Modification of a Beckman Spectrophotometer for Direct Measurements of Spectral Energy Distribution of Light Sources

1963 ◽  
Vol 2 (3) ◽  
pp. 237 ◽  
Author(s):  
F. Grum
1962 ◽  
Vol 40 (10) ◽  
pp. 1329-1334 ◽  
Author(s):  
J. W. McAllan ◽  
F. A. Wood

The method describes an inexpensive modification of the Beckman DU spectrophotometer which permits rapid recording of the spectral energy distribution reflected from a magnesium carbonate surface. Comparison with a standard tungsten source corrects the effects of selective reflectivity and phototube response to different wavelengths. The method should be useful to biologists interested in the effects of light on organisms.


2011 ◽  
Vol 20 (3) ◽  
Author(s):  
S. Simić ◽  
L. Č. Popović ◽  
P. Jovanović

AbstractHere we consider the influence of microlensing on the spectrum of a lensed object with the angular size 5 μas accepting that the composite emission of this object originates from three different regions arranged around its center. We assume that the lensed object has three concentric regions with a black-body emission; the temperatures of these regions are 10 000 K, 7500 K and 5000 K. We investigate how the integral spectral energy distribution (SED) of such stratified source changes due to microlensing by a group of solarmass stars. We find that the SED and flux ratios in the photometric B, V and R passbands show considerable changes during a microlens event. This indicates that the flux anomaly observed in some lensed quasars may be caused by microlensing of a stratified object.


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