AL II emission-line strengths in low-density astrophysical plasmas

1992 ◽  
Vol 385 ◽  
pp. 375 ◽  
Author(s):  
F. P. Keenan ◽  
L. K. Harra ◽  
K. M. Aggarwal ◽  
W. A. Feibelman
Keyword(s):  
Emission Line ◽  
Low Density ◽  
Astrophysical Plasmas ◽  
Line Strengths

scholarly journals Si III emission line strengths in low density plasmas

1984 ◽  
Vol 209 (1) ◽  
pp. 1P-4P ◽  
Author(s):  
P. L. Dufton ◽  
F. P. Keenan ◽  
F. P. Kingston
Keyword(s):  
Emission Line ◽  
Low Density ◽  
Line Strengths

Relative quasar luminosities determined from emission line strengths

Nature ◽  
1978 ◽  
Vol 273 (5662) ◽  
pp. 431-435 ◽  
Author(s):  
Jack A. Baldwin ◽  
William L. Burke ◽  
C. Martin Gaskell ◽  
E. J. Wampler
Keyword(s):  
Emission Line ◽  
Line Strengths

Is there a Relation between Optical Emission Line Strengths and Continuum Shapes?

1989 ◽  
pp. 187-188
Author(s):  
Belinda J. Wilkes ◽  
Martin Elvis ◽  
Jonathan McDowell
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
Line Strengths

scholarly journals The Solar X-Ray Line Spectrum 5.5 – 12Å

1984 ◽  
Vol 86 ◽  
pp. 136-136
Author(s):  
D.L. McKenzie
Keyword(s):  
Wavelength Range ◽  
Theoretical Calculations ◽  
High Sensitivity ◽  
Line Spectrum ◽  
Low Density ◽  
X Ray ◽  
R Ratio ◽  
G Ratio ◽  
Limiting Value ◽  
Line Strengths

The SOLEX X-ray spectrometers on the USAF P78–1 satellite have measured solar X-ray spectra in the 5.5–12Å range under a variety of flaring and nonflaring conditions. High sensitivity, obtained by summing data from several successive spectral scans, enabled the detection of 80 lines, 17 of which remain unidentified. The stronger lines were observed with individual scans during the course of flare development. This capability, along with the use of nonflare spectra, facilitated the identification of several lines. The lines of Fe XXII - XXIV, present in hot flare plasmas, are prominent in this wavelength range. For many of these lines, theoretical and observed line strengths will be compared. Diagnostically useful line ratios were evaluated for the helium-like species Mg XI, Al XII, and Si XIII. The density-sensitive R ratio was consistent with theoretical calculations of the low-density limiting value for Mg XI and Si XIII, the only species for which it was evaluated. In all cases the G ratio was below calculated values.

scholarly journals Understanding the Nebular Spectrum of SN 1987A

1996 ◽  
Vol 145 ◽  
pp. 223-234
Author(s):  
Richard McCray
Keyword(s):  
Emission Line ◽  
Infrared Emission ◽  
Emission Lines ◽  
Low Density ◽  
Simple Method ◽  
Sn 1987A ◽  
Hydrogen Recombination ◽  
Inner Envelope

The nebular spectra of supernovae differ from those of better-known emission nebulae in that many of the emission lines are optically thick. Here we sketch the theory for interpreting such spectra, and show how it can be used to interpret prominent emission line systems in the spectrum of SN 1987A. As examples, we describe: (1) a simple method to infer the density of OI from observations of the evolution of the doublet ratio in [O I]λλ6300; (2) new kind of hydrogen recombination hne spectrum; (3) an analysis showing that the Call infrared emission lines must come from primordial, not newly-synthesized, calcium; (4) a theory for the Fe/Co/Ni emission lines that shows that the inner envelope of SN 1987A must have a foamy texture, in which low density radioactive bubbles of Fe/Co/Ni reside in a massive substrate of hydrogen, helium, and other elements.

EXCITONS IN COLLOIDAL CuI PARTICLES DISPERSED IN A KI CRYSTAL

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3789-3792
Author(s):  
T. HIRAI ◽  
K. EDAMATSU ◽  
T. ITOH ◽  
Y. HARADA ◽  
S. HASHIMOTO
Keyword(s):  
Binding Energy ◽  
Emission Line ◽  
Low Temperatures ◽  
High Density ◽  
Luminescence Spectra ◽  
Low Density ◽  
Small Binding Energy ◽  
Excitonic States ◽  
Exciton Transitions

We have investigated the luminescence spectra of colloidal CuI particles dispersed in a KI crystal under low- and high-density excitations of the CuI particles at low temperatures. Under the low-density excitation, we have observed the luminescence of both confined and bulk-like exciton transitions in the CuI particles with zincblende and two kinds of hexagonal structures. In the bulk-like particles with the zincblende structure, the emission line of bound excitons with small binding energy of ~5 meV has been recognized. The biexciton luminescence has been observed under the high-density excitation. We discuss the origins of the various excitonic states observed in the CuI particles dispersed in the KI crystal.

scholarly journals New Models for Massive Star Populations in Young Starbursts: Summary of the Models and Applications

1999 ◽  
Vol 186 ◽  
pp. 285-285
Author(s):  
Daniel Schaerer ◽  
William D. Vacca
Keyword(s):  
Emission Line ◽  
Stellar Evolution ◽  
Massive Star ◽  
Optical Emission ◽  
Emission Lines ◽  
Evolutionary Synthesis ◽  
Stellar Spectra ◽  
New Models ◽  
Helium Emission ◽  
Line Strengths

Using the latest stellar evolution models, theoretical stellar spectra, and a compilation of observed emission line strengths from Wolf-Rayet (WR) stars, we have constructed evolutionary synthesis models for young starbursts (Schaerer & Vacca 1997; see also Schaerer 1996). We provide detailed predictions of UV and optical emission line strengths for both the WR stellar lines and the major nebular hydrogen and helium emission lines, as a function of several input parameters related to the starburst episode.

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