A5038744947- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Space Science and Extraterrestrial Life
- Planetary Science and Exploration
- Calibration and Measurement Techniques
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Photocathodes and Microchannel Plates
- Semiconductor materials and devices
- Advanced optical system design
- Optical Polarization and Ellipsometry
- Electronic and Structural Properties of Oxides
- Photoacoustic and Ultrasonic Imaging
- Surface Roughness and Optical Measurements
- Optical Systems and Laser Technology
- Geophysics and Gravity Measurements
- Particle accelerators and beam dynamics
- Advanced Optical Sensing Technologies
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
University of California, San Diego
2020-2024
Harvard University
2023
University of California, Santa Cruz
2023
University of Delaware
2023
University of California, Berkeley
2023
Center for Astrophysics Harvard & Smithsonian
2023
University of Colorado Boulder
2017-2018
Laboratory for Atmospheric and Space Physics
2017
Recent advances in the physical vapor deposition (PVD) of protective fluoride films have raised far-ultraviolet (FUV: 912-1600 {\AA}) reflectivity aluminum-based mirrors closer to theoretical limit. The greatest gains, at more than 20%, come for lithium fluoride-protected aluminum, which has shortest wavelength cutoff any conventional overcoat. Despite success NASA FUSE mission, use (LiF)-based optics is rare, as LiF hygroscopic and requires handling procedures that can drive risk. With now...
Abstract We present results for 19 galaxies in the redshift range 1.2 ≲ z 2.6 to model star formation rate (SFR) and stellar mass using galactic spectral energy distributions. With W. M. Keck Observatory MOSFIRE we spectroscopically confirm redshifts lines of H α , which are further used SFR calculations. Our observed modeled SFRs reasonable agreement, validating parameters produced by application Code Investigating GALaxy Emission population synthesis software observations high-redshift galaxies.
We present a survey of the central region nearest starburst galaxy, IC 10, using W. M. Keck Observatory Cosmic Web Imager (KCWI) at high spectral and spatial resolution. map 10 to sample kinematic ionization properties individual star-forming regions. Using low resolution mode KCWI we oxygen abundance with identify 46 H II These regions have an average radius 4.0 pc, star formation rate $\sim1.3\times10^{-4}$ M$_\odot$ yr$^{-1}$, velocity dispersion $\sim$16 km s$^{-1}$. None appear be...
Abstract We present results from the Quasar hosts Unveiled by high Angular Resolution Techniques survey studying circumgalactic medium (CGM) observing rest-frame UV emission lines Ly α , C iv and He ii around two radio-loud quasars, 3C 9 ( z = 2.02) 4C 05.84 2.32), using Keck Cosmic Web Imager. detect large-scale nebulae both quasars with projected diameters ∼100 kpc, spatially resolved, embedded 15–30 kpc as well kinematically distinct at a physical separation of ∼15 quasars. Observations H...
Liger is an adaptive optics (AO) fed imager and integral field spectrograph (IFS) designed to take advantage of the Keck All-sky Precision Adaptive-optics (KAPA) upgrade I telescope. adapts design InfraRed Imaging Spectrograph (IRIS) for Thirty Meter Telescope (TMT) by implementing a new re-imaging optics. The performance critical as it sequentially feeds contains essential components such pupil wheel, filter viewing camera. We present structural analysis optical assembly including static,...
Optical SETI (Search for Extraterrestrial Intelligence) instruments that can explore the very fast time domain, especially with large sky coverage, offer an opportunity new discoveries complement multimessenger and domain astrophysics. The Panoramic experiment (PANOSETI) aims to observe optical transients nanosecond second duration over a wide field-of-view (∼2,500 sq.deg.) by using two assemblies of tens telescopes reject spurious signals coincidence detection. Three PANOSETI telescopes,...
The Panoramic Search for Extraterrestrial Intelligence (PANOSETI) experiment is designed to detect pulsed optical signals on nanosecond timescales. PANOSETI therefore sensitive Cherenkov radiation generated by extensive air showers, and can be used gamma-ray astronomy. Each telescope uses a 0.5 m Fresnel lens focus light onto 1024 pixel silicon photomultiplier camera that images 9.9$^\circ\times$9.9$^\circ$ square field of view. Recent detections PeV gamma-rays from extended sources in the...
We present a progress report on the development of new broadband mirror coatings that demonstrate ⪆ 80% reflectivities from 1020−5000Å. Four different coating recipes are presented as candidates for future far-ultraviolet (FUV) sensitive observatories. Three samples were first coated with aluminum (Al) and lithium fluoride (LiF) at NASA Goddard Space Flight Center (GSFC) using high-temperature physical vapor deposition (PVD) process. Two these then had an ultrathin (10−20 Å) protective coat...
PANOSETI (Pulsed All-Sky Near-infrared Optical Search for Extra Terrestrial Intelligence) is a dedicated SETI (Search Extraterrestrial observatory that being designed to observe 4,441 sq. deg. search nano- millisecond transient events. The experiment will have dual system has total of 90 identical optical 0.48 m telescopes each 99 square degree field view. two sites be separated by 1 km distance help eliminate false positives and register definitive signal. We discuss the overall mechanical...
The Panoramic SETI (Search for Extraterrestrial Intelligence) experiment (PANOSETI) aims to detect and quantify optical transients from nanosecond second precision over a large field-of-view ($\sim$4,450 square-degrees). To meet these challenging timing wide-field requirements, the PANOSETI will use two assemblies of $\sim$45 telescopes reject spurious signals by coincidence detection, each one comprising custom-made fast photon-counting hardware combined with ($f/1.32$) focusing optics....
We present results from the ``Quasar hosts Unveiled by high Angular Resolution Techniques" (QUART) survey studying Circumgalactic Medium (CGM) observing rest-frame UV emission lines Ly$\alpha$, C IV and He II around two radio-loud quasars, 3C 9 (z=2.02) 4C 05.84 (z=2.32), using Keck Cosmic Web Imager (KCWI). detect large-scale Ly$\alpha$ nebulae both quasars with projected diameters $\sim$ 100 kpc, spatially resolved, embedded 15-30 kpc as well kinematically distinct at a physical separation...
Measurements of oxygen abundance throughout galaxies provide insight to the formation histories and ongoing processes. Here we present a study gas phase in HII regions diffuse nearby starburst dwarf galaxy, IC 10. Using Keck Cosmic Web Imager (KCWI) at W.M. Observatory, map central region 10 from 3500-5500A. The auroral [OIII]4363A line is detected with high signal-to-noise 12 46 observed, allowing for direct measurement abundance, yielding median standard deviation...
Abstract Measurements of oxygen abundance throughout galaxies provide insight to the formation histories and ongoing processes. Here we present a study gas-phase in H ii regions diffuse gas nearby starburst dwarf galaxy, IC 10. Using Keck Cosmic Web Imager at W. M. Observatory, map central region 10 from 3500 5500 Å. The auroral [O III ] 4363 Å line is detected with high signal-to-noise ratio 12 46 II observed, allowing for direct measurement abundance, yielding median standard deviation...
We present the design for a far-UV integral field spectrograph astronomy enabled by two-axis digital micromirror arrays. Techniques used spectroscopy in Optical-IR bandpass either do not apply to due low material transmission, or have other UV-specific challenges. In order circumvent this limitation, we designed an all-reflective method of dynamically reformatting focal plane telescope with micro-opto-electro-mechanical systems (MOEMS). The Adaptive Micromirror Array Demonstration Experiment...
This paper presents the design and theory of operation for a semi-automated reflectivity chamber ultraviolet optimized optics. A graphical user interface designed in LabVIEW controls stages, interfaces with detector system, takes semi-autonomous measurements, monitors system case error. Samples an optical photodiode sit on optics plate mounted to rotation stage middle vacuum chamber. The rotates samples diode between incident reflected position measure absolute at wavelengths limited by...
Recent technological advances have opened up new instrument capabilities for ultraviolet (UV) astronomy. Of particular interest are advanced deposition processes that increased the performance of Lithium Fluoride (LiF) overcoated mirrors while mitigating procedures required their handling, raising reflectivity from ∼ 65% to greater than 80% in Lyman UV (λ > 1000 Å). Traditional magnesium fluride (MgF<sub>2</sub>) protected aluminum a truncated at 1150 Å, missing crucial...
Liger is a next-generation near-infrared imager and integral field spectrograph (IFS) planned for the W.M. Keck Observatory. designed to take advantage of improved adaptive optics (AO) from All-Sky Precision Adaptive Optics (KAPA) upgrade currently underway. operates at 0.84-2.45 µm with spectral resolving powers R∼4,000-10,000. makes use sequential design allowing simultaneous observations. There are two modes: lenslet high spatial sampling 14 31 mas, slicer 75 150 mas an expanded view. Two...
Liger is a next-generation near-infrared (810 - 2450 nm) integral field spectrograph (IFS) and imaging camera for the Keck Observatory adaptive optics (AO) system. will enable new science by providing enhanced capabilities, including higher spectral resolving power (R=4,000 – 10,000), access to shorter wavelengths (< 1000 nm), larger fields of view (13 arcsec x 7 arcsec) than any current or planned ground- space-based IFS The sequentially feeds an that makes use slicer assembly unit lenslet...
Liger is a next generation adaptive optics (AO) fed integral field spectrograph (IFS) and imager for the W. M. Keck Observatory. This new instrument being designed to take advantage of upgraded AO system provided by All-Sky Precision Adaptive-optics (KAPA). will provide higher spectral resolving power (R$\sim$4,000-10,000), wider wavelength coverage ($\sim$0.8-2.4 $\mu$m), larger fields view than any current IFS. We present design analysis custom-made dewar chamber characterizing...
We will present the status of next generation near-infrared (0.84 - 2.45 micron) imager and integral field spectrograph (IFS) instrument, Liger, that is being designed for W. M. Keck Observatory. The Liger IFS operates concurrently on-sky are optimized to sample All-sky Precision Adaptive optics (KAPA) system. design able offer new science capabilities by extending bluer wavelength coverage, larger views, range spectral resolving powers. discuss overall technical design, requirements,...