scholarly journals Positions and 1665 MHz Line Profiles for 10 Northern OH Emission Sources

1974 ◽  
Vol 27 (4) ◽  
pp. 629 ◽  
Author(s):  
JL Caswell ◽  
BJ Robinson
Keyword(s):  
Circular Polarization ◽  
Emission Sources ◽  
Line Profiles

Positions with r.m.s. errors of about 20" arc have been determined for the stronger OH emission sources discovered in two northern searches. Line profiles at 1665 MHz with 1 kHz resolution are presented for both senses of circular polarization.

scholarly journals 18 cm Observations of 19 New Southern OH Emission Sources

1974 ◽  
Vol 27 (4) ◽  
pp. 575 ◽  
Author(s):  
BJ Robinson ◽  
JL Caswell ◽  
WM Goss
Keyword(s):  
Milky Way ◽  
Emission Sources ◽  
Line Profiles ◽  
General Properties

In a search for 1665 MHz OH emission in the southern Milky Way, 19 new sources have been discovered. Line profiles of all four 18 cm transitions are presented for all but one of the sources, and we discuss the general properties of the sources and their distribution in relation to the positions searched.

Line Interactions in Saturated Masers

1971 ◽  
Vol 2 (1) ◽  
pp. 34-36
Author(s):  
A. G. Bromley
Keyword(s):  
Circular Polarization ◽  
Physical Process ◽  
Emission Sources ◽  
Physical Mechanisms ◽  
High Degree

Two important problems have emerged from observations of 18 cm OH emission sources that remain substantially unanswered by existing theories. The first is the problem of the origin of the high degree of circular polarization that is frequently observed. The second is what I have called the ‘problem of variety’: is it necessary to invoke a number of different physical mechanisms to explain the variety of qualitatively different behaviours observed, or can these different behaviours be explained by variations of one basic physical process?

Angular size of OH emission regions

1967 ◽  
Vol 31 ◽  
pp. 71-72
Author(s):  
B. F. Burke ◽  
P. P. Crowther ◽  
J. M. Moran ◽  
A. E. E. Rogers ◽  
J. A. Ball ◽  
...  
Keyword(s):  
Angular Size ◽  
Emission Sources ◽  
Ngc 6334

Interferometry gives effective diameters less than 20″ for the OH emission sources in W3and Sgr B2. The sources in W49and NGC 6334 contain two or more components, some of which are smaller than 25″.

Structuring, Motions and Shapes of Corona Emission Line Profiles

1994 ◽  
Vol 144 ◽  
pp. 421-426
Author(s):  
N. F. Tyagun
Keyword(s):  
Emission Line ◽  
Filling Factor ◽  
Direct Relationship ◽  
Coronal Plasma ◽  
Line Of Sight ◽  
Line Profiles ◽  
The Difference ◽  
Yellow Line ◽  
Red Line

AbstractThe interrelationship of half-widths and intensities for the red, green and yellow lines is considered. This is a direct relationship for the green and yellow line and an inverse one for the red line. The difference in the relationships of half-widths and intensities for different lines appears to be due to substantially dissimilar structuring and to a set of line-of-sight motions in ”hot“ and ”cold“ corona regions.When diagnosing the coronal plasma, one cannot neglect the filling factor - each line has such a factor of its own.

Effects of Ambipolar Diffusion on Prominence Thread Models

1994 ◽  
Vol 144 ◽  
pp. 315-321 ◽  
Author(s):  
M. G. Rovira ◽  
J. M. Fontenla ◽  
J.-C. Vial ◽  
P. Gouttebroze
Keyword(s):  
Energy Balance ◽  
Transition Region ◽  
Ambipolar Diffusion ◽  
Line Profiles ◽  
Balance Equations ◽  
Model Calculations ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Theoretical Structure

AbstractWe have improved previous model calculations of the prominence-corona transition region including the effect of the ambipolar diffusion in the statistical equilibrium and energy balance equations. We show its influence on the different parameters that characterize the resulting prominence theoretical structure. We take into account the effect of the partial frequency redistribution (PRD) in the line profiles and total intensities calculations.

The Interpretation of Line Profiles

1977 ◽  
Vol 36 ◽  
pp. 191-215
Author(s):  
G.B. Rybicki
Keyword(s):  
Magnetic Fields ◽  
Atomic Physics ◽  
Velocity Fields ◽  
Spectral Lines ◽  
Inhomogeneous Structure ◽  
The Sun ◽  
Line Profiles ◽  
Physical Phenomena

Observations of the shapes and intensities of spectral lines provide a bounty of information about the outer layers of the sun. In order to utilize this information, however, one is faced with a seemingly monumental task. The sun’s chromosphere and corona are extremely complex, and the underlying physical phenomena are far from being understood. Velocity fields, magnetic fields, Inhomogeneous structure, hydromagnetic phenomena – these are some of the complications that must be faced. Other uncertainties involve the atomic physics upon which all of the deductions depend.

High resolution at low voltage: A new approach

1989 ◽  
Vol 47 ◽  
pp. 76-77
Author(s):  
Arthur V. Jones
Keyword(s):  
Low Voltage ◽  
Emission Sources ◽  
New Approach ◽  
Design Concepts ◽  
Probe Diameter ◽  
Low Voltage Operation ◽  
Sufficient Intensity ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Immersion Type

With the introduction of field-emission sources and “immersion-type” objective lenses, the resolution obtainable with modern scanning electron microscopes is approaching that obtainable in STEM and TEM-but only with specific types of specimens. Bulk specimens still suffer from the restrictions imposed by internal scattering and the need to be conducting. Advances in coating techniques have largely overcome these problems but for a sizeable body of specimens, the restrictions imposed by coating are unacceptable.For such specimens, low voltage operation, with its low beam penetration and freedom from charging artifacts, is the method of choice.Unfortunately the technical dificulties in producing an electron beam sufficiently small and of sufficient intensity are considerably greater at low beam energies — so much so that a radical reevaluation of convential design concepts is needed.The probe diameter is usually given by

Hydrogen line profiles at low densities

1984 ◽  
Vol 9 (4) ◽  
pp. 697-704 ◽  
Author(s):  
C. Stehlé ◽  
N. Feautrier
Keyword(s):  
Line Profiles ◽  
Hydrogen Line
Sign in / Sign up

Export Citation Format

Share Document