A5054971322- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Astronomy and Astrophysical Research
- CCD and CMOS Imaging Sensors
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Infrared Target Detection Methodologies
- Calibration and Measurement Techniques
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Advanced Vision and Imaging
- Satellite Image Processing and Photogrammetry
- Geophysics and Sensor Technology
- Advanced Measurement and Detection Methods
- Economic and Technological Innovation
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Advanced Optical Sensing Technologies
- Pulsars and Gravitational Waves Research
- Photocathodes and Microchannel Plates
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Ocular and Laser Science Research
SLAC National Accelerator Laboratory
2020-2024
Kavli Institute for Particle Astrophysics and Cosmology
2020-2023
Stanford University
2023
University of California, Davis
2015-2021
Linac Coherent Light Source
2020
Mitchell Institute
2009
Texas A&M University
2009
The Ohio State University
2009
(Abridged) We describe here the most ambitious survey currently planned in optical, Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST have unique capability faint time domain. The design is driven four main themes: probing dark energy matter, taking an inventory Solar System, exploring transient optical sky, mapping Milky Way. wide-field ground-based system sited at Cerro Pach\'{o}n northern Chile. telescope 8.4 m...
Abstract We report studies on the mitigation of optical effects bright low-Earth-orbit (LEO) satellites Vera C. Rubin Observatory and its Legacy Survey Space Time (LSST). These include options for pointing telescope to avoid satellites, laboratory investigations trails LSST camera sensors, algorithms correcting image artifacts caused by trails, experiments darkening SpaceX Starlink ground-based follow-up observations. The original v0.9 are g ∼ 4.5 mag, initial experiment “DarkSat” is 6.1...
In May 2019 SpaceX launched its first batch of 60 Starlink communication satellites, which surprised astronomers and laypeople with their appearance in the night sky. Astronomers have only now, a little over year later, accumulated enough observations constellation satellites like those being by OneWeb, run computer simulations likely impact when fully deployed, to thoroughly understand magnitude complexity problem. This research informed discussion at Satellite Constellations 1 (SATCON1)...
Reduction of images and science analysis from ground-based telescopes such as the LSST requires detailed knowledge PSF image, which includes components attributable to instrument well atmosphere. Because atmospheric component is constantly changing, typically extracted each image by measuring size shape star across CCD, then building a fitting function over focal plane used model for extended sources galaxies. Since stars in CCD field have range brightnesses, accurate point varying...
We describe a camera beam simulator for the LSST which is capable of illuminating 60mm field at f/1.2 with realistic astronomical scenes, enabling studies CCD astrometric and photometric performance. The goal to fully simulate observing, in order characterize charge transport other features thick depleted CCDs probe low level systematics under conditions. automated system simulates centrally obscured sky including spectral shape night sky. doubly telecentric design uses nearly unit...
Abstract The Vera C. Rubin Observatory’s LSST Camera (LSSTCam) pixel response has been characterized using laboratory measurements with a grid of artificial stars. We quantify the contributions to photometry, centroid, point-spread function size, and shape measurement errors due small anomalies in LSSTCam CCDs. main sources those are quantum efficiency variations area induced by amplifier segmentation boundaries “tree-rings”—circular silicon doping concentration. This study stars projected...
A dedicated simulator, Poisson_CCD, has been constructed which models astronomical CCDs by solving Poisson’s equation numerically and simulating charge transport within the CCD. The potentials free carrier densities CCD are self-consistently solved for, giving realistic results for distribution storage wells. simulator used to model that being construct LSST digital camera. output validated comparing its predictions with several different types of measurements, including astrometric shifts,...
We characterize the astrometric distortion at edges of thick, fully-depleted CCDs in lab using a bench-top simulation LSST observing. By illuminating an array forty thousand pinholes (30mu m diameter) object plane f/1.2 optical reimager, thousands PSFs can be imaged over 4Kx4K pixel CCD. Each high purity silicon pixel, 10mu square by 100mu deep, then individually characterized through series sub-pixel dithers X/Y plane. The unique character [response, position, shape] each as function flux,...
The 3.2 gigapixel LSST camera, an array of 189 thick fully-depleted CCDs, will repeatedly image the southern sky and accomplish a wide variety science goals. However, its trove tens billions object images implies stringent requirements on systematic biases imprinted during shift-and-stare CCD observation. In order to correct for these which, without correction, violate weak lensing precision, we investigate systematics using both simulations charge transport as well with unique bench-top...
The LSST Camera for the Vera C. Rubin Observatory has been constructed at SLAC National Accelerator Laboratory. covers a 3.5-degree field of view with 3.2 gigapixels. goal survey is to provide well-understood astronomical source catalog community. Camera's focal plane populated by 189 sensors on science that are combination E2V CCD250 and ITL STA3800 deep-depletion, back-illuminated devices, accompanying eight guide sensors, four wavefront sensors. Nine grouped as "Raft" three identical...
We explore the weak lensing E- and B-mode shear signals of a field galaxy clusters using both large scale structure N-body simulations multi-color Suprime-cam & Hubble Space Telescope observations. Using ray-traced observed shears along with photometric redshift catalogs, we generate mass maps foreground overdensities by optimally filtering tangential that they induce on background galaxies. then develop test method to approximate as superposition NFW-like halos locating these determining...
Electro-optical testing and characterization of the Vera C. Rubin Observatory Legacy Survey Space Time (LSST) Camera focal plane, consisting 205 charge-coupled devices (CCDs) arranged into 21 stand-alone Raft Tower Modules (RTMs) 4 Corner (CRTMs), is currently being performed at SLAC National Accelerator Laboratory. Testing camera sensors using a set custom-built optical projectors, designed to illuminate full plane or specific regions with series light illumination patterns: crosstalk...
The Vera C. Rubin Observatory's LSST Camera (LSSTCam) pixel response has been characterized using laboratory measurements with a grid of artificial stars. We quantify the contributions to photometry, centroid, point-spread function size, and shape measurement errors due small anomalies in LSSTCam CCDs. main sources those are quantum efficiency variations area induced by amplifier segmentation boundaries "tree-rings" - circular silicon doping concentration. This study stars projected on...
We are conducting a long-term photometric survey of the nearby galaxy M33 to discover Cepheids, eclipsing binaries, and long-period variables. The dataset combines previously-obtained optical images from DIRECT project with new observations acquired at WIYN 3.5m telescope. entire data set spans over 7 years excellent synoptic coverage which will enable discovery characterization stars displaying variability wide range timescales (days, weeks, months, years). In this preliminary work we show...