High angular resolution far-infrared observations of Sagittarius B2

1992 ◽  
Vol 389 ◽  
pp. 338 ◽  
Author(s):  
Paul F. Goldsmith ◽  
Dariusz C. Lis ◽  
D. F. Lester ◽  
P. M. Harvey
Keyword(s):  
Angular Resolution ◽  
Far Infrared ◽  
High Angular Resolution ◽  
Infrared Observations

High angular resolution far-infrared observations of the W3 region

1980 ◽  
Vol 242 ◽  
pp. 601 ◽  
Author(s):  
M. W. Werner ◽  
E. E. Becklin ◽  
I. Gatley ◽  
G. Neugebauer ◽  
K. Sellgren ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Far Infrared ◽  
High Angular Resolution ◽  
Infrared Observations

scholarly journals Molecular Studies of Herbig-Haro Objects

1992 ◽  
Vol 150 ◽  
pp. 373-378
Author(s):  
Salvador Curiel
Keyword(s):  
Angular Resolution ◽  
Line Emission ◽  
High Angular Resolution ◽  
Molecular Line ◽  
Infrared Observations ◽  
Molecular Studies ◽  
Complex Variety ◽  
Molecular Lines ◽  
Hh Objects ◽  
Optical Wavelengths

Recent ultraviolet, infrared, millimeter and centimeter-wavelength observations have revealed that HH objects are also sources of molecular line emission. Infrared observations have shown that H2 line emission in HH objects presents a wide and complex variety of morphologies, being in most of the cases similar to that observed at optical wavelengths. New high-angular resolution radio observations of molecular lines have revealed that small high-density condensations are frequently found in association with HH objects. Below, a brief review of molecular emission in HH objects is presented.

scholarly journals The impact of clustering and angular resolution on far-infrared and millimeter continuum observations

2017 ◽  
Vol 607 ◽  
pp. A89 ◽  
Author(s):  
Matthieu Béthermin ◽  
Hao-Yi Wu ◽  
Guilaine Lagache ◽  
Iary Davidzon ◽  
Nicolas Ponthieu ◽  
...  
Keyword(s):  
Flux Density ◽  
Galaxy Evolution ◽  
Angular Resolution ◽  
Power Spectra ◽  
Far Infrared ◽  
High Angular Resolution ◽  
Strong Impact ◽  
Large Set ◽  
Number Counts ◽  
The Impact

Follow-up observations at high-angular resolution of bright submillimeter galaxies selected from deep extragalactic surveys have shown that the single-dish sources are comprised of a blend of several galaxies. Consequently, number counts derived from low- and high-angular-resolution observations are in tension. This demonstrates the importance of resolution effects at these wavelengths and the need for realistic simulations to explore them. We built a new 2 deg2 simulation of the extragalactic sky from the far-infrared to the submillimeter. It is based on an updated version of the 2SFM (two star-formation modes) galaxy evolution model. Using global galaxy properties generated by this model, we used an abundance-matching technique to populate a dark-matter lightcone and thus simulate the clustering. We produced maps from this simulation and extracted the sources, and we show that the limited angular resolution of single-dish instruments has a strong impact on (sub)millimeter continuum observations. Taking into account these resolution effects, we are reproducing a large set of observables, as number counts and their evolution with redshift and cosmic infrared background power spectra. Our simulation consistently describes the number counts from single-dish telescopes and interferometers. In particular, at 350 and 500 μm, we find that the number counts measured by Herschel between 5 and 50 mJy are biased towards high values by a factor ~2, and that the redshift distributions are biased towards low redshifts. We also show that the clustering has an important impact on the Herschel pixel histogram used to derive number counts from P(D) analysis. We find that the brightest galaxy in the beam of a 500 μm Herschel source contributes on average to only ~60% of the Herschel flux density, but that this number will rise to ~95% for future millimeter surveys on 30 m-class telescopes (e.g., NIKA2 at IRAM). Finally, we show that the large number density of red Herschel sources found in observations but not in models might be an observational artifact caused by the combination of noise, resolution effects, and the steepness of color- and flux density distributions. Our simulation, called Simulated Infrared Dusty Extragalactic Sky (SIDES), is publicly available.

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.

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