Exploring high contrast limitations for image slicer based integral field spectrographs
Proceedings of SPIE - The International Society for Optical Engineering 7015 (2008)
Abstract:
Current simulation and experimental investigatory work is going on into the performance of slicer and lenslet IFS designs. The aim of this work is to determine which technology holds the best promise for achieving the highest contrasts with EPICS on the E-ELT. Results from Spectral Deconvolution methods for high contrast detections are presented, both on sky images from AB Dor C observations using SINFONI on the VLT and improvements to the algorithms made through use of EPICS simulation data. Using these simulations, only containing photon and speckle noise, we have been able to detect simulated planets down to a contrast of 1010 located less than 1" from the parent star. The effects of spectral resolution and wavelength range on high contrast observations are discussed. Shortening the wavelength range increases the inner working angle. It is seen that an outer working angle is also reached that decreases with spectral resolution. The limit on the inner working angle can be overcome partly by increasing the wavelength range of the instrument although another inner working angle limit will be reached if a coronagraph is used. The limit of the outer working angle can also be overcome by increasing the spectral resolution of the instrument or possibly by making an IFS that produces an output with a constant spectral resolution, R,instead of constant Δλ.This is still a work in progress.The globaljetwatch spectrographs: A fibre-fed spectrograph for small telescopes
Proceedings of SPIE - The International Society for Optical Engineering 7014 (2008)
Abstract:
The GlobalJetWatch project (www.globaljetwatch.net) will place small (0.5-metre) commerical telescopes in four schools around the world. Each telescope will be equipped with a custom designed spectrograph, currently being built by the Astrophysics sub-department of the University of Oxford. The scientific goal of the project is to provide continual monitoring of a rosetta stone object, the micro-quasar SS433. In addition,the project has a significant out-reach element, aiming to involve school children on four-continents in front-line astronomical research. The spectrograph is a fibre-fed fixed format cross-dispersed echellete design providing R 6000 spectra from 4300-8500Å in a single exposure. The spectrograph is built almost entirely from off-the-shelf components. The four GlobalJetWatch sites (Australia, India, South Africa,Chile) will be commissioned in 2008/09. Here we present the baseline design of the spectrograph, and initial results from the prototype on-sky commissioning in Oxford.Why we need to go to Venus: The future of European Venus exploration
International Astronautical Federation - 59th International Astronautical Congress 2008, IAC 2008 3 (2008) 1622-1629
Abstract:
Venus is the most Earthlike planet we know besides our own, in terms of its size and distance from its parent star. It was probably formed from the same materials as the Earth and Mars, at a similar time - why then has it become so different?To address this key question, a team of 170+ scientists from around the world formulated the European Venus Explorer (EVE) mission proposal to the European Space Agency's Cosmic Vision Programme in 2007. Although it was not chosen in the 2007 selection round for programmatic reasons, it was rated a high priority for the future European Space Science so we take this opportunity to reiterate the science goals which motivated the EVE mission, and to discuss the status of technological and programmatic developments required to address these goals.SWIFT de-magnifying image slicer: Diffraction limited image slicing at optical wavelengths
Proceedings of SPIE - The International Society for Optical Engineering 7018 (2008)