Alumni

Former members of the EPSIG team, now on to new adventures elsewhere...

Alumni - Students

Schuyler Wolff (Ph.D. '17):  Now an Oort Postdoctoral Fellow at Leiden Observatory. I am a graduate student at Johns Hopkins University and a member of the Gemini Planet Imager Team. I am interested in studying the processes of planetary system formation by in-depth characterization of circumstellar systems observed at various evolutionary stages using the Gemini Planet Imager and the Hubble Space Telescope. 

Sylvain Egron: I'm a Ph.D. student working on the James Webb Space Telescope Optical Simulation Testbed. My research is about the WFS&C of JWST, implementing algorithms to align the secondary mirror and the segments of the primary mirror of JWST. My team also includes people from the Laboratoire d'Astrophysique de Marseille and from ONERA in Paris.

 Alex Greenbaum (Ph.D. '16):  Now a postdoc at University of Michigan.  As a graduate student at Johns Hopkins University, I worked on a high angular resolution technique called non-redundant masking (NRM) that can be used for the direct detection of young planets in the process of formation. I work with the non-redundant mask on the Gemini Planet Imager to look for these young planets and learn about how the instrument performs. I use the same concepts to do simulations for the NRM on the James Webb Space Telescope. I am also interested in wavefront sensing and image reconstruction.

Bin Ren: I am a graduate student working on the modeling of the circumstellar disks discovered in the NICMOS and STIS archives of the Hubble Space Telescope. Before this, I did two things using the Karhunen-Loeve Image Projection algorithm: 1) built a pipeline that finds the centers and reduces all the STIS data to find circumstellar disks, and 2) processed the STIS Program 14426 data, empowering STIS with the dithering strategy for the new BAR5 occulter, and calculated its contrast curve.

Olivier Levecq

Elena Gofas Salas

Alumni - Postdocs 

Mamadou N'Diaye: My research interests deal with exoplanet direct imaging and spectroscopy. I have been doing research and development in astronomical instrumentation, investigating innovative concepts in coronagraphy and wavefront sensing.

Jackie Radigan: Now a Faculty Member at Utah Valley University. I am interested in understanding and characterizing cloudy brown dwarf and giant planet atmospheres using photometric and spectroscopic techniques, with a focus on NIR variability.  My favorite objects to study are L/T transition brown dwarfs, which can be highly variable due the presence of patchy clouds and weather patterns in their photospheres.

Marie Ygouf: Now a postdoc at IPAC/Caltech.  My current research focuses on high-contrast multispectral imaging in view of directly detecting and characterizing exoplanets. In this framework, the development of innovative image post-processing methods is essential in order to eliminate the quasi-static speckles in the final image, which remain the main limitation for high contrast. More generally, I am interested in improving the performance of future instruments for high-contrast imaging, taking profit from data analysis, and the detailed characterization of the instrumental limitations and calibration capabilities. My fields of interest include direct detection of exoplanets, image processing, high angular resolution and high contrast techniques, wavefront sensing and control, simulation, modeling, and optical design.

Elodie Choquet - now a Hubble Fellow at JPL

Margaret Moerchen - now Science Deputy to the President of the Carnegie Institute of Science

Johan Mazoyer: I am interested in the imaging and study of the close vicinity of young stars, in which often hide debris disks and exoplanets. Both in simulation and experimentally on test beds, I develop wavefront control techniques which, associated to coronagraphs, achieve high contrast imaging in broad spectral bands. I also use image processing methods to detect and analyze circumstellar debris disks.

Charles Poteet: I am interested in understanding the physical processes responsible for shaping our Solar System and the nature of pre-planetary matter, the building blocks of planets. I have extensive experience in infrared spectroscopy using the Spitzer Space Telescope, in modeling silicate dust and ice absorption features, and in studying the evolution of these materials in both the interstellar medium and environments of active star formation.  I am currently using coronagraphic imaging polarimetry to characterize the dust properties of proto-planetary and debris disk systems.

Abhi Rajan: I am an observational astronomer interested in the detection and characterization of directly imaged exoplanets, specifically understanding the planetary properties through spectrophotometry of the planet's atmosphere in the near and mid-infrared. I am also interested in understanding brown dwarf atmospheres. For brown dwarfs I have studied their atmospheres via near-infrared photometric monitoring searches, looking for variations in the data potentially caused by weather variations.

Alumni - Research & Instrument Analysts

Abhijith Rajan  - from 2012 to 2017 a grad student at Arizona State University - and now returned to EPSIG as a postdoc.

Alumni - Staff

Neil Zimmerman: I apply modeling and optimization tools to high-contrast imaging problems, to maximize the scientific yield at both the instrument design and data processing stages. During my graduate work, I created the first data-cube extraction pipeline for an AO-fed, coronagraphic integral field spectrograph. More recently, I have concentrated my efforts on the coronagraph concept for the WFIRST mission. I designed a novel mask configuration for its characterization mode, to enable broadband spectroscopy of gas giant exoplanets in reflected starlight. Since joining STScI, I have teamed up with fellow EPSIG members to estimate the planet detection limits of the WFIRST coronagraph design, by using advanced starlight subtraction techniques on testbed data sets and end-to-end observatory simulations.

Nikole Lewis:  I'm an expert in exoplanet atmospheric characterization through both theory and observations. My work focuses on both transiting and directly imaged exoplanet investigations spanning Spitzer, Hubble, JWST, WFIRST, and ground-based facilities.

Johannes Sahlmann: My main research interests are the observational study of extrasolar planets and brown dwarfs (objects not massive enough to ignite hydrogen fusion), in particular their discovery and characterisation on the basis of optical/infrared observations with imaging, spectroscopic, and interferometric instruments. I specialize in the use of high-precision astrometry, that is the measurement of stellar positions in the sky plane, obtained from a variety of instruments on ground and in space. To make these measurements possible, I contribute to new instruments and surveys and I develop techniques that push the capabilities of existing facilities

Bob Brown: My research is about estimating the the scientific performance of future space missions, usually by means of the completeness metric. One focus is on missions that could directly detect and spectroscopically characterize currently known RV planets. Another is on TPF-type flagship missions, which are over the horizon. As a member of the Institute’s NIRCam team, still another focus is on the range of scientific applications that could be accomplished with the NIRCam coronagraphs.