A5051178711- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Optical Systems and Laser Technology
- Astronomical Observations and Instrumentation
- Advanced optical system design
- Optical Coherence Tomography Applications
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Spacecraft and Cryogenic Technologies
- Astrophysics and Star Formation Studies
- Photonic Crystal and Fiber Optics
- CCD and CMOS Imaging Sensors
- Photonic and Optical Devices
- Advanced Optical Sensing Technologies
- Recommender Systems and Techniques
- Network Time Synchronization Technologies
- Optical Wireless Communication Technologies
- Multimedia Communication and Technology
- Mobile and Web Applications
- Particle Detector Development and Performance
University of Notre Dame
2015-2024
The Ohio State University
2023-2024
University of Cambridge
2012-2016
We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: cross-dispersed echelle that operates in YJ-bands (0.97-1.30 microns), fiber-injection acquisition camera system, wavelength calibration unit. iLocater will deliver high spectral resolution (R~150,000-240,000) measurements permit novel studies of stellar substellar objects solar neighborhood including extrasolar planets. Unlike...
Abstract We report the results from a pilot study to search for black holes and other dark companions in binary systems using direct imaging with SHARK-VIS iLocater pathfinder “Lili” on Large Binocular Telescope. Starting known single-lined spectroscopic binaries, we select high mass functions that could host whose orbits indicate projected orbital separation ≥30 mas. For this first exploration, selected four (HD 137909, HD 104438, 117044, 176695). In each case, identify luminous companion...
Precise mass measurements of exoplanets discovered by the direct imaging or transit technique are required to determine planet bulk properties and potential habitability. Furthermore, it is generally acknowledged that, for foreseeable future, Extreme Precision Radial Velocity (EPRV) measurement only method potentially capable detecting measuring masses orbits habitable-zone Earths orbiting nearby F, G, K spectral-type stars from ground. In particular, EPRV with a precision better than...
Abstract Precise radial velocity (PRV) surveys are important for the search Earth analogs around nearby bright stars, which induce a small stellar reflex motion with an RV amplitude of ∼10 cm s −1 . Detecting such signal poses challenges to instrumentation, data analysis, and precision astrophysical models mitigate jitter. In this work, we investigate component in PRV error budget—the spectral contamination from Earth’s atmosphere (tellurics). We characterize effects telluric absorption on...
We report high spatial resolution i' band imaging of the multiple T Tauri system LkHα 262/LkHα 263 obtained during first commissioning period Adaptive Optics Lucky Imager (AOLI) at 4.2-m William Herschel Telescope, using its Imaging mode. AOLI images have provided photometry for each two components A and B (0.41 arcsec separation) marginal evidence an unresolved binary or a disc in 262. The data combined with previously available newly optical infrared show that three are comoving, there is...
The demonstration of efficient single-mode fiber (SMF) coupling is a key requirement for the development compact, ultra-precise radial velocity (RV) spectrograph. iLocater next generation instrument Large Binocular Telescope (LBT) that uses adaptive optics (AO) to inject starlight into SMF. In preparation commissioning iLocater, prototype SMF injection system was installed and tested at LBT in Y-band (0.970-1.065 $\mu$m). This designed verify capability AO as well characterize on-sky...
Single-mode fiber (SMF) spectrographs fed with adaptive optics (AO) offer a unique path for achieving extremely precise radial velocity (EPRV) measurements. We present (RV) error budget based on end-to-end numerical simulations of an instrument named iLocater that is being developed the Large Binocular Telescope (LBT). Representing first AO-fed, SMF spectrograph, iLocater's design used to quantify and assess relative advantages drawbacks Doppler time series measurements made at diffraction...
Enabling efficient injection of light into single-mode fibers (SMFs) is a key requirement in realizing diffraction-limited astronomical spectroscopy on ground-based telescopes. SMF-fed spectrographs, facilitated by the use adaptive optics (AO), offer distinct advantages over comparable seeing-limited designs, including higher spectral resolution within compact and stable instrument volume, telescope independent spectrograph design. iLocater an extremely precise radial velocity (EPRV) being...
We introduce a design for tip-tilt sensor with integrated single-mode fiber coupling use the front-end prototype of iLocater spectrograph at Large Binocular Telescope to detect vibrations that occur within optical train. This is made up micro-lens array printed on top bundle consisting central and six surrounding multi-mode fibers. The in based previous utilized multi-core seven With this updated design, we are able achieve better sensing throughput. report modeled performance: if beam...
Optimizing on-sky single-mode fiber (SMF) injection is an essential part of developing precise Doppler spectrometers and new astrophotonics technologies. We installed tested a prototype SMF-injection system at the Large Binocular Telescope in 2016 April. The unit was built as derisking process for instrument named iLocater that will use adaptive optics (AO) to feed high resolution, near-infrared spectrograph. In this paper we report Y-band SMF coupling measurements bright, M-type stars....
The highest resolution images ever taken in the visible were obtained by combining Lucky Imaging and low order adaptive optics. This paper describes a new instrument to be deployed on WHT 4.2m GTC 10.4 m telescopes La Palma, with particular emphasis optical design expected system performance. A of wavefront sensor using photon counting CCD detectors multi-plane curvature will allow dramatically fainter reference stars used, allowing virtually full sky coverage natural guide star. also...
We have recently initiated a multi-institutional research program that will examine existing pipelines and catalog potential sources of variation in their resulting RV measurements. Through series EPRV community meetings we aim to establish recommended, standardized formats for data products develop/distribute the tools necessary direct comparisons between modern instruments. This lay groundwork modular, open source, analysis toolbox be compatible with wide variety current future Here...
Abstract Precision radial velocity spectrographs that use adaptive optics (AO) show promise to advance telescope observing capabilities beyond those of seeing-limited designs. We are building a spectrograph for the Large Binocular Telescope (LBT) named iLocater uses AO inject starlight directly into single mode fibers. iLocater's first acquisition camera system (the SX camera), which receives light from one 8.4 m diameter primary mirrors LBT, was initially installed in summer 2019 and has...
ABSTRACT Diffraction-limited radial-velocity instruments offer a pathway towards improved precision and stability, the exploration of new parameter spaces at high spatial spectral resolution. However, achieving necessary performance requires careful instrument design considerable on-sky testing. We describe construction ‘Little iLocater’ (Lili), compact spectrograph that has been used to validate front-end fibre-injection system iLocater spectrograph. present design, assembly, using data...
At wavelengths longwards of the sensitivity silicon, hybrid structured mercury-cadmium-telluride (HgCdTe) detectors show promise to enable extremely precise radial velocity (RV) measurements late-type stars. The most advanced near infrared (NIR) detector commercially available is HAWAII series (HxRG) NIR detectors. While quantum efficiency such devices has been shown be approx ninety percent, noise characteristics these devices, and how they relate RV measurements, have yet quantified. We...
The Adaptive Optics Lucky Imager (AOLI) is a new instrument under development to demonstrate near diffraction limited imaging in the visible on large ground-based telescopes. We present adaptive optics system being designed for comprising stroke deformable mirror, fixed component non-linear curvature wavefront sensor and photon-counting EMCCD detectors. describe optical design of where two photoncounting CCDs provide total four reference images. Simulations characteristics are discussed,...
iLocater is a near-infrared (NIR) radial velocity (RV) spectrograph that being developed for the Large Binocular Telescope in Arizona. Unlike seeing-limited designs, uses adaptive optics to inject starlight directly into single-mode fiber. This feature offers high spectral resolution while simultaneously maintaining compact optical design. Although this approach shows promise generate extremely precise RV measurements, it differs from conventional Doppler spectrographs, and therefore carries...
Lucky Imaging combined with a low order adaptive optics system has given the highest resolution images ever taken in visible or near infrared of faint astronomical objects. This paper describes new instrument that already been deployed on WHT 4.2m telescope La Palma, particular emphasis optical design and predicted performance. A wavefront sensor using photon counting CCD detectors multi-plane curvature will allow virtually full sky coverage natural guide stars. With 2 x array 1024 EMCCDs,...
EarthFinder is a NASA Astrophysics Probe mission concept selected for study as input to the 2020 National Academies Decadal Survey. The based on dramatic shift in our understanding of how PRV measurements should be made. We propose new paradigm which brings high precision, cadence domain transit photometry demonstrated by Kepler and TESS challenges at cm/s level. This takes advantage of: 1) broad wavelength coverage from UV NIR only possible space minimize effects stellar activity; 2)...
iLocater is a near-infrared, extremely precise radial velocity (EPRV) spectrograph under construction for the dual 8.4 m diameter Large Binocular Telescope (LBT). The instrument will undertake precision studies of Earth-like planets orbiting low-mass stars. Operating in diffraction-limited regime, uses adaptive optics to efficiently inject starlight directly into single-mode fibers that illuminate high spectral resolution (R=190,500 median), cryogenic, spectrograph. To maximize performance,...
EarthFinder is a Probe Mission concept selected for study by NASA input to the 2020 astronomy decadal survey. This currently active and final white paper report due at end of calendar 2018. We are tasked with evaluating scientific rationale obtaining precise radial velocity (PRV) measurements in space, which two-part inquiry: What can be gained from going space? can't done form ground? These two questions flow down these specific tasks our - Identify limit, if any, introduced micro-...
In this paper we present the Adaptive Optics Lucky Imager (AOLI), a state-of-the-art instrument which makes use of two well proved techniques for extremely high spatial resolution with ground-based telescopes: Imaging (LI) and (AO). AOLI comprises an AO system, including low order non-linear curvature wavefront sensor together 241 actuators deformable mirror, science array four 1024x1024 EMCCDs, allowing 120x120 down to 36x36 arcseconds field view, calibration subsystem powerful LI software....
Many adaptive optics (AO) systems in use today require the of bright reference objects to determine effects atmospheric distortions. Typically these Shack-Hartmann Wavefront sensors (SHWFS) distribute incoming light from a object between large number sub-apertures. Guyon et al. evaluated sensitivity several different wavefront sensing techniques and proposed non-linear Curvature Sensor (nlCWFS) offering improved across range orders distortion. On ground-based telescopes this can provide...
Existing planet-finding spectrometers are limited by systematic errors that result from their seeing-limited design. Of particular concern is the use of multi-mode fibers (MMFs), which introduce modal noise and accept significant amounts background radiation sky. We present design a single-mode fiber-based acquisition camera for diffraction-limited spectrometer named "iLocater." By using "extreme" adaptive optics (AO) system Large Binocular Telescope (LBT), iLocater will overcome limitations...