylva Gotberg received her PhD degree the 7th of February 2019 at the University of Amsterdam, The Netherlands. She grew up in Sweden and studied at Lund University to become physics engineer, but during exchange studies in Grenoble, France she became interested in astronomy.
Ylva's research focuses on interacting binary stars and their influence on their surroundings—both nearby and at high redshift. She computes binary stellar evolutionary and spectral models for products of binary interaction and uses these to understand the impact of envelope-stripped stars on the ionizing emission of galaxies and their contribution during cosmic reionization. These models can also be used to search for binary products in resolved and unresolved stellar populations; this will be her main focus as a Hubble fellow. Such observational verifications will provide important constraints on stellar evolution models and will therefore have direct impact on spectra of distant galaxies and the formation of gravitational-wave sources.
Host Institution: Carnegie Observatories
Proposal Title: Stellar Scouts: Tidal Disruption Events as Probes of Black Holes
Tom Holoien grew up in the San Francisco Bay Area and received a bachelor's degree in East Asian studies from Stanford University in 2008. He later obtained a second bachelor's degree in astrophysics from Rutgers University in 2013, followed by a PhD in astronomy from the Ohio State University in 2017. His PhD work was supported by the Department of Energy Computational Science Graduate Fellowship and his thesis was advised by Professors Krzysztof Stanek and Christopher Kochanek. After obtaining his PhD, he became a Carnegie Postdoctoral Fellow at Carnegie Observatories.
Tom's research focuses on using large-scale sky surveys to discover and study the explosive deaths of stars. He is a founding member of the All-Sky Automated Survey for Supernovae (ASAS-SN) and works primarily on supernovae and tidal disruption events (TDEs)—flares from stars falling into supermassive black holes. As an Einstein Fellow, Tom will focus his efforts on expanding observational studies of TDEs into areas that have historically been lacking: early time (shortly after disruption) and very late times (years following disruption). His goal is to provide the observational data needed to improve theoretical models of TDE emission, which will allow TDEs to be used as probes of black holes that are otherwise impossible to study.
Marc Teng Yen Hon
Host Institution: University of Hawaii
Proposal Title: Unraveling the History of the Galaxy with TESS Asteroseismology
Marc Hon grew up in Kuala Lumpur, Malaysia. He received his bachelor’s degree in physics and mathematics at the University of Wollongong, Australia with first class honors. Marc will soon earn his PhD in astrophysics at UNSW Sydney, Australia, with Dennis Stello as his advisor.
Marc's research combines two exciting research fields: the asteroseismology of Sun-like stars and artificial intelligence. For his PhD thesis, he developed data-driven techniques to systematically find and characterize stellar oscillations in red giant stars. His work has enabled the precise determination of the fundamental properties of stellar populations, including their ages, around the Milky Way using data from NASA's Kepler and K2 missions. As a Hubble Fellow at the University of Hawai'i, Marc will extend the reach of red giant asteroseismology towards the whole sky with NASA's Transiting Exoplanet Survey Satellite (TESS), where he aims to trace the chemical and dynamical history of the Milky Way by measuring precise stellar ages across a vast expanse of the Galaxy.
Host Institution: University of Michigan
Proposal Title: Mapping the Evolving Conditions of Planet Formation
Jane Huang grew up in Chicago, Illinois and received her undergraduate degree in chemistry at the University of Chicago. She will earn her PhD in astronomy and astrophysics at Harvard University, where she works with Dr. Sean Andrews and Professor Karin Öberg.
Jane's research has leveraged the unprecedented sensitivity and resolution of ALMA to map ring and spiral structures in protoplanetary disks and explore their implications for planet formation mechanisms. As a Sagan Fellow at the University of Michigan, Jane will use multiwavelength observations of disks to explore the full range of possible planet formation conditions. Through systematic studies of the structure and chemical composition of disks, she aims to contextualize the diversity of the exoplanet population.
Host Institution: University of California, Berkeley
Proposal Title: Oscillating Neutrinos in Core-collapse Supernovae
Luke Johns grew up in Maryland and received a bachelor's degree in physics from Reed College in Portland, Oregon. He is currently completing his PhD at the University of California, San Diego, advised by Prof. George Fuller. As a graduate student he has been supported by an Inamori Fellowship and a DOE SCGSR award.
Luke's research is centered on neutrinos and dark matter. He's particularly interested in the problem of neutrino oscillations in astrophysical environments. The bulk of his thesis work focused on the cosmological setting, where neutrino mixing has connections to Big Bang nucleosynthesis, the cosmic microwave background, and various theories beyond the Standard Model of particle physics. As an Einstein Fellow at the University of California, Berkeley, he'll seek to understand how neutrino flavor evolves in core-collapse supernovae and neutron-star mergers. Oscillations have potentially important effects on dynamics and nucleosynthesis, but reliable calculations have been elusive due to the nonlinear, multiscale nature of the problem. Luke will work to establish the theoretical insights and computational techniques needed to make an assessment of oscillation effects possible.
Host Institution: University of California, Santa Cruz
Proposal Title: Supernova Cosmology in the Era of Cosmological Tensions
David grew up in Corvallis, Oregon. He received bachelor's degrees in astronomy and brass performance from Boston University in 2010, and a master’s in astronomy from Boston University in 2011. David did his PhD work with Professor Adam Riess at the Johns Hopkins University, and from there became a postdoctoral fellow at the University of California, Santa Cruz.
David is working to understand the physics of the 70% of our universe comprised of dark energy—the mysterious cause of cosmic acceleration—and to measure the expansion rate of the nearby universe (the Hubble constant) using Type Ia supernovae as cosmological tools. David played a leading role in the best current measurement of dark energy properties from Type Ia supernovae and is currently Project Scientist of the Young Supernova Experiment, a new time-domain survey to understand stellar explosions and enhance the sample of nearby, well-observed supernovae.
The next decade will bring the discovery of hundreds of thousands of new Type Ia supernovae through the Vera C. Rubin Observatory and the WFIRST telescope, data that could transform our knowledge of dark energy, the Hubble constant, and gravity itself. David will spend his fellowship years leading projects to increase the fidelity of Type Ia supernovae as cosmological tools and he looks forward to using the wealth of forthcoming data to better understand the physics of our universe. In his free time, David enjoys hiking and surfing.
Host Institution: American Museum of Natural History
Proposal Title: Uncovering Planet Formation in Embedded Disks
Aleksandra Kuznetsova was born in Russia, but grew up stateside. In 2014, she graduated from the University of Rochester with undergraduate degrees in physics and astronomy, and geology. Aleksandra will complete her PhD in astronomy and astrophysics, advised by Lee Hartmann, at the University of Michigan in the spring of 2020.
Aleksandra's research focuses on understanding how conditions in the star-forming environment influence the properties of planet-forming disks. Aleksandra uses numerical simulations to follow protostellar core formation from the top-down, following the formation of clusters from molecular clouds to get at the range and distribution of disk initial conditions. Her thesis work has characterized how protostellar cores accrete mass and angular momentum, advancing our understanding of infall and its role in disk processes. As a Sagan Fellow, Aleksandra will investigate the effects of infall-induced structure formation on disk dynamics and planet formation in protostellar disks.
Host Institution: The Ohio State University
Proposal Title: Two Projects with Circumbinary Planets—Using the Planets to Solve Super-Earth Formation, and the Binaries to Empirically Constrain M-dwarfs
David grew up in Melbourne, Australia. When his cricket career was cut short, he concentrated on astrophysics at Monash University, graduating in 2012 and undertaking exoplanet research with Rosemary Mardling. In 2013 David moved to Switzerland to commence a PhD with Stéphane Udry at the Université de Genève. David spent four years playing and watching hockey, and studying planets orbiting double star systems, known as circumbinary planets. He graduated in 2017 and then moved to the University of Chicago for two years as a fellow of the Swiss National Science Foundation, working with Dan Fabrycky. David was then recruited by the Ohio State University as a Columbus Postdoctoral Fellow.
David will continue his research on planets in binaries at the Ohio State University as a Sagan Fellow. Whilst it may seem like a niche topic at first glance (and, admittedly, second and third), circumbinary planets can provide a unique perspective on how planets form in general. In particular, he wants to know if small planets, such as super-Earths, are as abundant around two stars as they are around one. This comparison would help confirm whether small planets form far from stars and then migrate inwards (possible around either one or two stars), or if they form in situ (possible around one star but unlikely around binaries). The first step, though, is to develop and implement methods to actually find small circumbinary planets, which sneakily elude standard detection techniques. Equally sneaky is David's dog Stanley, who has had his "good boy" status questioned.
Host Institution: Princeton University
Proposal Title: Formation and Dynamics of Short-period Exoplanetary Systems
Sarah Millholland grew up in Madison, Wisconsin. She attended the University of St. Thomas in St. Paul, Minnesota, where she was a Goldwater Scholar, and she obtained bachelor degrees in physics and applied mathematics in 2015. Sarah began her graduate education at the University of California, Santa Cruz. After one year, she transferred to Yale University to follow her advisor, Professor Gregory Laughlin. At Yale, Sarah was a National Science Foundation Graduate Research Fellow from 2017–2020. She will graduate with a PhD in astronomy from Yale University in May 2020.
Despite the prevalence of extrasolar worlds, zeroth-order mysteries about their nature persist, such as how they formed and what sets their physical characteristics. Gravitational dynamics are required to decipher these mysteries and nearly every aspect of planetary systems—from orbital evolution, to interiors and atmospheres, as well as primordial formation processes. Sarah's research addresses these questions using a data-driven dynamics approach at the interface between observational data and celestial mechanics theory. As a Sagan Fellow, Sarah will continue her studies of exoplanetary system architectures, which include the shapes and orientations of orbits, stellar and planetary obliquities, and intra-system size and orbital trends. Moreover, she will study the unique links that exist between these architectural characteristics and planetary physical properties.
Host Institution: New York University
Proposal Title: Decoding Extragalactic Stellar Streams: What Will They Teach Us about Dark Matter?
Sarah Pearson grew up in Denmark and received her bachelor’s degree in physics from the University of Copenhagen in 2012. During her undergraduate studies, Sarah conducted research at UC Santa Cruz and MIT, and she subsequently continued her studies at Columbia University. Sarah received her master’s and PhD in astronomy in 2015 and 2018, and she has since held a Flatiron Fellowship at the Center for Computational Astrophysics. In addition to her research, Sarah runs the outreach program “Space with Sarah.”
Sarah’s work focuses on galactic dynamics, inducing the growth of the universe’s smallest galaxies, as well as stellar streams from globular clusters in our own and nearby galaxies. Most notably, Sarah has shown how stellar streams are affected by the spinning Galactic bar in our Galaxy. When dark matter subhalos have close encounters with stellar streams, similar signatures are expected, and her work therefore provides important clues for how to best search for dark matter in our Galaxy. As a Hubble Fellow, Sarah will decode what current and future surveys of extragalactic stellar streams will teach us about dark matter.
Host Institution: Space Telescope Science Institute
Proposal Title: Integrated Coronagraphy and Wavefront Sensing for Future Giant Segmented Space Telescopes
Emiel Por grew up in the city of Zoetermeer in the Netherlands. He received a double bachelor's degree in physics and astronomy and a master's degree in astronomical instrumentation from Leiden University in 2013 and 2016 respectively. He continued at Leiden University and will receive his PhD in astronomy in the summer of 2020.
Emiel's research focuses on advanced instrumentation for the direct imaging of exoplanets for both ground- and space-based telescopes. He develops novel coronagraph solutions, such as the single-mode complex amplitude refinement and phase-apodized-pupil Lyot coronagraphs, and methods for post-coronagraphic wavefront sensing. Segmented primary mirrors, such as the one proposed for LUVOIR, require that all segments stay aligned to within a few picometers during a coronagraphic observation. Therefore, besides a high-performance coronagraph, high-order wavefront sensing and control will be necessary for future giant segmented space telescopes. As an NHFP Sagan fellow at the Space Telescope Science Institute, Emiel will work on developing coronagraph solutions that jointly optimize both contrast and wavefront sensing and control capabilities.
Host Institution: California Institute of Technology
Proposal Title: Of Worlds to Come: Delivering on the Promise of Extreme Precision Spectroscopy for Exoplanets
Arpita Roy grew up in Calcutta, India, and received a bachelor's degree in astrophysics and English (creative writing) from Franklin & Marshall College in 2009. She then went on to earn her PhD in astronomy and astrophysics from the Pennsylvania State University in 2017, under the supervision of Dr. Suvrath Mahadevan. Arpita has been a Millikan Prize Postdoctoral Fellow at the California Institute of Technology since then, working with Dr. Andrew Howard and the California Planet Search team.
Arpita's research focuses on improving instrumentation and data analysis techniques for the detection of exoplanets, in order to advance into the realm of extreme precision spectroscopy necessary for the discovery of Earth analogs. She is part of six next-generation instrument teams, spanning both the optical and near infrared, including serving as Project Scientist for the upcoming Keck Planet Finder spectrograph. Combining hardware innovation along with tailored software development and careful consideration of stellar false positives, Arpita aims to ultimately use these high-fidelity instruments for the direct detection of reflected planetary light, which would open up a new regime of exoplanet characterization.
Host Institution: University of California, Davis
Proposal Title: Accurate Galaxy Metallicities and a Robust Interpretation of Emission Lines at High Redshifts: Crucial Preparatory Work for JWST
Ryan Sanders was born in Texas, and grew up in Atlanta, Georgia and Chicago, Illinois. In 2012, he graduated summa cum laude from the University of Louisville with a bachelor of science in physics and a bachelor of music in jazz performance. He received his PhD in astronomy from UCLA in 2018 under the supervision of Alice Shapley, and has been working as a postdoc at UC Davis with Tucker Jones since then.
Ryan is interested in understanding the formation and evolution of galaxies through observations, primarily via spectroscopy. Galaxies grow through a cycle involving the accretion of gas from the intergalactic and circumgalactic medium, star formation, and feedback processes that drive gas outflows. The abundance of metals (elements heavier than helium) in the interstellar medium is a sensitive probe of this cycle of baryons, and measurements of metallicities across a wide range of galaxy properties and redshifts can reveal how galaxies grow throughout cosmic history. Measuring metallicities in the high-redshift universe is particularly difficult and currently suffers from systematic uncertainties related to the evolution of the properties of gas and stars in star-forming regions. As a Hubble Fellow, Ryan will use deep spectroscopy of high-redshift galaxies to improve methods of measuring metallicity in the early universe, and apply these methods to existing galaxy surveys and the first wave of spectra from the James Webb Space Telescope to characterize the build-up of heavy elements from the epoch of reionization to the present day and understand how galaxies grow at different epochs.
Host Institution: Massachusetts Institute of Technology
Proposal Title: Dark Sectors in High-redshift Observations
Katelin Schutz grew up in the Finger Lakes region of upstate New York. After completing her bachelor's degree in physics at MIT, Katelin moved to UC Berkeley in 2014 for her PhD with the support of the Hertz Foundation and the National Science Foundation. Her thesis, titled "Searching for the Invisible: How Dark Forces Shape our Universe" was supervised by Hitoshi Murayama and won the American Physical Society Sakurai dissertation award in theoretical particle physics. In 2019, Katelin moved to the MIT Center for Theoretical Physics as a Pappalardo Fellow.
Katelin Schutz works at the interface of theoretical particle physics, astrophysics, and cosmology. Her aim is to recover every bit of information about what our Universe is made of by considering how astrophysical systems would be affected with the addition of new particles and interactions. While primarily a theorist, Schutz sometimes gets her hands dirty with data. In the course of thinking about astrophysical signs of new physics, she has harnessed the constraining power of systems ranging from millisecond pulsars to dwarf galaxies to the cosmic microwave background. The search for new particles and interactions is at somewhat of a crossroads: while we know that the Standard Model of particle physics is incomplete, there have been few hints of what nature has in store. With that in mind, Schutz plans to continue with a multipronged strategy on the astrophysics front, helping to ensure that no stone goes unturned.
Host Institution: University of Washington
Proposal Title: From Astronomy to Chemistry: Towards a Continuous Path for the Origins of Life
Zoe Todd is from central Pennsylvania and received her undergraduate degrees in astrophysics, biochemistry, and physics from Penn State University. She will finish her PhD in spring 2020 at Harvard University. At Harvard, she works with Profs. Dimitar Sasselov, Karin Oberg, and Jack Szostak.
Zoe's research focuses on determining environments and circumstances favorable for the origins of life on Earth. In particular, Zoe studies which planetary environments could provide the necessary chemical feedstocks for the synthesis of the building blocks of life. Much of her work has focused on the role of UV light as a source of energy to drive prebiotic chemistry. As a Sagan Fellow, Zoe will investigate the astronomical and planetary circumstances that could lead to origins of life. Specifically, she will investigate how impacts could influence the origins of life and how the transition from building blocks of life to more complex protocellular systems could occur in the context of the planetary environment.
Host Institution: University of Arizona
Proposal Title: A New Era of Exoplanet Imaging: Mid-Infrared Exploration of the Habitable Zones of Nearby Stars
Kevin Wagner grew up in Northern Kentucky and obtained his PhD from the University of Arizona in 2020. Kevin's research is focused on exoplanets, planet formation, and exoplanet imaging instrumentation. His recent focus has been on using the rapidly maturing techniques of exoplanet imaging to study the processes of planet formation around nearby young stars. As a NASA Sagan Fellow, Kevin is focused on pushing the capabilities of exoplanet imaging toward finding and characterizing Earth-sized exoplanets in the habitable zones of nearby stars.
Host Institution: Institute for Advanced Study
Proposal Title: Cosmic Ray Diffusion in the Multi-phase Interstellar Medium
Siyao Xu was born in Yichun, China. She earned her PhD in astrophysics from Peking University in 2017. Her thesis work under the supervision of Prof. Bing Zhang on magnetohydrodynamic (MHD) turbulence and its astrophysical applications was recognized by the IAU PhD Prize and the Cecilia Payne-Gaposchkin Doctoral Dissertation Award in Astrophysics. She was a Hubble fellow at University of Wisconsin-Madison from 2017 to 2020 working on MHD turbulence and turbulent dynamo in weakly ionized astrophysical media and the applications to star formation. Her other work on cosmic ray physics and high-energy astrophysics was recognized by the IUPAP Young Scientist Prize in Astroparticle Physics in 2019.
As an NHFP Hubble Fellow at the Institute for Advanced Study, she will use the modern understanding of MHD turbulence to construct a realistic model for cosmic ray diffusion in the multi-phase interstellar medium with varying ionization degrees and magnetizations. The intended research will contribute to the ongoing paradigm shift of cosmic ray studies, as well as benefit other studies on Galactic magnetic fields and the foreground of the Cosmic Microwave Background.
Host Institution: University of Chicago
Proposal Title: Deciphering the Biography of Massive Stars: Compact Object Mergers as a Rosetta Stone
Michael Zevin grew up in the suburbs of Chicago, Illinois. He received his bachelors of science with majors in astronomy and physics, and a minor in music performance at the University of Illinois, Urbana-Champaign. Following his undergraduate studies, he spent two years working in science education at the Adler Planetarium while pursuing music with his band. He will receive his PhD in physics and astronomy from Northwestern University in the spring of 2020, advised by Professor Vicky Kalogera.
Compact binary mergers encode unique information about their progenitor systems, such as the types of galactic environments they were born in, the intricacies of stellar evolution that persisted throughout their lives, and the physics of the supernovae that marked their deaths. Michael's research focuses on leveraging the growing catalog of gravitational waves to better understand these aspects of massive-star evolution. He is also interested in how the galactic demographics of gamma-ray bursts and environments exhibiting r-process enrichment can be used to inform compact object formation and supernova mechanisms. Michael has held an active role in the LIGO Scientific Collaboration since 2015 and was one of the lead developers of the Gravity Spy project, which combines citizen science and machine learning to characterize troublesome noise in the LIGO detectors.
As a NHFP Hubble Fellow, Michael will use detailed population modeling to explore the wide range of formation channels that have been proposed for binary black hole formation, and constrain the relative rates of these channels using the hundreds of gravitational-wave observations anticipated over the next few years. He will also investigate the galactic demographics and kinematic evolution of neutron star mergers observed via electromagnetic and/or gravitational radiation to better constrain aspects of their prior stellar evolution.
➤ Last updated: March 25, 2020