L. Javier Romualdez
A5017239361- Adaptive optics and wavefront sensing
- Aerospace Engineering and Energy Systems
- Spacecraft and Cryogenic Technologies
- Superconducting and THz Device Technology
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Advanced Thermodynamic Systems and Engines
- Inertial Sensor and Navigation
- Spacecraft Design and Technology
- Cryospheric studies and observations
- Radio Astronomy Observations and Technology
- Atmospheric Ozone and Climate
- Photocathodes and Microchannel Plates
- Infrared Target Detection Methodologies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Photoacoustic and Ultrasonic Imaging
- Optical measurement and interference techniques
- Spaceflight effects on biology
- COVID-19 diagnosis using AI
- Optical Systems and Laser Technology
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Advanced ceramic materials synthesis
- Planetary Science and Exploration
University of Toronto
2016-2024
Princeton University
2020-2021
California University of Pennsylvania
2020
Durham University
2018
Institute for Christian Studies
2016-2018
Carleton University
2011
We present integral field spectroscopy of galaxy cluster Abell 3827, using ALMA and VLT/MUSE. It reveals an unusual configuration strong gravitational lensing in the core, with at least seven lensed images a single background spiral galaxy. Lens modelling based on HST imaging had suggested that dark matter associated one cluster's central galaxies may be offset. The new spectroscopic data enable better subtraction foreground light, identification multiple images. inferred distribution is...
In April to May 2023, the superBIT telescope was lifted Earth's stratosphere by a helium-filled super-pressure balloon, acquire astronomical imaging from above (99.5% of) atmosphere. It launched New Zealand then, for 40 days, circumnavigated globe five times at latitude 50 degrees South. Attached were four 'DRS' (Data Recovery System) capsules containing 5 TB solid state data storage, plus GNSS receiver, Iridium transmitter, and parachute. Data copied these, two dropped over Argentina. They...
Balloon-borne astronomy offers an attractive option for experiments that require precise pointing and attitude stabilization, due to a large reduction in the atmospheric interference observed by ground-based systems as well low-cost short development time-scale compared space-borne systems. The Imaging Testbed (BIT) is instrument designed meet technological requirements of high-precision astronomical missions, precursor facility-class with capabilities similar Hubble Space Telescope....
We describe the cryogenic system being developed for Taurus: a super-pressure balloon-borne microwave polarimeter scheduled to fly in 2027. The Taurus consists of 660L liquid helium cryostat which achieves base temperature <100mK with help capillary-fed superfluid tank and closed cycle dilution refrigerator. main is supported fiberglass flexures encased two layers vapor-cooled shields allow make full use extended flight time offered by balloon platform. projected hold over 50 days while...
Abstract This paper presents optical night sky brightness measurements from the stratosphere using CCD images taken with Super-pressure Balloon-borne Imaging Telescope (SuperBIT). The data used for estimating backgrounds were obtained during three commissioning flights in 2016, 2018, and 2019 at altitudes ranging 28 to 34 km above sea level. For a valid comparison of mountain-top ground-based observatories (taken zenith on darkest moonless high Galactic ecliptic latitudes), stratospheric...
Balloon-borne astronomy is unique in that it allows for a level of image stability, resolution, and optical backgrounds are comparable to space-borne systems due greatly reduced atmospheric interference, but at fraction the cost over significantly development time-scale. Instruments operating within visible-to-near-UV bands ($300$ - $900$ um) can achieve theoretical diffraction limited resolution $0.01"$ from stratosphere ($35$ $40$ km altitude) without need extensive adaptive required by...
This paper presents a novel method for the modal system identification of large mechanical structure by combining results from simulations and physical measurements. Specifically, reconstruction mode shapes was accomplished comparing simulated measured amplitude ratios generated using Nyquist analysis. The methodology developed in this improves upon traditional techniques allowing statistically cross-referencing relatively few sensor measurements simple simulation model. used to identify...
We present a publicly-available toolkit of flight-proven hardware and software to retrieve 5 TB data or small physical samples from stratospheric balloon platform. Before launch, capsule is attached the balloon, rises with it. Upon remote command, released descends via parachute, continuously transmitting its location. Software predict trajectory can be used select safe but accessible landing site. dropped two such capsules SuperBIT telescope, in September 2019. The took ~37 minutes descend...
Balloon-borne astronomy offers an attractive option for experiments that require precise pointing and attitude stabilization, due to a large reduction in the atmospheric interference observed by ground-based systems as well low-cost short development time-scale compared space-borne systems. The Imaging Testbed (BIT) is instrument designed meet technological requirements of high precision astronomical missions precursor facility class with capabilities similar Hubble Space Telescope....
The BLAST Observatory is a proposed super-pressure balloon-borne polarimeter designed for future ultra- long duration balloon campaign from Wanaka, New Zealand. To maximize scientific output while staying within the stringent weight envelope, will feature new 1.8m off-axis optical system contained lightweight monocoque structure gondola. payload incorporate 300 L <sup>4</sup>He cryogenic receiver which cool 8,274 microwave kinetic inductance detectors (MKIDs) to 100mK through use of an...
At a fraction of the total cost an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% Earth’s atmosphere, offer attractive, competitive, and effective observational capabilities—namely, space-like seeing, transmission, backgrounds—which are well suited for modern astronomy cosmology. The Super-pressure Balloon-borne Imaging Telescope (SUPERBIT) is diffraction-limited, wide-field, 0.5 m telescope capable exploiting these observing conditions in order to...
In this work we describe upgrades to the Spider balloon-borne telescope in preparation for its second flight, currently planned December 2021. The instrument is optimized search a primordial B-mode polarization signature cosmic microwave background at degree angular scales. During first flight 2015, mapped ~10% of sky 95 and 150 GHz. payload Antarctic will incorporate three new 280 GHz receivers alongside refurbished 95- from Spider's flight. discuss design characterization these receivers,...
Taurus is a balloon-borne cosmic microwave background (CMB) experiment optimized to map the E-mode polarization and Galactic foregrounds at largest angular scales ($\ell$ $\lt$ 30) improve measurements of optical depth reionization ($\tau$). This will pave way for improved sum neutrino masses in combination with high-resolution CMB data while also testing $\Lambda CDM$ model on large providing high-frequency maps polarized dust community. These take advantage low-loading environment found...
The Super-pressure Balloon-borne Imaging Telescope (SuperBIT) is a near-diffraction-limited 0.5m telescope that launched via NASA's super-pressure balloon technology on April 16, 2023. SuperBIT achieved precise pointing control through the use of three nested frames in conjunction with an optical Fine Guidance System (FGS), resulting average image stability 0.055" over 300-second exposures. FGS includes tip-tilt fast-steering mirror corrects for jitter pair focal plane star cameras. In this...
Titania doped YSZ ceramic samples were subjected to calorimetric, thermal and microstructural analyses assess the value of titania as a dopant for use barrier coating in modern gas turbine engines. The primary objective addition was effectively stabilize tetragonal phase at operating temperatures while lowering conductivity. Powder blends with 5, 10, 15 wt% added standard 7YSZ powder sintered 1200°C 325hrs after plasma spraying. Basic physical properties related conductivity material such...
Abstract SuperBIT was a 0.5 m near-UV to near-infrared wide-field telescope that launched on NASA superpressure balloon into the stratosphere from New Zealand for 45-night flight. acquired multiband images of galaxy clusters study properties dark matter using weak gravitational lensing. We provide an overview instrument and its various subsystems. then present performance flight, including image stabilization system, optical power thermal system. successfully met instrument’s technical...
Spider is a balloon-borne instrument designed to map the cosmic microwave background at degree-angular scales in presence of Galactic foregrounds. has mapped large sky area Southern Hemisphere using more than 2000 transition-edge sensors (TESs) during two NASA Long Duration Balloon flights above Antarctic continent. During its first flight January 2015, was observed 95- and 150-GHz frequency bands, setting constraints on B-mode signature primordial gravitational waves. Its second 2022–2023...
Balloon-borne astronomy is a unique tool that allows for level of image stability and significantly reduced atmospheric interference without the often prohibitive cost long development time-scale are characteristic space-borne facility-class instruments. The Super-pressure Imaging Telescope (SuperBIT) wide-field imager designed to provide 0.02" over 0.5 degree field-of-view deep exposures within visible-to-near-UV (300-900 um). As such, SuperBIT suitable platform wide range balloon-borne...