scholarly journals Physics of Radiatively Driven Winds by High Angular Resolution Observations (HARO)

1999 ◽  
Vol 169 ◽  
pp. 115-118
Author(s):  
Ph. Stee ◽  
D. Bonneau ◽  
D. Mourard ◽  
F. Vakili
Keyword(s):  
Energy Distribution ◽  
Line Profile ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
Wind Model ◽  
Polarization Data ◽  
Hot Stars ◽  
B Stars ◽  
Continuum Energy

AbstractNumerous models have been developed during the last two decades which try to fit a small number of “classical” observables as closely as possible (i.e Hα line profile and continuum energy distribution or polarization data). Nevertheless, little has been done to include High Angular Resolution Observations (HARO) in simulations in spite of the fact that such data can strongly constrain radiative wind models. In the following, we shall review recent results coming from HARO of active B stars and we shall focus on our radiative wind model for active hot stars which integrates these measurements.

scholarly journals Michelson-Spectro-Interferometry (MSI) of Be stars envelopes with the GI2T Interferometer

1995 ◽  
Vol 149 ◽  
pp. 365-368
Author(s):  
Ph. Stee ◽  
D. Bonneau ◽  
P. Lawson ◽  
F. Morand ◽  
D. Mourard ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Michelson Interferometer ◽  
Numerical Code ◽  
High Angular Resolution ◽  
Be Stars ◽  
Wind Model ◽  
Long Baseline ◽  
Balmer Lines ◽  
Extended Sources ◽  
Resolution Data

AbstractThe GI2T is an optical long-baseline Michelson interferometer which analyses dispersed stellar fringes in the multi-speckle mode with a spectral resolution of one Angstrom while the spatial resolution is about one milliarcsecond. This makes the GI2T a powerful instrument able to perform MSI of extended sources like Be stars or shell stars. In order to interpret these data we have developed a latitude dependent radiative wind model for Be stars. This numerical code enables us to compare directly computed 2D maps in some Balmer lines (Hα and Hβ) with high angular resolution data of some Be stars.

Fine Structure in Channeling Lines

1969 ◽  
Vol 24 (4) ◽  
pp. 660-663 ◽  
Author(s):  
M. Rogge ◽  
W. Dünnweber ◽  
C. Mayer-Böricke
Keyword(s):  
Fine Structure ◽  
Single Crystals ◽  
Line Profile ◽  
Angular Resolution ◽  
Angular Distributions ◽  
High Angular Resolution ◽  
Uniform Thickness ◽  
Crystal Potential ◽  
Structure Pattern ◽  
Experimental Detection

Abstract It is shown by calculations (classical treatment) that fine structure is to be expected in angular distributions of channeled particles. This fine structure will be superimposed on the normal smooth channeling line profile. It is due to coherent channeling. It requires high angular resolution and thin single crystals of uniform thickness for experimental detection. The fine structure pattern is sensitive to the details of the crystal potential.

Direct Optical Imaging of Be Disks

2000 ◽  
Vol 175 ◽  
pp. 129-140
Author(s):  
Philippe Stee
Keyword(s):  
Optical Imaging ◽  
Spectral Resolution ◽  
Role Models ◽  
Angular Resolution ◽  
High Spectral Resolution ◽  
High Angular Resolution ◽  
Be Stars ◽  
Hot Stars ◽  
Time Consumption ◽  
Circumstellar Environment

AbstractInterferometry in the visible now provides milliarcsecond spatial resolution and thus can be used for studying the circumstellar environment of Be stars. In this review I will first introduce the two basic quantities that an interferometer can access: the modulus and the phase of the visibility. I will illustrate how these two quantities can be used to understand the physics of Be disks through recent results from the VLA, the MkII and the GI2T interferometers. I will insist on the importance and the potential of coupling high angular resolution with high spectral resolution to the study of Be disks. Since the possibility of direct optical imaging of Be disks will be limited due to complexity and time consumption, I will present the role models can play in interpreting high angular resolution observations when direct imaging become difficult. Finally I will draw up a list of challenging objectives for the next generation of synthetic arrays (GI2T/REGAIN, Keck, ST3, VLTI) which will bring new understanding of active hot stars physics.

scholarly journals Search for cluster candidates in the ukidss database

2009 ◽  
Vol 5 (S266) ◽  
pp. 400-400
Author(s):  
Mario Gennaro ◽  
Wolfgang Brandner ◽  
Thomas Henning ◽  
Andrea Stolte
Keyword(s):  
Angular Resolution ◽  
Galactic Plane ◽  
High Angular Resolution ◽  
Mid Infrared ◽  
B Stars ◽  
The Galaxy ◽  
Inner Region ◽  
High Degree ◽  
Significant Effort ◽  
Infrared Survey

Abstractukidss gps is a deep and high-angular-resolution survey of the Galactic plane in the J, H, and K bands. Using this survey, we searched the inner region of the Galaxy (|l| < 10°) for young cluster candidates associated with molecular bubbles (MBs). The latter are observed in the mid-infrared survey glimpse ii. The underlying idea is that MBs may be blown out by powerful sources, such as young O and B stars; some of the MBs in the sample are indeed associated with Hii regions, a hint of the presence of young stars. One of the major observational problems in the Galactic plane is the high degree of interstellar absorption and its spatial variability. A significant effort is also devoted to quantifying this issue.

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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