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Stacey Alberts

Senior Research Associate
Ph.D., 2014, University of Massachusetts, Amherst
Areas of Interest: Galaxy Formation and Evolution, Galaxy Clusters, Star Formation, Active Galactic Nuclei, High Redshift Galaxies

Stacey's research focuses on galaxy evolution in the context of local environment through studies of massive galaxy clusters out to high redshift. Through multi-wavelength observations focusing on the mid-infrared to submillimeter, she characterizes star formation and AGN in cluster and field galaxies up to z~2 in order to determine how environment shapes galaxy properties and results in the quenched nature of cluster galaxies today. At Arizona, she has joined the Mid-Infrared Instrument (MIRI) team and is involved in planning early observations in preparation for the launch of the James Webb Space Telescope.

Jennifer Andrews

Senior Research Associate
Ph.D., 2011, Louisiana State University
Areas of Interest: Core-Collapse SNe, Evolved Massive Stars, Stellar Clusters, Initial Mass Function

Jennifer is involved in mapping the late-time evolution of massive stars using multi-wavelength observations of their interaction with their surrounding environment. This includes optical and IR light echoes and spectral changes due to circumstellar interaction. She is also interested in how, when, and where dust is formed in CCSNe, particularly with regards to mass loss from the progenitor star.

Narsireddy Anugu

Steward Observatory Prize Fellow in Astronomical Instrumentation and Technology
Ph.D., 2017, University of Porto, Portugal Areas of Interest: Protoplanetary Disks, Extrasolar planets, Interferometry, Adaptive optics, high contrast imaging

Narsireddy Anugu joined Steward Observatory in August 2019. Currently, he is a postdoctoral fellow at the University of Michigan and University of Exeter, UK. His main research focuses on optical/near-infrared high-angular resolution instrumentation. He worked on the development of ESO GRAVITY and CHARA MIRC-X interferometric instruments. Currently, he is working on CHARA adaptive optics and MYSTIC instrument developments. He has been involved and interested in imaging disks around protoplanetary and post-AGB binary objects.

Carlos Eduardo Barbosa

Research Associate
Ph.D., 2016, University of São Paulo
Areas of Interest: Galaxy Formation and Evolution, Galaxy Dynamics, stellar populations

Carlos is a visiting scientist at Steward Observatory working with Prof. Dennis Zaritsky. His research focuses on the determination of spatially resolved stellar population properties of nearby galaxies using integral field spectroscopy, and its consequences to galaxy assembly in different environments. He is also interested in methods to improve the determination of stellar populations using Bayesian statistical models joining spectroscopic and photometric observations. In this visiting program, he is involved in the study of the initial mass function of nearby galaxies observed with the WIFIS near-infrared spectrograph.

Pierre Christian

SO Prize Fellow in Theoretical and Computational Astrophysics
Ph.D., 2018, Harvard University
Areas of Interest: Black hole astrophysics and gravitational waves

Pierre is interested in studying the interaction of black holes with its environments, and how such interactions could be used to probe the physics of extreme spacetimes. He is also interested in studying the population and formation of gravitational wave sources, e.g. his latest paper studied how gravitational wave observations can be leveraged to constrain the modification of the black hole mass function due to merging black holes in star clusters. Pierre joined Steward Observatory in the fall 2018 semester.

Haeun Chung

Research Associate
Ph.D., 2019, Seoul National University Areas of Interest: Astronomical instrumentation and observational astronomy including Integral Field Spectograph, System Engineering, Galaxy Kinematics and Dynamics, Environmental Effects on Galaxy Properties, Optical Design, Software Development, Galaxy Formation and Evolution, Galaxy Interactions and Mergers

Haeun Chung joined Steward Observatory in the 2019 fall semester to work with Prof. Erika Hamden. Haeun’s research focus is on astronomical instrumentation and observational astronomy in the areas of optical spectrograph and kinematics/dynamics of galaxies. During his Ph.D., he worked on building an optical multi-IFU spectrograph (DOTIFS) from overall conceptual design to the spectrograph optical design and the software development. He is also studying environmental effects on galaxy kinematics using SDSS MaNGA data and developing an IFU data post-processing technique (deconvolution).

Taran Esplin

Peter A. Strittmatter Fellow in Astronomy & Astrophysics
Ph.D., 2017, Pennsylvania State University
Areas of Interest: Nearby Star-forming Regions, Brown Dwarfs, Circumstellar disks, Initial Mass Function, Brown Dwarf Atmospheres

Taran's research has included: searching for the classifying circumstellar disks in nearby star-forming regions, characterizing the photometric variability of the coldest known brown dwarf, measuring a new distortion correction for the Infrared Array Camera on the Spitzer Space Telescope, and determining precise parallaxes for ultra-cool brown dwarfs. He completed his Ph.D. in 2017 advised by Kevin Luhman at Pennsylvania State University. Currently Taran is searching for the least-massive members in nearby star-forming regions as the inaugural Strittmatter Fellow.

Xiao Fang

Research Associate
Ph.D., 2018, Ohio State University
Areas of Interest: Survey Cosmology, Large-Scale Structure, Compact Objects, Hierarchical Systems, stellar dynamics, Type Ia Supernovae

Xiao joined Steward Observatory on September 1, 2018 to work with Prof. Tim Eifler. As a Ph.D. student at Ohio State University, he worked on a broad range of topics, from observational cosmology to compact objects and stellar dynamics. He was also involved in analysis for the upcoming WFIRST mission.

Megan Gralla

Senior Research Associate
Ph.D., 2011, University of Chicago
Areas of Interest: Galaxy Clusters, Active Galactic Nuclei, Dusty star-forming galaxies

Megan studies galaxy clusters and groups, active galactic nuclei, and the relationship between galaxies and their environments. She works with surveys and data sets spanning the radio, millimeter-wavelength, optical and X-ray regimes. Before joining Steward Observatory, Megan worked at Johns Hopkins University and the Smithsonian Astrophysical Observatory.

Kate Grier

Research Associate
Ph.D. , 2013, Ohio State University
Areas of Interest: Active Galactic Nuclei, variability, supermassive black holes, galaxy--black hole coevolution

Kate studies variability in active galactic nuclei to learn about the physics of the inner regions around supermassive black holes and measure black hole masses. Using variability of the broad emission lines observed in AGN, Kate uses a technique called reverberation mapping to measure the distance of emitting gas from the central supermassive black holes. In addition, she uses variability in broad absorption features to learn about outflows launched from the AGN accretion disks. At Arizona, Kate has joined the NIRCam team and is working on observing preparations for the NIRCam extragalactic GTO program.

Sebastiaan Haffert

NHFP Sagan Fellow
Ph.D., 2019, Leiden University
Areas of Interest: Circum-stellar disks, Planet Formation, Exoplanet Detection and Characterization, Exoplanet Atmospheres, High-Contrast Imaging, high-spatial and spectral instrumentation, remote sensing

Sebastiaan joined Steward Observatory in October 2019 as an NHFP Sagan Fellow to work together with Dr. Jared Males and the MagAO-X team. Sebastiaan’s research focuses on the development of high spatial and spectral resolution instrumentation for the detection of exoplanets and characterization their atmospheres. During his PhD he developed the Leiden Exoplanet Instrument (LEXI), which was a pathfinder instrument for optical/NIR high-resolution integral-field spectroscopy. One of his interests is the use of optical integral-field spectroscopy for the characterization of proto-planets and their formation. He is also interested in the applying the instruments and techniques developed for astronomy in other fields.

Kevin Hainline

Senior Research Associate
Ph.D., 2012, UCLA
Areas of Interest: Active Galactic Nuclei, Obscured Quasars in the Context of Galaxy Evolution, high-redshift galaxies

Kevin looks at the relationship between active galactic nuclei and star-forming galaxies, exploring how an active central super-massive black hole grows alongside its host galaxy. His research aims to understand the extent to which obscured AGNs can affect gas throughout their hosts.

Hung-Jin Huang

Research Associate
Ph.D., 2019, Carnegie Mellon University Areas of Interest: Weak gravitational lensing, Cosmic structure formation

Hung-Jin joined Steward Observatory in September 2019 to work with Profs. Tim Eifler, Elisabeth Krause, and Eduardo Rozo. She investigates the growth of structure in our Universe to understand both cosmology and galaxy formation physics. During her Ph.D. at Carnegie Mellon University, she studied astrophysical systematics on weak lensing, with focuses on intrinsic alignment of galaxies and modeling uncertainties of baryonic physics.

Jacob Jencson

Research Associate
Ph.D., Astrophysics, 2019, Caltech
Areas of Interest: Observational astrophysics, with an emphasis ontime-domain surveys, obscured supernovae, and infrared transients.

Jacob joined Steward Observatory in the fall of 2019 to work with Prof. David Sand. For the last four years, he has helped lead the Spitzer InfraRed Intensive Transients Survey, or SPIRITS, a search for transients with Spitzer/IRAC in nearby galaxies within about 20 Mpc from Earth. His primary research interests are uncovering hidden, heavily obscured supernovae and other kinds of dusty eruptions and explosions of massive stars.

Shuo Kong

Research Associate
Ph.D., 2016, University of Florida
Areas of Interest: Galactic Star Formation, Molecular Clouds, Jets and Outflows, Radio Interferometry, Astrochemistry

Shuo is interested in understanding all aspects of the star formation process, including the initial conditions, the protostellar accretion, and feedback. His research focuses on the physical and chemical properties of giant molecular clouds (including infrared dark clouds), the interplay between filaments, magnetic fields, and protostellar accretion, and the radiative and mechanical feedback effects from young massive stars. Shuo mainly uses mm radio single-dish and interferometric telescopes (e.g., SMT, ALMA) for his research. He is leading the data reduction and reporting of two CARMA large programs that produce degree-size maps of the Orion A Cloud and the North American Nebula. Recently, he is interested in how Galactic-scale structures regulate star formation.

Leonardo Krapp

Research Associate
Ph.D., Astrophysics, 2019, University of Copenhagen Denmark
Areas of Interest: Plasma physics in the framework of non-ideal Magnetohydrodynamics and multi-species dynamics

Leonardo is currently a PhD student working in the Theoretical Astrophysics Group, at the Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen, Denmark. He joined Steward Observatory in fall 2019 as a Postdoctoral Research Associate to work with Professors Kaitlin Kratter and Andrew Youdin. Leonardo obtained his degree in Astronomy in 2015 at Universidad Nacional de Córdoba, Córdoba, Argentina. His research is focused on numerical Astrophysics applied to planet formation and protoplanetary disk dynamics. His interests include plasma physics in the framework of non-ideal Magnetohydrodynamics and multi-species dynamics accounting for the momentum transfer between multiple species, in particular, the aerodynamics coupling between gaseous fluids and dust grains.

Sebastiaan Krijt

NASA Hubble Fellow
Ph.D., 2015, Leiden University, The Netherlands
Areas of Interest: Protoplanetary Disks, dust coagulation, Planet Formation

Sebastiaan joined Steward Observatory on September 1, 2018 to work with Prof. Daniel Apai. Sebastiaan uses numerical simulations to study the behavior of dust particles in protoplanetary disks. He is interested in understanding how, where, and when microscopic dust grains coagulate to form km-size planetesimals (the building blocks of planets), and how the dynamical behavior of dust grains influences the chemical composition of the growing solids and the protoplanetary nebula as a whole.

Gwang-Ho Lee

KASI-Arizona Postdoctoral Fellow
Ph.D. in Astronomy, 2017, Seoul National University, Korea
Areas of Interest: Galaxy Formation and Evolution, Environmental Effects on Galaxy Evolution, Galaxy Clusters/ Groups, Post-Starburst Galaxies, Stellar & ISM Properties in Galaxies

Dr. Lee joined Steward Observatory in September 2017. Gwang-Ho Lee's research mainly focuses on studying which mechanisms trigger galaxy transition from star-forming galaxies into quiescent galaxies, and what happens during the galaxy transition. During his Ph. D. course, he studied the multi-wavelength properties of galaxies in a full range of environments to understand the environmental effects on galaxy evolution. He is involved in several post-starburst galaxy projects using the Gemini telescope.

Jarron Leisenring

Senior Research Associate
Ph.D., 2011, University of Virginia
Areas of Interest: Protoplanetary Disks, Extrasolar planets, high contrast imaging, IR Instrumentation

Jarron's research focuses on the evolution of protoplanetary disks and how it relates to planet formation. In support of these research goals, Jarron contributes towards the development of IR instrumentation projects such as LBTI/LMIRcam and has most recently joined the JWST NIRCam team as an instrument test scientist.

David Lesser

Research Associate
Ph.D., 2019, University of Arizona

David received his my bachelor's degree in physics from Oberlin college and his PhD in Astronomy and Astrophysics from the University of Arizona. His research focuses on studying the lifecycle of the interstellar medium, and building terahertz instrumentation to do so. He also works on improving undergraduate and K-12 STEM education through exposing students to practical design experiences.

Michael Lundquist

Research Associate
Ph.D., Physics, 2015, University of Wyoming
Areas of Interest: Star Formation, Stellar Clusters, Massive Stars, time domain astronomy, Instrumentation

Michael Lundquist joined Steward Observatory on August 1, 2018. Michael is an observational astronomer with broad research interests. His research background includes studies of classical novae, massive stellar binaries, and intermediate-mass star-forming regions. Michael works with Prof. David Sand as part of the DLT40 supernova survey.

Garreth Martin

KASI-Arizona Joint Postdoctoral Fellow for Advanced Study in Astronomy & Astrophysics
Ph.D., Astrophysics, 2019, University of Hertfordshire
Areas of Interest: cosmological simulations, data-mining / unsupervised machine-learning techniques, low-surface-brightness galaxies, Galaxy Formation and Evolution, galaxy-black-hole co-evolution, galaxy mergers and galaxy morphology

Garreth joined Steward Observatory in the fall of 2019. His research lies at the interface between observational and theoretical astronomy, combining state-of-the-art hydrodynamical simulations, survey data and machine-learning techniques. He is interested in how the diversity of present-day galaxy populations arises during their assembly and how underlying processes like mergers, feedback and environmental processes drive these changes. His current work focusses on the formation mechanisms, evolution and morphology of low-surface-brightness galaxy populations that have gone almost unnoticed in previous wide-area surveys and represent an important additional axis for constraining our understanding of galaxy evolution.

Vivian Miranda

Research Associate
Ph.D., 2015, University of Chicago
Areas of Interest: Dark Energy, Inflation, Cosmic Microwave Background, Weak Lensing, Cluster Cosmology

Vivian Miranda joined Steward Observatory on September 1, 2018, to work with Prof. Elisabeth Krause. Vivian's research is focused on probing inflation, the epoch of reionization and dark energy with the Cosmic Microwave Background. She has done her Ph.D. at the University of Chicago under the guidance of Prof. Wayne Hu. Vivian is also keen on understanding how extensions of the LCDM model can be constrained via the combination of the CMB with low redshift probes. As a postdoc at the University of Pennsylvania, she has developed research on how to test fundamental assumptions about the standard model using model-independent techniques. At the University of Arizona, Vivian intends to dedicate her time to the Dark Energy Survey (DES), in particular, to cluster cosmology and weak lensing. Vivian's work stands on the bridge between theory and data, and she is open to radically new ideas, as long as it can be falsified by either the CMB or the DES/LSST/WFIRST surveys. In 2019, Vivian was awarded the Leona Woods Distinguished Postdoctoral Lectureship Award.

Maxwell Moe

NASA Einstein Fellow
Ph.D., 2015, Harvard University
Areas of Interest: Binary Star Formation and Evolution, Eclipsing Binaries, Type Ia Supernovae

Max utilizes large datasets of eclipsing binaries (EBs) to understand the formation, environments, and evolution of massive stars and binaries. In particular, Max measures the statistical distributions of binary star properties to test binary formation models and to provide initial conditions for binary population synthesis studies. He also incorporates EB populations to investigate tidal evolution, binary mass transfer and accretion processes, pre-main-sequence evolution, triple stars, feedback and dust content in young stellar nurseries, and the progenitors of Type Ia supernovae and X-ray binaries.

Burçin Mutlu-Pakdil

Research Associate
Ph.D. , 2017, University of Minnesota, Twin Cities Areas of Interest: Structure, Morphology, and Dynamics of Galaxies; Galaxy Evolution; Black Hole-Galaxy Co-evolution

Burcin's research interests encompass both theoretical and observational aspects of extragalactic astronomy. She studies the structure and dynamics of galaxies, and examines what these can tell us about the galaxy formation process. Her recent research in galaxy structure has led to a discovery of an extremely rare galaxy. This work has provided a first description of a double ringed elliptical galaxy. Currently, she works on the general topics of nearby galaxies, resolved stellar populations and near-field cosmology.

Karen Olsen

Research Associate
Ph.D., Astronomy, 2015, Copenhagen University
Areas of Interest: Galaxy Formation and Evolution, ISM Emission Modeling, cosmological simulations, ISM Properties of Galaxies, Far-infrared Line Emission, Intensity Mapping in the Far-infrared

Dr. Karen Olsen works to better understand galaxy evolution by studying the properties of the interstellar matter (ISM). Her overarching goal is to bridge the gap between spectroscopic observations of the ISM and numerical models of galaxy formation. In that quest, Karen has built a unique and world-leading tool called SIGAME to model line emission from the ISM in the far-infrared (FIR) utilizing state-of-the-art cosmological galaxy simulations. By comparing the output of this modeling to observations with large interferometers such as ALMA, VLA and NOEMA, SIGAME helps to unveil the physics of the ISM - the driving component in galaxy evolution. Before coming to Steward Observatory, Karen received her PhD from the Dark Cosmology Centre at the Niels Bohr Institute in Denmark, and enjoyed a three-year postdoctoral fellowship at Arizona State University.

Cristobal Petrovich

Bart J. Bok Fellow for Advanced Study in Astronomy and Astrophysics
Ph.D., 2015, Princeton University Areas of Interest: Orbital dynamics, Exoplanets, Compact Objects, Gravitational wave source and Disk-planet interactions

Cristobal joined Steward Observatory in August 2019. His research focuses on understanding the formation and evolution of planetary and stellar systems using the information encoded in their orbits and astrophysical environments. He did his PhD at Princeton where he studied the role of orbital migration at shaping the architecture of observed exoplanet systems. Currently, as a postdoc at CITA, he has also worked on the dynamics of multi-stellar systems and their role at producing gravitational wave sources.

Everett Schlawin

Senior Research Associate
Ph.D., 2015, Cornell University Areas of Interest: Exoplanets, Atmospheres, Instrumentation

Everett is interested in what planets and their atmospheres are made of. He studies planet composition by observing transiting planets - planets that cross in front and behind their host stars. Everett is a member of the James Webb Space Telescope NIRCam team, led by Marcia Rieke. The unprecedented Webb telescope will enable giant leaps in our understanding of planet composition. Personal Website:

Irene Shivaei

NASA Hubble Fellow
Ph.D., 2017, UC Riverside

Irene Shivaei earned her Ph.D. at UC Riverside, advised by Professor Naveen Reddy. Her work is part of the MOSDEF project to use the multi-object near-infrared spectrograph MOSFIRE on the Keck I Telescope to study the high redshift (z~2) Universe. She has focused on determining accurate star formation rates, comparing estimates from H alpha and H beta with those from infrared measurements, and on the behavior of the mid-infrared aromatic bands with metallicity. She will expand this work with JWST, using MIRI GTO data in the Hubble Ultra-Deep Field region. Irene is also involved in outreach, for example as a co-founder of the StarYab astrophysical literature website with weekly discussions of recent astronomy research results in Persian.

Jordan Stone

NASA Hubble Fellow
Ph.D., 2015, University of Arizona Areas of Interest: Star and Planet Formation, Brown Dwarf and Exoplanetary Atmospheres, High-Contrast Imaging, Interferometry

I've been working to understand the physical nature of protoplanetary disks around young stars to better understand how the late evolution of proto-star--disk--proto-planet systems produce the variety of planetary systems observed.

Carlos J. Vargas

Research Associate
Ph.D., 2018, New Mexico State University
Areas of Interest: Galaxy Evolution, Star Formation, ISM/CGM, Disk-halo interface, Radio/sub-mm Astronomy

Carlos studies the relationship between star formation and the diffuse inner halos of spiral galaxies. He is particularly interested in the mechanisms behind the prevalence and support of matter residing outside of star-forming galaxy disks. He has led studies analyzing the cycling of gas and cosmic rays between galaxy disks and halos, as well as a study of high redshift Lyman-alpha emission. Carlos joined Steward Observatory in September of 2018 to work with Dr. Erika Hamden.

Feige Wang

NHFP Hubble Fellow
Ph.D., 2017, Peking University
Areas of Interest: High Redshift Quasars, cosmic reionization, Black Hole Growth, Galaxy Formation and Evolution

Feige Wang joined Steward Observatory as an NHFP Hubble Fellow in the fall of 2019, and will be working with Prof. Xiaohui Fan. His research focuses on finding the most distant super-massive black holes (SMBHs) and using the most distant quasars to investigate when did reionization occur, what was the SMBH accretion history and how was the growth of the SMBHs linked to the assembly of early massive galaxies. He obtained his Ph.D. from the Peking University in 2017. Afterwards, he moved to the University of California, Santa Barbara as a post-doc for two years.

Sixiang Wen

Research Associate
Ph.D., 2018, Sun Yat-sen University
Areas of Interest: Tidal Disruption Events, Dark Energy

Sixiang Wen joined Steward Observatory in January 2019 working with Prof. Ann Zabludoff. His research focuses on modeling the accretion of Tidal Disruption Events from first principles. Sixiang is currently working on fitting the X-ray spectrum and light curve of TDEs to constrain the mass and spin of the central supermassive black hole. His other interests include dark energy and black hole astrophysics.

Ryan Westernacher-Schneider

Research Associate
Ph.D., Physics, 2018, University of Guelph
Areas of Interest: Turbulence, core-collapse supernovae, Relativistic Astrophysics, Gravitational Waves, Numerical Relativity, Fluid-Gravity Duality

Ryan Westernacher-Schneider joined Steward Observatory on September 1, 2018 to work with Prof. Vasilis Paschalidis. Ryan grew up in Toronto, Canada. He was an undergraduate at the University of Toronto, and did his graduate studies at the University of Guelph and the Perimeter Institute for Theoretical Physics with Luis Lehner. He has worked on the statistical theory of relativistic turbulence using analytic techniques and numerical simulations, and applied it to turbulent black holes via the fluid-gravity duality. He has ongoing work on tidal disruption events, as well as gravitational wave asteroseismology of core-collapse supernovae and associated multimessenger detection strategies.

Christina Williams

NSF Fellow
Ph.D., Astronomy, 2014, University of Massachusetts Amherst Areas of Interest: Galaxy Formation and Evolution, Stellar Feedback, galactic outflows

Jinyi Yang

Research Associate
Ph.D., 2017, Peking University
Areas of Interest: High-z Universe & Reionzation, High-z Quasar/AGN evolution, Super massive black hole growth, Quasar surveys at multi-redshift ranges, and Absorption Systems in quasar spectra

Dr. Yang joined Steward Observatory in November 2017. Jinyi's research focuses on quasar evolution and quasar surveys at high redshift. During her thesis, she measured the quasar luminosity function at z ~ 5 and studied the quasar evolution model at high redshift. She carried out a survey of quasars at the redshift gap (z~5.5) of quasar color selection using a new selection pipeline. She is working on the study of multi-wavelength properties of quasars and the co-evolution between SMBHs and quasar host galaxies at z>~5, and is also involved in searching and follow-up works of quasars at z>~6. Additionally, she is interested in absorption systems towards quasar spectra, which can trace the redshift evolution of neutral hydrogen and metals in the intergalactic and galactic scales. At Steward Observatory, she will continue the research on high redshift quasars and the cosmic reionization.

Huanian Zhang

Research Associate
Ph.D., 2016, University of Arizona
Areas of Interest: Galaxy structure and gas halos, low surface brightness galaxies.

Huanian received his Ph.D in theoretical particle physics, specifically in new physics beyond Standard Model. Huanian's research mainly focuses on ionized gas halos of low redshift galaxies. Using a sample of nearly half a million foreground galaxies, probed by over 7.4 million low-background spectra from the Sloan Digital Sky Survey Data Release 12, Huanian traces Halpha emission to about 100 kpc galactocentric radius. Huanian has also presented the first evidence for a widely distributed, neutral, excited hydrogen component of the Milky Way Galaxy that is observed only as slight absorption in the combined spectra of millions of galaxy spectra. Huanian's research interests also include mapping the CGM of individual galaxies, searching for globular clusters within the local volume, and building the all-sky catalog of Ultra Diffuse Galaxies.