J. Bryce Kalmbach
A5042922015- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Planetary Science and Exploration
- Geomagnetism and Paleomagnetism Studies
- Scientific Research and Discoveries
- Granular flow and fluidized beds
- Optical Systems and Laser Technology
- Astrophysics and Cosmic Phenomena
- Remote Sensing and LiDAR Applications
- Big Data Technologies and Applications
- Computational Physics and Python Applications
- Hydraulic Fracturing and Reservoir Analysis
- Spectroscopy and Chemometric Analyses
- Isotope Analysis in Ecology
- Satellite Image Processing and Photogrammetry
- Geographic Information Systems Studies
- Robotics and Sensor-Based Localization
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- Tree Root and Stability Studies
City University of Seattle
2020-2024
University of Washington
2017-2024
Drexel University
2018
Large Synoptic Survey Telescope Corporation
2015
University of California System
2009
Abstract The Astropy Project supports and fosters the development of open-source openly developed Python packages that provide commonly needed functionality to astronomical community. A key element is core package astropy , which serves as foundation for more specialized projects packages. In this article, we summarize features in recent major release, version 5.0, updates on Project. We then discuss supporting a broader ecosystem interoperable packages, including connections with several...
The Large Synoptic Survey Telescope (LSST) is a large-aperture, wide-field, ground-based survey system that will image the sky in six optical bands from 320 to 1050 nm, uniformly covering approximately $18,000$deg$^2$ of over 800 times. LSST currently under construction on Cerro Pachón Chile, and expected enter operations 2022. Once operational, explore wide range astrophysical questions, discovering "killer" asteroids examining nature Dark Energy. generate average 15 TB data per night,...
Abstract We describe the simulated sky survey underlying second data challenge (DC2) carried out in preparation for analysis of Vera C. Rubin Observatory Legacy Survey Space and Time (LSST) by LSST Dark Energy Science Collaboration (LSST DESC). Significant connections across multiple science domains will be a hallmark LSST; DC2 program represents unique modeling effort that stresses this interconnectivity way has not been attempted before. This encompasses full end-to-end approach: starting...
Abstract Many scientific investigations of photometric galaxy surveys require redshift estimates, whose uncertainty properties are best encapsulated by (photo-z) posterior probability density functions (PDFs). A plethora photo-z PDF estimation methodologies abound, producing discrepant results with no consensus on a preferred approach. We present the comprehensive experiment comparing twelve algorithms applied to mock data produced forLarge Synoptic Survey Telescope The Rubin Observatory...
Abstract The DECam Ecliptic Exploration Project (DEEP) is a deep survey of the trans-Neptunian solar system being carried out on 4 m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile using Dark Energy Camera (DECam). By shift-and-stack technique to achieve mean limiting magnitude r ∼ 26.2, DEEP achieves an unprecedented combination area and depth, enabling quantitative leaps forward our understanding Kuiper Belt populations. This work reports results from analysis 20, 3...
Abstract We present the first set of trans-Neptunian objects (TNOs) observed on multiple nights in data taken from DECam Ecliptic Exploration Project. Of these 110 TNOs, 105 do not coincide with previously known TNOs and appear to be new discoveries. Each individual detection for our resulted a digital tracking search at TNO rates motion, using two-to-four-hour exposure sets, detections were subsequently linked across observing seasons. This procedure allows us find magnitudes m VR ≈ 26. The...
Abstract Evaluating the accuracy and calibration of redshift posteriors produced by photometric (photo- z ) estimators is vital for enabling precision cosmology extragalactic astrophysics with modern wide-field surveys. photo- on a per-galaxy basis difficult, however, as real galaxies have true but not posterior. We introduce PZFlow, Python package probabilistic forward modeling galaxy catalogs normalizing flows. For simulated there natural notion “true” that can be used validation. use...
Abstract We present a detailed study of the observational biases DECam Ecliptic Exploration Project’s B1 data release and survey simulation software that enables direct statistical comparisons between models our data. inject synthetic population objects into images, then subsequently recover them in same processing as real detections. This us to characterize survey’s completeness function apparent magnitudes on-sky rates motion. statistically optimal functional form for magnitude, develop...
The Vera C. Rubin Observatory will, over a period of 10 years, repeatedly survey the southern sky. To ensure that images generated by meet quality requirements for precision science, observatory will use an Active Optics System (AOS) to correct alignment and mirror surface perturbations introduced gravity temperature gradients in optical system. accomplish this out-of-focus from sensors located at edge focal plane learn wavefront. We have designed integrated deep learning model wavefront...
The use of high-quality simulated sky catalogs is essential for the success cosmological surveys. have diverse applications, such as investigating signatures fundamental physics in observables, understanding effect systematic uncertainties on measured signals and testing mitigation strategies reducing these uncertainties, aiding analysis pipeline development testing, survey strategy optimization. list applications growing with improvements quality details that they can provide. Given...
Abstract Accurate photometric redshift (photo- z ) estimates are essential to the cosmological science goals of Vera C. Rubin Observatory Legacy Survey Space and Time (LSST). In this work, we use simulated photometry for mock galaxy catalogs explore how LSST photo- can be improved by addition near-infrared (NIR) and/or ultraviolet ( UV from Euclid, Wide-Field InfrarRed Telescope (WFIRST), Cosmological Advanced Optical Research (CASTOR) space telescopes. Generally, find that deeper optical...
This paper presents a new optical imaging survey of four deep drilling fields (DDFs), two Galactic and extragalactic, with the Dark Energy Camera (DECam) on 4 meter Blanco telescope at Cerro Tololo Inter-American Observatory (CTIO). During first year observations in 2021, $>$4000 images covering 21 square degrees (7 DECam pointings), $\sim$40 epochs (nights) per field 5 to 6 night filter $g$, $r$, $i$, and/or $z$, have become publicly available (the proprietary period for this program is...
Abstract Understanding the formation and evolution of ring galaxies, which possess an atypical ring-like structure, is crucial for advancing knowledge black holes galaxy dynamics. However, current catalogs galaxies are limited, as manual analysis takes months to accumulate appreciable sample rings. This paper presents a convolutional neural network (CNN) identify from unclassified samples. A CNN was trained on 100,000 simulated transfer learned onto real applied previously data set generate...
ABSTRACT We report a study exploring how the use of deep neural networks with astronomical Big Data may help us find and uncover new insights into underlying phenomena: through our experiments towards unsupervised knowledge extraction from we serendipitously found that convolutional autoencoders tend to reject telluric lines in stellar spectra. With further experiments, only when spectra are barycentric frame does network automatically identify statistical independence between two...
Trans-Neptunian Objects (TNOs) provide a window into the history of Solar System, but they can be challenging to observe due their distance from Sun and relatively low brightness. Here we report detection 75 moving objects that could not link any other known objects, faintest which has VR magnitude $25.02 \pm 0.93$ using KBMOD platform. We recover an additional 24 sources with previously-known orbits. place constraints on barycentric distance, inclination, longitude ascending node these...
We present "Tracklet-less Heliocentric Orbit Recovery" (THOR), an algorithm for linking of observations Solar System objects across multiple epochs that does not require intra-night tracklets or a predefined cadence within search window. By sparsely covering regions interest in the phase space with "test orbits", transforming nearby over few nights into co-rotating frame test orbit at each epoch, and then performing generalized Hough transform on transformed detections followed by...
We measure stability of two-dimensional granular mixtures in a rotating drum and relate grain configurations to stability. use two types grains which differ both size shape, with the larger reaching average angle before an avalanche. In our mixtures, smaller cluster near center drum, while remain outer edge, pattern suggesting that rather than avalanche determines segregation behavior. One consequence is heavily influence heap. find maximum non-linear function composition, changing...
We introduce a new computational technique for searching faint moving sources in astronomical images. Starting from maximum likelihood estimate the probability of detection source within series images, we develop massively parallel algorithm through candidate asteroid trajectories that utilizes Graphics Processing Units (GPU). This can search over 10^10 possible stacks order 10-15 4K x images under minute using single consumer grade GPU. apply this to data 2015 campaign High Cadence...
Abstract Measuring the physical properties of galaxies such as redshift frequently requires use spectral energy distributions (SEDs). SED template sets are, however, often small in number and cover limited portions photometric color space. Here we present a new method to estimate SEDs function from training set SEDs. We first mathematical background behind technique before demonstrating our ability reconstruct spectra based upon colors then compare results other common interpolation...
In preparation for cosmological analyses of the Vera C. Rubin Observatory Legacy Survey Space and Time (LSST), LSST Dark Energy Science Collaboration (LSST DESC) has created a 300 deg$^2$ simulated survey as part an effort called Data Challenge 2 (DC2). The DC2 sky survey, in six optical bands with observations following reference observing cadence, was processed Pipelines (19.0.0). this Note, we describe public data release resulting object catalogs coadded images five years along...
Evaluating the accuracy and calibration of redshift posteriors produced by photometric (photo-z) estimators is vital for enabling precision cosmology extragalactic astrophysics with modern wide-field surveys. photo-z on a per-galaxy basis difficult, however, as real galaxies have true but not posterior. We introduce PZFlow, Python package probabilistic forward modeling galaxy catalogs normalizing flows. For simulated there natural notion "true" that can be used validation. use PZFlow to...
We measure stability of two-dimensional granular mixtures in a rotating drum and relate grain configurations to stability. For our system, the smaller but smoother grains cluster near center drum, while larger, rougher remain outer edge. One consequence size segregation is that heavily influence heap. find maximum angle non-linear function composition, changing particularly rapidly when small are first added homogeneous pile large grains. conclude configuration within central portion heap...