The influence of spectral resolution on line blending and wavelength positions in the solar UV spectrum

Solar Physics ◽  
1980 ◽  
Vol 65 (2) ◽  
pp. 405-409 ◽  
Author(s):  
A. Greve ◽  
C. D. McKeith
Keyword(s):  
Spectral Resolution ◽  
Uv Spectrum ◽  
On Line ◽  
Solar Uv ◽  
Solar Uv Spectrum

High Resolution Observations of Solar Velocity Fields from Spacecraft and Rockets Using Spectroscopic Methods

1977 ◽  
Vol 36 ◽  
pp. 75-103
Author(s):  
Oran R. White
Keyword(s):  
High Resolution ◽  
Transition Region ◽  
Velocity Fields ◽  
Spectroscopic Methods ◽  
Uv Spectrum ◽  
Space Experiments ◽  
The Future ◽  
Solar Uv ◽  
Solar Uv Spectrum

Progress in the development of rocket and satellite spectrometers has now given us the opportunity to study the solar UV spectrum for evidence of mass motions in the chromospheric-coronal transition region. It is my intent to discuss briefly the motivation behind such space experiments, to summarize the few existent observational results, and to suggest relevant programs to exploit the opportunities offered by space experiments in the future.

On the Calibration of a Solar UV Radiometer to Measure Broadband UV Radiation from Blacklight Lamps

2002 ◽  
Vol 124 (3) ◽  
pp. 317-319 ◽  
Author(s):  
Sanjay Vijayaraghavan and ◽  
D. Y. Goswami
Keyword(s):  
Energy Spectrum ◽  
Uv Radiation ◽  
Correction Factor ◽  
Calibration Procedure ◽  
Uv Spectrum ◽  
Laboratory Conditions ◽  
Instrument Response ◽  
Solar Uv ◽  
Uv Lamps ◽  
Solar Uv Spectrum

Experiments in photocatalysis often involve the use of blacklight UV lamps to simulate the solar UV spectrum under indoor laboratory conditions. solar UV radiometers (such as the Eppley TUVR) which are calibrated for solar UV spectrum require correction when used to measure the energy from a lamp array. This paper describes a transfer calibration procedure that was used to determine instrument response to the blacklight lamp energy spectrum. It also shows theoretically and experimentally that a correction factor of about 1.15 is needed to use a solar UV radiometer for measurements of outputs from the lamps.

scholarly journals Opacity Sources in the UV Spectrum of the Sun

1971 ◽  
Vol 2 ◽  
pp. 495-502
Author(s):  
R. M. Bonnet ◽  
D. Sacotte
Keyword(s):  
Neutral Hydrogen ◽  
Wavelength Region ◽  
Absorption Lines ◽  
Uv Spectrum ◽  
Significant Difference ◽  
Resonance Doublet ◽  
Solar Uv ◽  
Emission Core ◽  
Limb Darkening ◽  
The Continuum

In the past three or four years a great deal of attention has been given to the interpretation of the solar UV continuum. Several sets of intensity and limb-darkening measurements made from satellite, rocket and balloon borne instruments are now available, which allow comparisons to be made with theoretical computations. The main purpose of this paper is to discuss these comparisons, we restrict this discussion to the wavelength region between 3000 Å and 1680 Å, in which a significant difference between the observations and the computations still exists. The lines in this wavelength region which are of relevance to the continuum opacity are listed as follows:the Ly-α line of neutral hydrogen at 1216 Å which appears as a strong emission line;the resonance doublet of Mgװ at 2795 Å and 2803 Å which causes a broad depression in the solar continuum and shows an emission core similar in shape to the Ly-α line;the auto-ionization doublet of AlI at 1932 Å and 1936 Å, which appears as two broad absorption features;several absorption lines such as Mgi 2852 Å Sii 2881 Å;many FeI and FeII absorption lines.There are also several discontinuities in the continuum emitted between the lines in the spectrum between 1216 Å and 3000 Å. The most important ones are located at 2500 Å, 2085 Å and 1680 Å, which correspond to the photoionization edges of MgI, AlI and SiI respectively.

scholarly journals The NIRSPEC Brown Dwarf Spectroscopic Survey

2003 ◽  
Vol 211 ◽  
pp. 385-388 ◽  
Author(s):  
Ian S. McLean ◽  
M. R. McGovern ◽  
Lisa Prato ◽  
Adam J. Burgasser ◽  
J. Davy Kirkpatrick
Keyword(s):  
Spectral Resolution ◽  
Brown Dwarfs ◽  
Spectral Classification ◽  
Brown Dwarf ◽  
Low Mass Stars ◽  
Spectral Signatures ◽  
The Status ◽  
Infrared Spectral ◽  
On Line ◽  
Low Mass

This paper describes the status of a new 0.9 – 2.4 μm spectroscopic survey of low-mass stars and brown dwarfs. Flux-calibrated spectra of 30 objects from M6 to T8 have been obtained with a uniform spectral resolution of R=2,000. For the J-band alone, 60 objects have been observed. In addition, we have obtained the first sequence of spectra at R=20,000 (15 km/s) showing the detailed behavior of the J-band potassium doublets over the same range in spectral type. A few sources have been monitored for radial velocity variations, but none have been detected at the ±1–2 km/s level. Preliminary infrared spectral classification indices have been derived and several young brown dwarfs show clear spectral signatures of lower gravity. Our survey will be available on-line in the future.

Axial Observation of X-Ray Spectra from a Beam-Foil Source

1988 ◽  
Vol 102 ◽  
pp. 339-342
Author(s):  
J.M. Laming ◽  
J.D. Silver ◽  
R. Barnsley ◽  
J. Dunn ◽  
K.D. Evans ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Axis ◽  
Doppler Broadening ◽  
X Ray ◽  
Beam Foil

AbstractNew observations of x-ray spectra from foil-excited heavy ion beams are reported. By observing the target in a direction along the beam axis, an improvement in spectral resolution, δλ/λ, by about a factor of two is achieved, due to the reduced Doppler broadening in this geometry.

Ultrastructural changes in murine lymphoma cells exposed to ultraviolet-A radiation

1991 ◽  
Vol 49 ◽  
pp. 104-105
Author(s):  
Delma P. Thomas ◽  
Dianne E. Godar
Keyword(s):  
Medical Devices ◽  
Blood Cells ◽  
White Blood Cells ◽  
Consumer Products ◽  
Ultrastructural Changes ◽  
Ultraviolet A ◽  
Uv Spectrum ◽  
Lymphoma Cells ◽  
Murine Lymphoma ◽  
Transmission Electron

Ultraviolet radiation (UVR) from all three waveband regions of the UV spectrum, UVA (320-400 nm), UVB (290-320 nm), and UVC (200-290 nm), can be emitted by some medical devices and consumer products. Sunlamps can expose the blood to a considerable amount of UVR, particularly UVA and/or UVB. The percent transmission of each waveband through the epidermis to the dermis, which contains blood, increases in the order of increasing wavelength: UVC (10%) < UVB (20%) < UVA (30%). To investigate the effects of UVR on white blood cells, we chose transmission electron microscopy to examine the ultrastructure changes in L5178Y-R murine lymphoma cells.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

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