Lecture Notes

Beiglbock, Heidelberg, Germany W. Domcke, Garching, Germany B.-G. Englert, Singapore U. Frisch, Nice, France P. Hanggi, Augsburg, Germany G. Hasinger, Garching, Germany K. Hepp, ZUrich, Switzerland W. Hillebrandt, Garching, Germany D. Imboden, ZUrich, Switzerland R. L. Jaffe, Cambridge, MA, USA R. Lipowsky, Potsdam, Germany H. v. Lohneysen, Karlsruhe, Germany D. Sornette, Nice, France, and Zurich, Switzerland S. Theisen, Potsdam, Germany W. Weise, Garching, Germany J....

Interferometric Instrument at LBT

To complete our description of the adaptive instruments of LBT, we report in this section about the two interferometric instruments of the telescope. Remember that the LBT has two primary mirrors of 8.4 m with a center to center distance of 14 m, achieving the maximum equivalent resolution of a 23 m aperture. The opto-mechanical design of LBT allows one to obtain a homothetic interferometer in both the interferometric focal stations (top and central cylinders in Fig. 14). All interferometric...

The James Webb Space Telescope

The James Webb Space Telescope (JWST) is scheduled for launch in 2013 as an essential successor to the Hubble Space Telescope. It was originally known as the Next Generation Space Telescope but was renamed by NASA, with the Fig. 11. The James Webb Space Telescope. The spacecraft will be positioned at the Lagrange 2 point so that the sunshield will not only guard it from solar radiation but also from infrared radiation from the Earth to Moon system. Star and planet formation is one of the four...

Vlbi

An important subset of interferometer arrays are those operating on very long baselines, known as VLBI (very long baseline interferometer) arrays. The original such collaboration was the European VLBI Network (EVN) whose founding member telescopes included the 76-m Jodrell Bank telescope in the UK, the WSRT in the Netherlands,10 the 100-m Effelsberg antenna near Bonn, 10 The WSRT is itself a connected-element interferometer, but it is possible to insert phase delays into the arm of each element...

Angular Resolution And Distances Astronomy

Visibility of interference fringes as a function of slit separation (baseline length) Intensity distribution of source as a function of angle on the sky Visibility of interference fringes as a function of slit separation (baseline length) Fig. 2. Relation between source brightness as a function of angular distance and visibility of interference fringes as a function of slit separation (baseline length) seen that for small sources the visibility remains high out to large slit separation (in the...

Kinematics

Medium-resolution spectroscopic observations combined with AO of the inner regions of the DG Tau, RW Aur, HL Tauzcma, and SVS 13 microjets have been obtained with the integral field spectrograph OASIS(CFHT) in the optical domain 19, 28, 29 and or in the near-infrared with the IRCS(SUBARU) 37, 38 and NACO(VLT) 11 instruments in the long-slit mode. HST STIS long-slit observations have been also published on the DG Tau, RW Aur, TH 28 and LkHa321 microjets by 5, 6, 9, 45, 46 . Channel maps...

The Hubble Space Telescope

The HST is a long-lived space-based observatory working at a wide range of wavelengths (from the Far-UV to the Near-IR), resulting from the joint effort of the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). Launched in April 1990 and greatly extended in its scientific powers (through new instrumentation installed during four servicing missions with the NASA Space Shuttle), the HST has returned data of unique scientific value. The HST primary mirror has...

Effect of Atmospheric Turbulence on the Long Exposure PSF

It is important to be able to determine the telescope MTF when atmospheric perturbations are present. In other words, we want to compute the MTF of a telescope looking through the turbulent atmosphere. In the astronomical case, the exposure time is usually much longer than the atmospheric correlation time thus, the relevant MTF is the time-averaged MTF. Assuming ergodicity conditions, we will substitute the time average with a statistic average. For this computation, we will have to use the...

Atca

The Australia Telescope Compact Array is the most significant long-wavelength interferometer system in the southern hemisphere. It consists of six 22-m antennas over baselines of up to 6 km, with good high-frequency performance. Fibres and Sensitivity EVLA and e-MERLIN Important upgrades to Earth-based interferometers are currently under way. The major programmes involve an increase in sensitivity by using higher bandwidth. Currently signals are transmitted using transmission lines or microwave...

Basics Youngs Slits and Fourier Transforms 11 Youngs Slits

Interferometry begins with the Young's slits fringe pattern (Fig. 1). With a single point source emitting coherent radiation, interference fringes are observed, with constructive and destructive interference observed as the relative delay of the two interfering rays changes the separation of the fringes is X d, the wavelength of the light divided by the slit separation. If the source is made wider (Fig. 1b), we can think of it as a sequence of point sources each of which emits radiation, which...

LBT An Adaptive Telescope

To show an application of adaptive optics to an 8 m class telescope, we will briefly describe the AO system of the Large Binocular Telescope (LBT). The LBT with AO can be used in single dish or interferometric mode. The LBT is a binocular telescope made up of two 8.4 m primary mirrors. The mirrors are placed on the same mount and can work as two separate units or as an interferometer (the center to center distance of the two primary mirrors is 14 m). A drawing of the telescope is presented in...

Info

Example of differential phases (after removing atmospheric piston) and closure phase computation on an observed object with a rotating feature in the Br7 emission line in a Arae, 8 In first order approximation, the differential phase of Eq. (16) is a linear function that takes the generic form A 12 +27T (a2 a1) 6, where a 1 A is the wavenumber. Its slope 6 6p + 6o depends on the sum of atmospheric piston 6p, which varies frame by frame, and of the linear component of the object...

Producing the Image 21 Deconvolution

So far we have circumvented the major problem, which is that the interferometer response function has not been measured over the whole u, v plane. To do this at a single frequency would require enough telescopes to provide baselines at all possible separations and orientations, an expensive operation with substantial planning implications. Lack of this information means that the number of different images consistent with the data is infinite, since we could in principle fill in the unmeasured...