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20160304_MSciSpectrocopyLab
(04 Mar 2016,
JosephBayley
)
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Relative Depths Vega
To find a measure of the strength of a spectral line the area underneath the spectral line is found.
Equivalent width is a measure of the strength of a line and is defined as:
where
is a continuum function and
is the line profile.
Gaussian:
Lorentz:
Circle:
Background:
Line
Area
0.938
1.209
1.212
1.049
3.482
1.937
6.311
0.533
2.454
0.3068
0.3653
0.3677
0.3307
0.7762
0.5438
1.139
0.0953
0.5547
Quasar
To find the wavelength compared to position, the equation below was used,
First the four visible lines within Denebolas line were fit, the parameters for the fit are shown below,
Parameter
12.9
9195.6
10.18
16.545
The positions of each of these lines,
, could then be used with their actual wavelengths and fit with the grating equation above.
This gave a plot:
Map.png:
The parameters n and l were found to be n = 209.5 and l to be 25.44 mm.
where n in the slit density and l is the distance of the grating to the CCD.
however the grating is known to have a slit density of 200
therefore is this is set then the distance l is found to be 26.67 mm
Scan of peak
trying to find another function to fit to the scan of the peak,
Initially a parabola was used with the function,
HeliumScanparab
.png:
then a cosh function was used,
HeliumScancosh
.png:

JosephBayley
 03 Mar 2016
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Topic revision: r6  04 Mar 2016

JosephBayley
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