Recent Talks

Breakthrough Starshot is an initiative by the Breakthrough Foundation to prove ultra-fast ultra-light nanospacecraft can be launched by laser radiation pressure to nearby stars, and will lay the foundations for a first launch to Alpha Centauri within the next generation. Designs for a 0.2c Alpha Centauri mission minimize beam director capital cost by accelerating a ~4 m, several gram diameter sailcraft for ~10 min. A number of hard engineering challenges remain to be solved before these missions can become a reality: Large coherent laser arrays are required. No consensus has been reached on the most suitable sail geometry for stable flight, “beam-riding”. The sail itself requires major advances in materials science and photonic design to produce materials with the required absorptance, emittance, reflectance, areal density and operating temperature. Along the way, the project will enable increasingly fast outer solar system and interstellar precursor missions. Breakthrough Starshot will pave the way for multi-lightyear pipelines of sailcraft that fly past each target star every few weeks. Beams such as Starshot will produce an extremely observable transient feature of Earth and therefore could be an observable of extraterrestrial advanced civilizations.

El coste de los mayores telescopios actualmente en construcción es tal que la extrapolación de estos diseños a tamaños superiores a ~50 metros de diámetro parece inviable. Futuros telescopios gigantes deberán de construirse siguiendo modelos nuevos, algunos ya propuestos, otros aún en fase de desarrollo.

We are developing and will commission a space debris and satellite imaging system in New Zealand to improve image resolution of Earth orbiting objects. Our simplified, low-cost approach is based on restricting possible regions where orbiting satellites and large space debris objects pass through the Galactic plane, where they can be detected within a background of natural stars. We will use a modular, wide-field adaptive optics (AO) system to estimate the spatially variant point spread function (SVPSF) using multiple natural guide stars (NGSs) to compensate for atmospheric turbulence over a wide field-of-view (FoV). To achieve this, our custom designed geometric wavefront sensor will provide estimates of phase perturbations from three or more isoplanatic patches. A combination of closed- and open-loop adaptive optics is employed. The closed-loop system will use a bright NGS for low-order aberration reduction using a Shack Hartmann wavefront sensor for correcting the optical path using a tip/tilt mirror system in real-time. Our open-loop system will estimate wavefronts from three of more natural stars and use atmospheric tomography to determine the SVPSF, off-line. From the SVPSF estimate, deconvolution from wavefront sensing is used to remove high-order aberrations fast moving target objects that will be imaged using a separate detector, synchronised with our AO cameras. A model for this hybrid AO system is described in this talk and its implementation will provide a platform to test novel methods for system refinement.

I will provide highlights of work at the Space Telescope Science Institute (STScI), which provides science and operations support for NASA's space missions, delivers added value to data archives, and engages the public in the corresponding scientific results. We are preparing for continuing operations of the Hubble Space Telescope through 2025, looking forward to the launch of the James Webb Space Telescope, and contributing to the development of the Wide Field Infrared Survey Telescope. Staff at STScI are also advancing technology and scientific concepts for future flagship space missions.

Emerging flux regions (EFRs) are seen as magnetic concentrations in the photosphere of the Sun. From a theoretical point of view, the EFRs are formed in the convection zone and then emerge because of magnetic buoyancy (Parker instability) to the solar surface. During the formation process of EFRs, merging and cancellation of different polarities occur, leading to various configurations of the magnetic field. Often, EFRs are visible in the chromosphere in form of magnetic loops loaded with plasma, which are often called “cool loops” when seen in the chromosphere along with dark fibrils and they can reach up to the corona. Nowadays, we refer to them as an arch filament system (AFS) which connects two different polarities.  The AFSs are commonly observed in several chromospheric spectral lines. A suitable spectral line to investigate chromospheric features and particularly AFSs is the He I 10830 Å triplet. The new generation of solar telescopes and instruments such EST and DKIST, will allow us to record very high spectral, spatial, and temporal resolution observations necessary to investigate the dynamics, magnetic field, and characteristics of AFSs. These observations will help us to answer many open questions related to flux emergence such: (1) What are the observational consequences of the emerging flux? (2) How do EFRs evolve with time in the different layers of the solar atmosphere and how are these layers linked? (3) Is it possible to measure the height difference between the photosphere and the chromosphere connected by the legs of the AFSs?

A major goal for NASA's human spaceflight program is to send astronauts to the Moon and beyond in the coming decades. The first missions would focus on exploration of the Moon with the intent of developing the technologies and capabilities to then proceed on to Mars.  

However, there are many objects that show promise as future destinations beyond the Moon, which do not require the extensive mission capabilities or durations required for Mars exploration. These objects are known as Near-Earth Objects (NEOs) and would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration and serve as stepping stones for NASA’s efforts to reach Mars.  A subset of these objects has been identified within the ongoing investigation of the NASA Near-Earth Object Human Space Flight Accessible Targets Study (NHATS).

Information obtained from a human investigation of a NEO, together with ground-based observations and prior spacecraft investigations of asteroids and comets (e.g., Hayabusa2 and OSIRIS-REx), will provide a real measure of ground truth to data obtained from terrestrial meteorite collections.  In addition, robotic precursor and human exploration missions to NEOs would allow NASA and its international partners to gain operational experience in performing complex tasks (e.g., sample collection, deployment of payloads, retrieval of payloads, etc.) with crew, robots, and spacecraft under microgravity conditions at or near the surface of a small body.  This would provide an important synergy between the worldwide Science and Exploration communities, which will be crucial for development of future international deep space exploration architectures and has potential benefits for future exploration of destinations beyond the Earth-Moon system (e.g., Mars).

The number of photons received allows radio astronomers to resolve the
Universe on timescales of nanoseconds. This has been demonstrated over
decades by observations of giant pulses from the Crab Pulsar, why more
recently, it has led to the establishment of the  new research field of
Fast Radio Bursts. The latter were initially discovered in archival data but are now
established as a population of radio sources at cosmological distances.
While their origin still remains a mystery, they promise to become powerful
cosmological tools. This talk will briefly review time domain astronomy in
the radio regime, describe some of the latest FRB results, and will also address
the challenges. These range from dealing with large amounts of raw data
(PB to EB) that need to be processed in real-time with machine learning methods,
to delivering reliable triggers for multi-wavelength follow-up at optical and higher
frequencies.

Astrophysical masers are among of the best tools in studying star
formation processes, especially in massive star-forming regions where
star formation cores are deeply embedded in a complex gaseous
environment.  In this talk, I will give examples of such studies where
physical conditions (e.g. magnetic fields) as well as kinematics of the
regions can be derived from.  I will also highlight time-domain studies of
masers which help us to understand not only the physics and dynamics
of the regions but also maser physics itself.  At the end of my talk,
I will briefly present the latest development of radio astronomy research
in Thailand including the new 40-m Thai National Radio Telescope (TNRT)
and its future key science.

We are living in a golden era for testing gravitational physics with precision experiments. This talk will present new results using a variety of tests with radio astronomy, ranging from binary pulsars to imaging black holes in the centre of galaxies. These results will be placed in context of other ongoing experiments, such as detecting gravitational wave with ground-based detectors or pulsar timing arrays, before giving an outlook into the future.

The dust component of active galactic nuclei (AGN) produces a broad infrared spectral energy distribution (SED), whose power and shape depends on the fraction of the source absorbed, and the geometry of the absorber respectively. This emitting region is expected to be concentrated within the inner ∼5 pc of the AGN which makes almost impossible to image it with the current instruments. The study of the infrared SED by comparison between infrared AGN spectra and predicted models is one of the few ways to infer the properties of the AGN dust. We explore a set of six dusty models of AGN with available SEDs, namely Fritz et al. (2006), Nenkova et al. (2008B), Hoenig & Kishimoto (2010), Siebenmorgen et al. (2015), Stalevski et al. (2016), and Hoenig & Kishimoto (2017). They cover a wide range of morphologies, dust distributions, and compositions.

We explore the discrimination among models and parameter restriction using synthetic spectra (Gonzalez-Martin et al. 2019A), and perform spectral fitting of a sample of 110 AGN with Spitzer/IRS drawn from the Swift/BAT survey (Gonzalez-Martin et al. 2019B). Our conclusion is that most of these models can be discriminated using only mid-infrared spectroscopy as long as the host galaxy contribution is less than 50%. The best model describing the sample is the clumpy disk-wind model by Hoenig & Kishimoto (2017). However, large residuals are shown irrespective of the model used, indicating that AGN dust is more complex than models. We found that the parameter space covered by models is not completely adequate. This talk will give tips for observers and modelers to actually answer the question: how is the dust arrange in AGN? This question will be one of the main subjects of future research using JWST in the AGN field.