A5089666756- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Optical Systems and Laser Technology
- Astrophysics and Star Formation Studies
- Advanced optical system design
- Astro and Planetary Science
- Calibration and Measurement Techniques
- Optical Coherence Tomography Applications
- Optical Wireless Communication Technologies
- CCD and CMOS Imaging Sensors
- Advanced Optical Sensing Technologies
- Photonic and Optical Devices
- Optical Polarization and Ellipsometry
- Gamma-ray bursts and supernovae
- Semiconductor Lasers and Optical Devices
- Optical Network Technologies
- Astronomical Observations and Instrumentation
- Laser Material Processing Techniques
- Advanced Fiber Optic Sensors
- Optical measurement and interference techniques
- Inertial Sensor and Navigation
- Geophysics and Gravity Measurements
- Infrared Target Detection Methodologies
- Solar and Space Plasma Dynamics
National Astronomical Observatory of Japan
2020-2025
Subaru (Japan)
2020-2025
National Institutes of Natural Sciences
2021-2024
Canada–France–Hawaii Telescope
2022-2023
Sorbonne Université
2017-2022
Université Paris Cité
2017-2022
Centre National de la Recherche Scientifique
2017-2022
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2017-2022
Observatoire de Paris
2018-2022
Las Cumbres Observatory Global Telescope Network
2021
Abstract We present the direct-imaging discovery of a substellar companion in orbit around Sun-like star member Hyades open cluster. So far, no other companions have been unambiguously confirmed via direct imaging main-sequence stars Hyades. The HIP 21152 is an accelerating as identified by astrometry from Gaia and Hipparcos satellites. detected companion, B, multiple epochs using high-contrast SCExAO/CHARIS Keck/NIRC2. also obtained stellar radial-velocity data Okayama 188 cm telescope....
Direct imaging of gas giant exoplanets provides information on their atmospheres and the architectures planetary systems. However, few planets have been detected in blind surveys with direct imaging. Using astrometry from Gaia Hipparcos spacecraft, we identified dynamical evidence for a planet around nearby star HIP 99770. We confirmed detection this using Subaru Coronagraphic Extreme Adaptive Optics instrument. The planet, 99770 b, orbits 17 astronomical units its host star, receiving an...
Abstract We present the direct imaging discovery of a substellar companion to nearby Sun-like star, HD 33632 Aa, at projected separation ∼20 au, obtained with SCExAO/CHARIS integral field spectroscopy complemented by Keck/NIRC2 thermal infrared imaging. The companion, Ab, induces 10.5 σ astrometric acceleration on star as detected Gaia and Hipparcos satellites. JHK (1.1–2.4 μ m) spectra L p (3.78 photometry are best matched L/T transition object: an older, higher-gravity, less dusty...
Abstract Characterisation of exoplanets is key to understanding their formation, composition and potential for life. Nulling interferometry, combined with extreme adaptive optics, among the most promising techniques advance this goal. We present an integrated-optic nuller whose design directly scalable future science-ready interferometric nullers: Guided-Light Interferometric Technology, deployed at Subaru Telescope. It combines four beams delivers spatial spectral information. demonstrate...
Abstract We report the direct imaging discovery of a low-mass companion to nearby accelerating A star, HIP 109427, with Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument coupled Microwave Kinetic Inductance Detector Exoplanet Camera (MEC) and CHARIS integral field spectrograph. data reduced reference star point spread function (PSF) subtraction yield 1.1–2.4 μ m spectra. MEC reveals in Y J band at comparable signal-to-noise ratio using stochastic speckle discrimination, no PSF...
Context. Exoplanet direct imaging is a key science goal of current ground-based telescopes as well future extremely large and space-based telescopes. Several high-contrast (HCI) systems for exoplanet have been developed are implemented on Despite recent developments in HCI systems, the contrast they deliver limited by non-common path aberrations (NCPAs) residual wavefront errors adaptive optics (AO) system. To overcome this limitation reach higher contrast, need focal plane wavefront-sensing...
Abstract Recent high-sensitivity observations reveal that accreting giant planets embedded in their parental circumstellar disks can emit H α at final formation stages. While the origin of this emission is not yet determined, magnetospheric accretion currently most plausible hypothesis. In order to test hypothesis further, we develop a simplified but physics-based model and apply it our taken toward HD 163296 with Subaru/SCExAO+VAMPIRES. We specify under which conditions undergo hydrogen...
The pyramid wavefront sensor (PWFS) is the currently preferred design for high-sensitivity adaptive optics (AO) systems extremely large telescopes (ELTs). Yet, nonlinearities of signal retrieved from PWFS pose a significant problem achieving full correction potential using this sensor, that will only worsen with increasing dimension telescopes. This paper investigates so-called optical gain (OG) phenomenon, sensitivity reduction and an overall modification response induced by residual...
Context. The pyramid was proven to be a highly sensitive and versatile wave-front sensor (WFS) has been selected installed on the single conjugate adaptive optics (AO) systems of extremely large telescope (ELT). pupil ELT is fragmented by secondary support spider arms, which are larger than spatial coherence length atmospheric turbulence. This causes rupture incoming wavefront continuity, means that we need able measure differential pistons across arms achieve full reconstruction. Aims. We...
Abstract We present the direct-imaging discovery of a substellar companion (a massive planet or low-mass brown dwarf) to young, γ Doradus ( Dor)-type variable star HIP 39017 (HD 65526). The companion’s SCExAO/CHARIS JHK (1.1–2.4 μ m) spectrum and Keck/NIRC2 <?CDATA $L^{\prime} $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>L</mml:mi> <mml:mo accent="false">′</mml:mo> </mml:math> photometry indicate that it is an L/T transition object. A comparison + L...
Traditional wavefront control in high-energy, high-intensity laser systems usually lacks real-time capability, failing to address dynamic aberrations. This limits experimental accuracy due shot-to-shot fluctuations and necessitates long cool-down phases mitigate thermal effects, particularly as higher repetition rates become essential, e.g. Inertial Fusion research. paper details the development implementation of a capable adaptive optics system at Apollon facility. Inspired by astronomical...
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...
We describe the current on-sky performance of Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument on telescope Maunakea, Hawaii. SCExAO is continuing to advance its AO performance, delivering H band Strehl ratios in excess 0.9 for bright stars. new advances with SCExAO's wavefront control that lead a more stable corrected and diffraction-limited imaging optical, modifications code better handle read noise suppression within CHARIS, tests spectrophotometric precision accuracy...
Abstract The pyramid wave front sensor (PyWFS) has become increasingly popular to use in adaptive optics (AO) systems due its high sensitivity. main drawback of the PyWFS is that it inherently nonlinear, which means classic linear reconstruction techniques face a significant reduction performance at errors, particularly when unmodulated. In this paper, we consider potential neural networks (NNs) replace widely used matrix vector multiplication (MVM) control. We aim test hypothesis NN's...
MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The instrument's capabilities focus on imaging (including astrometric and high contrast) as well single object spectroscopy. This contribution looks how requirements from observing modes have driven instrument design functionality. Using examples specific science cases, making use of data simulation tool, an outline is presented what we can expect achieve.
After 16 years of on-sky operation, Subaru Telescope's facility adaptive optics AO188 is getting several major upgrades to become the extreme-AO AO3000 (3000 actuators in pupil compared 188 previously). will provide high-Strehl images for instruments from visible mid-infrared, notably Infrared Camera and Spectrograph (IRCS), Coronagraphic Extreme Adaptive Optics (SCExAO). For this upgrade, original 188-element deformable mirror (DM) be replaced with ALPAO's 64 × DM. The wavefront sensor also...
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,...
We present the direct-imaging discovery of a substellar companion (a massive planet or low-mass brown dwarf) to young, $\gamma$ Doradus-type variable star, HIP 39017 (HD 65526). The companion's SCExAO/CHARIS JHK ($1.1-2.4\mu$m) spectrum and Keck/NIRC2 L$^{\prime}$ photometry indicate that it is an L/T transition object. A comparison JHK+L$^{\prime}$ several atmospheric model grids finds significantly better fit cloudy models than cloudless models. Orbit modeling with relative astrometry...
The COMPASS platform was designed to meet the need for high-performance simulation of AO systems. Taking advantage specific hardware architecture GPU, tool allows scientist obtain adequate execution speeds and conduct large campaigns scaled E-ELT dimensioning a variety flavors from SCAO MOAO. On latest GPU (NVIDA Volta), several hundreds short exposure PSF per second can be achieved system on E-ELT, making real-time end-to-end tool. In this paper, we provide full description critical...
We present the direct imaging discovery of a low-mass companion to nearby accelerating F star, HIP 5319, using SCExAO coupled with CHARIS, VAMPIRES, and MEC instruments in addition Keck/NIRC2 imaging. CHARIS $JHK$ (1.1-2.4 $\mu$m) spectroscopic data combined VAMPIRES 750 nm, $Y$, NIRC2 $L_{\rm p}$ photometry is best matched by an M3--M7 object effective temperature T=3200 K surface gravity log($g$)=5.5. Using relative astrometry for 5319 B from absolute primary $Gaia$ $Hipparcos$ adopting...
We present first results from a new exoplanet direct imaging survey being carried out with the Subaru Coronagraphic Extreme Adaptive Optics project coupled CHARIS integral field spectrograph. Our targeting stars showing evidence for statistically significant astrometric acceleration Hipparcos and Gaia satellites implying existence of substellar or planetary companions at sub-arcsecond separations.. JHK low-resolution spectra constrain newly-discovered companion spectral types, temperatures,...
Context. Differentiating between a true exoplanet signal and residual speckle noise is key challenge in high-contrast imaging (HCI). Speckles result from combination of fast, slow, static wavefront aberrations introduced by atmospheric turbulence instrument optics. While control techniques developed over the last decade have shown promise minimizing fast residuals, slow such as non-common path (NCPAs) remain limiting factor for detection. NCPAs are not seen sensor (WFS) adaptive optics (AO)...
We propose the Correlation-Locking Optimization SchEme (CLOSE), a real-time adaptive filtering technique for optics (AO) systems controlled with integrators. CLOSE leverages temporal autocorrelation of modal signals in controller telemetry and drives gains integral command law closed servo-loop. This supervisory loop is configured using only few scalar parameters, automatically controls to closely match transfer functions achieving minimum variance control. optimization proven work...
MICADO is the European ELT first-light imager, working in near-infrared at telescope diffraction limit. Provided by MAORY, adaptive optics module (AO), MCAO will be primary AO mode of MICADO, driving design instrument. also come with a SCAO capability. Developed under MICADO's responsibility and jointly first to tested telescope, phased approach integration ELT. The MICADO-MAORY preliminary review (PDR) occur November 2018. We present here different activities results we have had past two...