A5055413248- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Superconducting and THz Device Technology
- Astronomical Observations and Instrumentation
- Space Satellite Systems and Control
- Optical Wireless Communication Technologies
- Calibration and Measurement Techniques
- Photonic and Optical Devices
- Neural Networks and Reservoir Computing
- Planetary Science and Exploration
- Advanced Fiber Optic Sensors
- Gamma-ray bursts and supernovae
- Advanced Measurement and Metrology Techniques
- Astro and Planetary Science
- Spacecraft and Cryogenic Technologies
- Glass properties and applications
- Optical Network Technologies
- Silicon Nanostructures and Photoluminescence
- Advanced optical system design
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- Advanced Thermodynamic Systems and Engines
- Ion-surface interactions and analysis
- Earth Systems and Cosmic Evolution
Australian National University
2005-2024
ETH Zurich
2024
National University College
2022
New Generation University College
2022
The Large Interferometer For Exoplanets (LIFE) is a proposed space mission that enables the spectral characterization of thermal emission exoplanets in solar neighborhood. designed to search for global atmospheric biosignatures on dozens temperate terrestrial and it will naturally investigate diversity other worlds. Here, we review status concept, discuss key parameters, outline trade-offs related mission's architecture. In preparation an upcoming concept study, define baseline based...
Extended x-ray absorption fine structure (EXAFS) measurements have been used to characterize the ion-irradiation-induced crystalline-to-amorphous phase transformation in Ge nanocrystals. The atomic-scale of nanocrystals a silica matrix is first shown deviate from that bulk crystalline material with an increase both Gaussian and non-Gaussian forms structural disorder. magnitude disorder bond-length distribution comparable relaxed amorphous Ge. amorphization such then demonstrated at ion dose...
Abstract Gaia DR2 provides an unprecedented sample of stars with full 6D phase-space measurements, creating the need for a self-consistent means discovering and characterising overdensities known as moving groups or associations. Here we present Chronostar, new Bayesian analysis tool that meets this need. Chronostar uses Expectation-Maximisation algorithm to remove circular dependency between association membership lists fits their distributions, making it possible discover unknown...
Aims: Optical interferometry from space for the purpose of detecting and characterising exoplanets is seeing a revival, specifically missions such as proposed Large Interferometer For Exoplanets (LIFE). A default assumption since design studies Darwin TPF-I has been that Emma X-array configuration optimal architecture this goal. Here, we examine whether new advances in field nulling interferometry, concept kernel nulling, challenge assumption. Methods: We develop tool designed to derive...
<i>Context</i> — The Large Interferometer for Exoplanets (LIFE) is a proposed space mission to characterise the atmosphere of terrestrial exoplanets, which planned operate in mid-infrared wavelength region from 6μm 16μm. A key requirement needed study feasibility this demonstrate broadband nulling at cryogenic temperatures (15K), flux levels comparable astronomical sources that LIFE will detect. Nulling Cryogenic Experiment (NICE) technology demonstrator built fulfil purpose....
Space interferometry is the inevitable endpoint of high angular resolution astrophysics, and a key technology that can be leveraged to analyse exoplanet formation atmospheres with exceptional detail. However, anticipated cost large missions such as Darwin TPF-I, inadequate readiness levels have resulted in limited developments since late 2000s. Here, we present feasibility study into small scale flying interferometric array Low Earth Orbit, will aim prove technical concepts involved space...
The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization distances from the solar system far greater than thermally equilibrated terrestrial exoplanets, offering observational opportunities for unique insights into origin secondary atmospheres and near surface conditions prebiotic environments. Large Interferometer For Exoplanets (LIFE) mission will employ a space-based mid-infrared nulling...
(Abridged) Context: In the previous paper in this series, we identified that a pentagonal arrangement of five telescopes, using kernel-nulling beam combiner, shows notable advantages for some important performance metrics space-based mid-infrared nulling interferometer over several other considered configurations detection Earth-like exoplanets around solar-type stars. Aims: We aim to produce physical implementation combiner such configuration, as well discussion systematic and stochastic...
In the past few years, there has been a resurgence in studies of space-based optical/infrared interferometry, particularly with vision to use technique discover and characterize temperate Earth-like exoplanets around solar analogs. One key technological leaps needed make such mission feasible is demonstrating that formation flying precision at level for interferometry possible. Here, we present Pyxis, ground-based demonstrator future small satellite aim demonstrate metrology interferometry....
Statistical studies of exoplanets and the properties their host stars have been critical to informing models planet formation. Numerous trends arisen in particular from rich Kepler dataset, including that are more likely be found around with a high metallicity presence "gap" distribution planetary radii at 1.9$R_\oplus$. Here we present new analysis on field, using APOGEE spectroscopic survey build calibration based Gaia, 2MASS Stromgren photometry. This calibration, along masses derived...
Dome seeing is an often overlooked avenue for improvement a telescope. Because most existing telescope domes have not been characterized turbulence, there opportunity to improve the overall by minimizing dome contribution, thereby optimizing scientific productivity and operations. A turbulence sensor has recorded data in Anglo-Australian Telescope (AAT) over past year. The instrument consists of collimated laser beam that propagates (and double passes) between AAT’s primary mirror box flat...
Space interferometers could, in principle, exploit the relatively stable space environment and ease of baseline reconfiguration to collect measurements beyond limitations ground-based interferometers. In particular, a two-element interferometer could provide excellent uv-plane coverage over few tens low-Earth orbits. One challenges for free-flying is controlling optical path distance with sub-wavelength accuracies despite collectors flying up hundreds meters apart. This work considers two...
(Abridged) Context: In the previous paper in this series, we identified that a pentagonal arrangement of five telescopes, using kernel-nulling beam combiner, shows notable advantages for some important performance metrics space-based mid-infrared nulling interferometer over several other considered configurations detection Earth-like exoplanets around solar-type stars. Aims: We aim to produce physical implementation combiner such configuration, as well discussion systematic and stochastic...
Beam combiners are important components of an optical/infrared astrophysical interferometer, with many variants as to how optimally combine two or more beams light fringe-track and obtain the complex fringe visibility. One such method is use integrated optics chip that can instantaneously provide measurement visibility without temporal spatial modulation optical path. Current asymmetric planar designs complex, resulting in a throughput penalty, so here we present developments into three...
Space interferometers could, in principle, exploit the relatively stable space environment and ease of baseline reconfiguration to collect measurements beyond limitations ground-based interferometers. In particular, a two-element interferometer could provide excellent uv-plane coverage over few tens low Earth orbits. One challenges for free-flying is controlling optical path distance with subwavelength accuracies despite collectors flying up hundreds meters apart. We consider two approaches:...
In recent years, there has been a renewed interest in technology development for space-based optical and infrared interferometry. One such pathfinder is <i>Pyxis</i>, set of three autonomous robotic platforms designed to operate the carpark Mt Stromlo Observatory, Canberra, where it will simulate formation-flying while performing this paper, we provide an update on interferometer, detailing initial results control subsystems. We also share our future plans begin space qualification...
The Large Interferometer For Exoplanets (LIFE) is a proposed space-based mid-infrared nulling interferometer featuring an array of formation-flying collectors and central beam combiner. Its primary objective the direct detection dozens temperate, terrestrial exoplanets investigation their atmospheres to understand composition identify potential biosignatures. To get realistic performance estimate LIFE derive technical requirements, comprehensive understanding all major noise sources...
Optical interferometry from space is arguably the most exciting prospect for high angular resolution astrophysics; including analysis of exoplanet atmospheres. This was highlighted in recent ESA Voyage 2050 plan, which pointed out potential this technology, but also indicated critical need technological demonstrators. Here we present Pyxis interferometer; a ground-based pathfinder CubeSat interferometer, currently being built at Mt Stromlo Observatory. We outline its and scientific as only...
Space interferometry is the inevitable endpoint of high angular resolution astrophysics, and a key technology that can be leveraged to analyse exoplanet formation atmospheres with exceptional detail. Here, we present feasibility study into small scale flying interferometric array, in Low Earth Orbit, will aim prove technical concepts involved space while still making unique astrophysical measurements. We detail design mission, as well orbital simulations show array should stable enough...
A space interferometer could reach a sensitivity and angular resolution which is unattainable on Earth due to the distortion absorption of atmosphere. It would enable many unique science cases, including direct imaging characterisation temperate terrestrial exoplanets. This ambitious vision relies formation flying individual spacecrafts, demonstration precision metrology measuring positions in better than 1mm at least 2 dimensions, velocities range nm/s. These significant technical...
Two major contributors to the overall seeing that degrades astronomical images are turbulence from atmosphere and within telescope dome structure. Dome generally contributes less than 1 arcsec seeing. However, most existing domes have not been characterized for seeing; there is an opportunity significantly improve by optimizing An instrument measures a proxy was installed at Anglo-Australian Telescope (AAT) Siding Spring Observatory in Australia. The based on similar 'dome monitor' built...
The <i>Pyxis </i>interferometer is a ground-based pathfinder for an optical space interferometer being built at Mt Stromlo Observatory. In this second paper, we discuss the system breakdown of and its mechanical design. We outline interferometer's three robotic platforms, with two telescopic collectors one central beam combiner. Each collector utilises full aluminium, diamond-turned telescope, designed to remove thermal distortions future applications. also explain chosen control how it will...
In the past few years, there has been a resurgence in studies towards space-based optical/infrared interferometry, particularly with vision to use technique discover and characterise temperate Earth-like exoplanets around solar analogues. One of key technological leaps needed make such mission feasible is demonstrating that formation flying precision at level for interferometry possible. Here, we present $\textit{Pyxis}$, ground-based demonstrator future small satellite aim demonstrate...
The European Space Agency (ESA) launched a mission, named Gaia, that recently released its first catalogue of data.In this essay, I detail why Gaia is important and how it revolutionary to the field astrometry (the study position motions celestial objects).I also describe various techniques for finding exoplanets no technique, with exception astrometry, can find true mass an exoplanet.Finally, explain may be one missions detect astrometric technique and, by extension, distribution exoplanets.