A5073903719- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Astronomy and Astrophysical Research
- Photonic and Optical Devices
- Optical Coherence Tomography Applications
- Spacecraft Design and Technology
- Space Satellite Systems and Control
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Optical Systems and Laser Technology
- Advanced Optical Sensing Technologies
- Solar and Space Plasma Dynamics
- Spectroscopy and Laser Applications
- Photonic Crystals and Applications
- Advanced Fiber Optic Sensors
- Advanced Fiber Laser Technologies
- Geophysics and Gravity Measurements
- Photonic Crystal and Fiber Optics
- Optical Network Technologies
- Spacecraft and Cryogenic Technologies
- Advanced optical system design
- Optical Polarization and Ellipsometry
- Inertial Sensor and Navigation
- Satellite Image Processing and Photogrammetry
- Advanced Fluorescence Microscopy Techniques
California Institute of Technology
2017-2025
American Institute of Aeronautics and Astronautics
2019-2024
Massachusetts Institute of Technology
2019-2024
Space Telescope Science Institute
2024
IIT@MIT
2019
Jet Propulsion Laboratory
2017
Abstract M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M also good analogs the youngest substellar companions, which share similar T eff ∼ 2300–2800 K. We present analyses for M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution ( R 35,000) K -band spectroscopy. First, by including KPIC relative radial velocities between secondary in orbit fit, we improve dynamical mass precision 60% find <?CDATA...
Photonics offer numerous functionalities that can be used to realize astrophotonic instruments. The most spectacular example date is the ESO Gravity instrument at Very Large Telescope in Chile. Integrated devices stand critical advantages for development, including extreme miniaturization, as well integration, superior thermal and mechanical stabilization owing small footprint, high replicability offering cost savings. Numerous technologies have been developed address shortcomings of...
Abstract We present high-resolution K -band emission spectra of the quintessential hot Jupiter HD 189733 b from Keck Planet Imager and Characterizer. Using a Bayesian retrieval framework, we fit dayside pressure–temperature profile, orbital kinematics, mass-mixing ratios H 2 O, CO, CH 4 , NH 3 HCN, S, 13 CO/ 12 CO ratio. measure mass fractions <?CDATA ${\mathrm{logH}}_{2}{\rm{O}}=-{2.0}_{-0.4}^{+0.4}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub>...
Abstract We present Keck/KPIC Phase II K -band observations of the nontransiting hot Jupiter HD 143105 b. Using a cross-correlation approach, we make first detection planetary atmosphere at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>K</mml:mi> <mml:mi mathvariant="normal">p</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>18</mml:mn> <mml:msubsup> <mml:mn>5</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>13</mml:mn> </mml:mrow>...
Abstract We present the first on-sky segmented primary mirror closed-loop piston control using a Zernike wavefront sensor (ZWFS) installed on Keck II telescope. Segment cophasing errors are contributor to contrast limits and will be necessary correct for next generation of space missions ground-based extremely large telescopes, which all have mirrors. The goal ZWFS is monitor in parallel with science observations. ideal measuring phase discontinuities such as segment one most sensitive WFSs,...
Abstract Photonic lanterns (PLs) are tapered waveguides that gradually transition from a multimode fiber geometry to bundle of single-mode fibers (SMFs). They can efficiently couple telescope light into entrance at the focal plane and convert it multiple beams. Thus, each SMF samples its unique mode (lantern principal mode) in pupil, analogous subapertures aperture masking interferometry (AMI). Coherent imaging with PLs be enabled by interference outputs applying phase modulation, which...
Abstract We present the projected rotational velocity and molecular abundances for HD 33632 Ab obtained via Keck Planet Imager Characterizer (KPIC) high-resolution spectroscopy. is a nearby benchmark brown dwarf companion at separation of ∼20 au that straddles L–T transition. Using forward-modeling framework with on-axis host star spectra, which provides self-consistent substellar atmospheric retrieval models Ab, we derive 53 ± 3 km s −1 carbon monoxide water mass fractions logCO = −2.3 0.3...
Micro-Electro-Mechanical Systems (MEMS) Deformable Mirrors (DMs) enable precise wavefront control for optical systems. This technology can be used to meet the extreme requirements high contrast imaging of exoplanets with coronagraph instruments. MEMS DM is being demonstrated and developed in preparation future exoplanet space telescopes, including Wide Field Infrared Survey Telescope (WFIRST) mission which supported development a 2040 actuator DM. In this paper, we discuss ground testing...
The photonic lantern (PL) is a tapered waveguide that can efficiently couple light into multiple single-mode optical fibers. Such devices are currently being considered for number of tasks, including the coupling telescopes and high-resolution, fiber-fed spectrometers, coherent detection, nulling interferometry, vortex-fiber (VFN). In conjunction with these use cases, PLs simultaneously perform low-order focal-plane wavefront sensing. this work, we provide mathematical framework analysis...
We present an atmospheric characterization and orbital analysis of HD 206893 B, exceptionally red, L/T-transition substellar companion in a multiplanetary system, via Keck Planet Imager Characterizer (KPIC) high-resolution (R $\sim$ 35,000) K-band spectroscopy. Using PHOENIX models forward-model framework that fits the spectrum diffracted starlight simultaneously, we detect B at $>8\sigma$ significance cross-correlation two epochs. find effective temperature for $1634^{+72}_{-38}$ K log(g)...
The Keck Planet Imager and Characterizer (KPIC) is a series of upgrades for the II Adaptive Optics (AO) system NIRSPEC spectrograph to enable diffraction limited, high resolution (R>30000) spectroscopy exoplanets low mass companions in K L bands. Phase I consisted single mode fiber injection/extraction units (FIU/FEU) used conjunction with H band pyramid wavefront sensor. use fibers provides gain stellar rejection, substantial reduction sky background, an extremely stable line spread...
Abstract We present an atmospheric characterization and orbital analysis of HD 206893 B, exceptionally red, L/T-transition substellar companion in a multiplanetary system, via Keck Planet Imager Characterizer (KPIC) high-resolution ( R ∼ 35,000) K- band spectroscopy. Using PHOENIX models forward-model framework that fits the spectrum diffracted starlight simultaneously, we detect B at >8 σ significance cross correlation two epochs. find effective temperature for 1634 <mml:math...
Abstract We present atmospheric retrievals from Keck/KPIC Phase II observations of the ultrahot Jupiter (UHJ) KELT-20/MASCARA-2 b. Previous free molecular abundances for UHJs have been impacted by significant model biases due to variations in vertical abundance profiles, which we address including dissociation into our retrieval framework as an additional parameter. measure CO ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:msub>...
Adaptive optics (AO) systems are critical in any application where highly resolved imaging or beam control must be performed through a dynamic medium. Such applications include astronomy and free-space optical communications, light propagates the atmosphere, as well medical microscopy vision science, biological tissues. Recent works have demonstrated common-path wavefront sensors (WFSs) for adaptive using photonic lantern (PL), slowly varying waveguide that can efficiently couple multi-moded...
Coupling a high-contrast imaging instrument to high-resolution spectrograph has the potential enable most detailed characterization of exoplanet atmospheres, including spin measurements and Doppler mapping. The system serves as spatial filter separate light from star planet while acts spectral filter, which differentiates between features in stellar planetary spectra. Keck Planet Imager Characterizer (KPIC) located downstream current W. M. II adaptive optics (AO) will contain fiber injection...
The Keck Planet Imager and Characterizer (KPIC) is a series of upgrades for the II Adaptive Optics (AO) system NIRSPEC spectrograph to enable diffraction-limited, high-resolution ($R>30,000$) spectroscopy exoplanets low-mass companions in K L bands. Phase I consisted single-mode fiber injection/extraction units (FIU/FEU) used conjunction with an H-band pyramid wavefront sensor. II, deployed commissioned 2022, adds 1000-actuator deformable mirror, beam-shaping optics, vortex coronagraph,...
Abstract Coronagraphs allow for faint off-axis exoplanets to be observed, but are limited angular separations greater than a few beam widths. Accessing closer-in would greatly increase the expected number of detectable planets, which scales inversely with inner working angle. The vortex fiber nuller (VFN) is an instrument concept designed characterize within single width. It requires optical elements and compatible many coronagraph designs as complementary characterization tool. However,...
Vortex fiber nulling (VFN) is a single-aperture interferometric technique for detecting and characterizing exoplanets separated from their host star by less than diffracted beam width. VFN uses vortex mask single-mode to selectively reject starlight while coupling off-axis planet light with simple optical design that can be readily implemented on existing direct imaging instruments feed an fiber. With its axially symmetric region peaking within the inner working angle of conventional...
Linking a coronagraph instrument to spectrograph via single-mode optical fiber is pathway toward detailed characterization of exoplanet atmospheres with current and future ground- space-based telescopes. However, given the extreme brightness ratio small angular separation between planets their host stars, planet signal-to-noise will likely be limited by unwanted coupling starlight into fiber. To address this issue, we utilize wavefront control loop deformable mirror systematically reject...
Abstract The accumulation of aberrations along the optical path in a telescope produces distortions and speckles resulting images, limiting performance cameras at high angular resolution. It is important to achieve highest possible sensitivity faint sources, using both hardware data analysis software. While analytic methods are efficient, real systems better modeled numerically, but numerical models complicated with many parameters can be hard understand, optimize, apply. Automatic...
Abstract The direct imaging of an Earth-like exoplanet will require sub-nanometric wave-front control across large light-collecting apertures to reject host starlight and detect the faint planetary signal. Current adaptive optics systems, which use sensors that reimage telescope pupil, face two challenges prevent this level control: non-common-path aberrations, caused by differences between sensing science arms instrument; petaling modes: discontinuous phase aberrations pupil fragmentation,...
Abstract Vortex fiber nulling (VFN) is a technique for detecting and characterizing faint companions at small separations from their host star. A near-infrared (∼2.3 μ m) VFN demonstrator mode was deployed on the Keck Planet Imager Characterizer (KPIC) instrument Observatory presented earlier. In this Letter, we present first companion detections. Three targets, HIP 21543 Ab, 94666 50319 B, were detected with host–companion flux ratios between 70 430 within one diffraction beamwidth ( λ / D...
We present the projected rotational velocity and molecular abundances for HD 33632 Ab obtained via Keck Planet Imager Characterizer high-resolution spectroscopy. is a nearby benchmark brown dwarf companion at separation of $\sim$20 au that straddles L/T transition. Using forward-modeling framework with on-axis host star spectra, self-consistent substellar atmospheric retrieval models Ab, we derive 53 $\pm$ 3 km/s carbon/water mass fractions log CO = $-$2.3 0.3 H$_2$O $-$2.7 0.2. The inferred...