A5077364412- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Optical Systems and Laser Technology
- Advanced optical system design
- Gamma-ray bursts and supernovae
- CCD and CMOS Imaging Sensors
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Astrophysical Phenomena and Observations
- Advanced Optical Sensing Technologies
- Spectroscopy and Laser Applications
- Spacecraft Design and Technology
- Inertial Sensor and Navigation
- Solar and Space Plasma Dynamics
- Infrared Target Detection Methodologies
- Molecular Spectroscopy and Structure
- Thermodynamic properties of mixtures
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Chemometric Analyses
- Spacecraft and Cryogenic Technologies
- Atmospheric Ozone and Climate
- Optical Wireless Communication Technologies
University of California, Santa Cruz
2024
Université Paris Cité
2020-2023
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2020-2023
Observatoire de Paris
2020-2023
National Astronomical Observatory of Japan
2018-2023
Subaru (Japan)
2019-2023
University College London
2020-2023
Centre National de la Recherche Scientifique
2020-2023
Sorbonne Université
2020-2023
Université Paris Sciences et Lettres
2020-2023
Abstract We present a comprehensive analysis of the Hubble Space Telescope observations atmosphere WASP-121 b, an ultra-hot Jupiter. After reducing transit, eclipse, and phase-curve with uniform methodology addressing biases from instrument systematics, sophisticated atmospheric retrievals are used to extract robust constraints on thermal structure, chemistry, cloud properties atmosphere. Our shows that consistent strong inversion beginning at ∼10 4 Pa dayside, solar subsolar metallicity Z...
Two studies utilizing sparse aperture masking (SAM) interferometry and $H_{\rm \alpha}$ differential imaging have reported multiple jovian companions around the young solar-mass star, LkCa 15 (LkCa bcd): first claimed direct detection of infant, newly-formed planets ("protoplanets"). We present new near-infrared imaging/spectroscopy from SCExAO system coupled with CHARIS integral field spectrograph multi-epoch thermal infrared Keck/NIRC2 at high Strehl ratios. These data provide look same...
We analyse the transmission and emission spectra of ultra-hot Jupiter WASP-76b, observed with G141 grism Hubble Space Telescope's Wide Field Camera 3 (WFC3). reduce fit raw data for each observation using open-source software Iraclis before performing a fully Bayesian retrieval publicly available analysis suite TauRex 3. Previous studies WFC3 WASP-76 b found hints titanium oxide (TiO) vanadium (VO) or non-grey clouds. Accounting fainter stellar companion to WASP-76, we reanalyse this show...
Abstract This paper presents the atmospheric characterization of three large, gaseous planets: WASP-127 b, WASP-79 and WASP-62 b. We analyzed spectroscopic data obtained with G141 grism (1.088–1.68 μ m) Wide Field Camera 3 on board Hubble Space Telescope using Iraclis pipeline TauREx3 retrieval code, both which are publicly available. For is least dense planet discovered so far located in short-period Neptune desert, our results found strong water absorption corresponding to an abundance...
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 analysis of the atmospheres 70 gaseous extrasolar planets via transit spectroscopy with Hubble’s Wide Field Camera 3 (WFC3). For over half these, we statistically detect spectral modulation that our retrievals attribute to molecular species. Among use Bayesian hierarchical modeling search for chemical trends bulk parameters. extracted water abundance infer atmospheric metallicity and compare it planet’s mass. also run equilibrium retrievals, fitting directly. However,...
ABSTRACT Retrieval methods are a powerful analysis technique for modelling exoplanetary atmospheres by estimating the bulk physical and chemical properties that combine in forward model to best fit an observed spectrum, they increasingly being applied observations of directly imaged exoplanets. We have adapted taurex3, Bayesian retrieval suite, near-infrared spectrophotometry from gas giant exoplanets brown dwarfs. demonstrate taurex3’s applicability sub-stellar presenting results dwarf...
Abstract We present follow-up SCExAO/CHARIS H- and K -band ( R ∼ 70) high-contrast integral field spectroscopy Keck/NIRC2 photometry of directly imaged brown dwarf companion HD 33632 Ab new radial-velocity data for the system from SOPHIE spectrograph, complemented by Hipparcos Gaia astrometry. These enable more robust spectral characterization compared to lower-resolution spectra discovery paper than double available astrometric baseline. Ab’s spectrum is well reproduced a L8.5–L9.5 dwarf....
We present SCExAO/CHARIS high-contrast imaging/$JHK$ integral field spectroscopy of $\kappa$ And b, a directly-imaged low-mass companion orbiting nearby B9V star. detect b at high signal-to-noise and extract precision spectrophotometry using new forward-modeling algorithm for (A-)LOCI complementary to KLIP-FM developed by Pueyo (2016). b's spectrum best resembles that low-gravity L0--L1 dwarf (L0--L1$\gamma$). Its luminosity are very well matched 2MASSJ0141-4633 several other 12.5--15...
The compute and control for adaptive optics (cacao) package is an open-source modular software environment real-time of modern system. By leveraging many-core CPU GPU hardware, it can scale up to meet the demanding computing requirements current future high frame rate, actuator count (AO) systems. cacao's design enables both simple/barebone operation, complex full-featured AO centered on data streams that hold in shared memory along with a synchronization mechanism processes. Users...
The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is an extremely modular high- contrast installed on the telescope in Hawaii. SCExAO has a dual purpose. Its position northern hemisphere 8-meter makes it prime for detection and characterization of exoplanets stellar environments over large portion sky. In addition, SCExAO's unique design ideal to test innovative technologies algorithms quickly laboratory setup subsequently deploy them on-sky. benefits from first stage...
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...
We present an atmospheric characterization study of two medium sized planets bracketing the radius Neptune: HD 106315 c (R$_{\rm{P}}$=4.98 $\pm$ 0.23 R$_{\oplus}$) and 3167 (R$_{\rm{P}}$=2.740$_{-0.100}^{+0.106}$ R$_{\oplus}$). analyse spatially scanned spectroscopic observations obtained with G141 grism (1.125 - 1.650 $\mu$m) Wide Field Camera 3 (WFC3) onboard Hubble Space Telescope. use publicly available Iraclis pipeline TauREx3 retrieval code we detect water vapor in atmosphere both...
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...
Abstract We present an atmospheric analysis of LTT 9779 b, a rare planet situated in the hot-Neptune desert, that has been observed with Hubble Space Telescope (HST)/WFC3 G102 and G141. The combined transmission spectrum, which covers 0.8–1.6 μ m, shows gradual increase transit depth wavelength. Our preferred model evidence for H 2 O, CO , FeH significance 3.1 σ 2.4 2.1 respectively. In attempt to constrain rate escape this planet, we search 1.083 m helium line data but find no excess...
Abstract We present new, near-infrared (1.1–2.4 μ m) high-contrast imaging of the debris disk around HD 15115 with Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled High Angular Resolution Imaging Spectrograph (CHARIS). The SCExAO/CHARIS resolves down to ρ ∼ 0.″2 ( r proj 10 au), a factor ∼3–5 smaller than previous recent studies. derive position angle PA 279.°4–280.°5 and an inclination i 85.°3–86.2.°. While SPHERE/IRDIS imagery could suggest significantly misaligned...
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...
[abridged] We analyzed mid-infrared high-contrast coronagraphic images of the beta Pictoris system, taking advantage NEAR experiment using VLT/VISIR instrument. The goal our analysis is to investigate both detection planet b and disk features at mid-IR wavelengths. In addition, by combining several epochs observation, we expect constrain position known clumps improve knowledge on dynamics disk. To evaluate flux contribution, extracted photometry compared it published in literature. used...
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...
We present early laboratory simulations and extensive on-sky tests validating of the performance a shaped pupil coronagraph (SPC) behind an extreme-AO corrected beam Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. In with SCExAO internal source/wavefront error simulator, normalized intensity profile for SPC degrades more slowly than Lyot as low-order aberrations reduce Strehl ratio from extremely high values (S.R. $\sim$ 0.93--0.99) to those characteristic current ground-based...
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 the analysis of atmospheres 70 gaseous extrasolar planets via transit spectroscopy with Hubble's Wide Field Camera 3 (WFC3). For over half these, we statistically detect spectral modulation which our retrievals attribute to molecular species. Among use Bayesian Hierarchical Modelling search for chemical trends bulk parameters. extracted water abundance infer atmospheric metallicity and compare it planet's mass. also run equilibrium retrievals, fitting directly. However, although...
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,...