GI2T/REGAIN: multiple systems studied by high angular resolution optical interferometry

2000 ◽  
Author(s):  
Nathalie D. Thureau ◽  
Daniel Bonneau ◽  
Thierry Girard
Keyword(s):  
Angular Resolution ◽  
Optical Interferometry ◽  
High Angular Resolution ◽  
Multiple Systems

scholarly journals Simulation and Analysis of Telescopic Photonic Beam Combiner for Stellar Interferometry in Labview

2019 ◽  
Vol 8 (9S) ◽  
pp. 230-236
Keyword(s):  
Angular Resolution ◽  
Mechanical Stability ◽  
Optical Interferometry ◽  
Physical Contact ◽  
Optical Methods ◽  
High Angular Resolution ◽  
Multiple Observations ◽  
Beam Combiner ◽  
Stellar Interferometry ◽  
The Universe

The optical methods are the sensitive and subtle techniques of conducting optical investigations without any physical contact. They are both accurate and fast at the same time which provides an ease of having multiple observations. The need of optical interferometry has been increased at a very quick pace due to its high range of applications, from surface testing to locating of extra-solar planets in the universe. Optical Interferometry is a process or technique of combining light from various telescopes for calculating the angular resolution. The technique of optical interferometry helps astronomers for achieving a high angular resolution, that is not possible with the conventional telescopes. Optical approaches are the best approaches for non-contact evaluations, and these are accurate and fast. Due to optical nature of the interferometry, this process is used in various fields, and today it has become one of the important areas of research. Integrated Optics (IO) beam combiners are an efficient and compact technology to combine light interferometrically collected by multiple telescopes. IO beam combiner is based on the modal filtering properties of waveguides or fibers, and it improves thermo-mechanical stability, because of the characteristic rigidity of IO component substrate. Other advantages of this technology are miniaturization and non-existence of alignment needs. Several IO beam combiners are being proposed and tested nowadays. The purpose of this paper is to investigate different techniques used to develop interferometric instrument from previous researches and to simulate the technique suggested by Ermann in Labview.

scholarly journals The Future of mm/submm Interferometry: The ALMA Project

2001 ◽  
Vol 200 ◽  
pp. 547-554 ◽  
Author(s):  
Stéphane Guilloteau
Keyword(s):  
Star Formation ◽  
Angular Resolution ◽  
Thermal Emission ◽  
Binary Star ◽  
High Angular Resolution ◽  
Multiple Systems ◽  
The Future ◽  
Frequency Coverage ◽  
Very High

ALMA, the Atacama Large Millimeter / Sub-millimeter Array will be the first instrument allowing very high angular resolution (down to 0.01″) with sufficient sensitivity to image thermal emission from dust and molecules in proto-planetary disks at wavelengths where these disks are optically thin. Its unsurpassed characteristics will make it a premier instrument to study the formation of binary and multiple systems. I present here the projected characteristics of ALMA, in particular the expected sensitivities and frequency coverage, and illustrates some possible applications relevant to the study of binary star formation.

scholarly journals Small-scale properties of Class 0 protostars from the CALYPSO IRAM-PdBI survey

2015 ◽  
Vol 11 (S315) ◽  
pp. 114-117
Author(s):  
Anaëlle Maury ◽  
Philippe André ◽  
Sébastien Maret ◽  
Arnaud Belloche ◽  
Claudio Codella ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Angular Resolution ◽  
Dust Emission ◽  
Continuum Emission ◽  
Small Scale ◽  
High Angular Resolution ◽  
Multiple Systems ◽  
Small Scales ◽  
Molecular Lines ◽  
Scale Properties

AbstractBecause the formation of protostars is believed to be closely tied to the angular momentum problem of star formation, characterizing the properties of the youngest disks around Class 0 objects is crucial. However, not much is known on the structure of the youngest protostellar envelopes, on the small scales at which disks and multiple systems are observed around more evolved YSOs, due to a lack of comprehensive high angular resolution observations (probing <100 AU). In order to tackle this issue, we conducted a large observing program with the IRAM Plateau de Bure interferometer (PdBI): the CALYPSO survey, providing us with detailed maps of molecular lines and millimeter continuum emission, probing scales down to ~30–50 au towards a sample of 17 Class 0 protostars. Here we present our analysis of the CALYPSO dust continuum emission maps, constraining disk properties of the Class 0 protostars in our sample. We show that large, r > 50 au, disk structures are not observed in most Class 0 protostars from our sample, which can be described by various envelope models reproducing satisfactorily the intensity distribution of the dust emission at all scales from 50 au to 5000 au.

scholarly journals High Angular Resolution and Young Stellar Objects: Imaging the Surroundings of MWC 158 by Optical Interferometry

2013 ◽  
Vol 59 ◽  
pp. 141-154
Author(s):  
J. Kluska ◽  
F. Malbet ◽  
J.-P. Berger ◽  
M. Benisty ◽  
B. Lazareff ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Optical Interferometry ◽  
Young Stellar Objects ◽  
High Angular Resolution ◽  
Stellar Objects

Small-Angle Electron Scattering (SAES) of Polymers

1985 ◽  
Vol 43 ◽  
pp. 78-79
Author(s):  
Ralph Oralor ◽  
Pamela Lloyd ◽  
Satish Kumar ◽  
W. W. Adams
Keyword(s):  
Electron Scattering ◽  
Small Angle ◽  
Angular Resolution ◽  
Structural Features ◽  
Objective Lens ◽  
High Angular Resolution ◽  
Push Button ◽  
First Case ◽  
Diffraction Mode ◽  
Very High

Small angle electron scattering (SAES) has been used to study structural features of up to several thousand angstroms in polymers, as well as in metals. SAES may be done either in (a) long camera mode by switching off the objective lens current or in (b) selected area diffraction mode. In the first case very high camera lengths (up to 7Ø meters on JEOL 1Ø ØCX) and high angular resolution can be obtained, while in the second case smaller camera lengths (approximately up to 3.6 meters on JEOL 1Ø ØCX) and lower angular resolution is obtainable. We conducted our SAES studies on JEOL 1ØØCX which can be switched to either mode with a push button as a standard feature.

Large-angle convergent-beam electron-diffraction study of coherent precipitates and decorated dislocations

1996 ◽  
Vol 54 ◽  
pp. 1002-1004
Author(s):  
J.M.K. Wiezorek ◽  
H.L. Fraser
Keyword(s):  
Electron Diffraction ◽  
Angular Resolution ◽  
Large Angle ◽  
Electron Diffraction Study ◽  
Convergent Beam Electron Diffraction ◽  
Crystal Defects ◽  
High Angular Resolution ◽  
Beam Electron ◽  
Diffraction Plane ◽  
Convergent Beam

Conventional methods of convergent beam electron diffraction (CBED) use a fully converged probe focused on the specimen in the object plane resulting in the formation of a CBED pattern in the diffraction plane. Large angle CBED (LACBED) uses a converged but defocused probe resulting in the formation of ‘shadow images’ of the illuminated sample area in the diffraction plane. Hence, low-spatial resolution image information and high-angular resolution diffraction information are superimposed in LACBED patterns which enables the simultaneous observation of crystal defects and their effect on the diffraction pattern. In recent years LACBED has been used successfully for the investigation of a variety of crystal defects, such as stacking faults, interfaces and dislocations. In this paper the contrast from coherent precipitates and decorated dislocations in LACBED patterns has been investigated. Computer simulated LACBED contrast from decorated dislocations and coherent precipitates is compared with experimental observations.

Binary Cepheids From High-Angular Resolution

2015 ◽  
Vol 71-72 ◽  
pp. 187-188
Author(s):  
A. Gallenne ◽  
A. Mérand ◽  
P. Kervella
Keyword(s):  
Angular Resolution ◽  
High Angular Resolution
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