
META TOPICPARENT 
name="StewartBoogertPhotometry2016" 
 AnishaVadher  13 Oct 2016
 Working out how much background for each pixel
 Plotted a histogram of number of photoelectrons against the frequency for a 0.1s exposure in the dark frame which follows a Gaussian distribution


> >  

 Number of photoelectrons = pixel value (ADU) * Gain
 Gain = 2.3 e/ADU (value from PH2900 report)
 From the histogram I will obtain the value at the peak and the error from the FWHM
 Error in the peak = FWHM/2.35
 I will get these statistics for each exposure time in the dark frames that I have taken and plot the peak value as a function of exposure time and the error as a function of exposure time.
 There are big gaps between the bins which I am not sure why.


> > 
 Edit  the gaps are due to the fact that the histogram only takes integer values so increasing the number of bins leads to more gaps in the histogram.
 Histrogram of number of photoelectrons for a 0.1s exposure in the dark frame with 45 bins.:


 Also plotted a histogram for the sum of pixel along the xaxis values against frequency for a 0.1s exposure in the dark frame which follows a Poisson distribution
 The histograms from the sum of pixels along the yaxis follows a Gaussian distribution.


> > 
 Plotted the median intensity of the pixels as a function of exposure time using the values given from the image using np.median in python. I am yet to work out the errors.
 The median intensity as a function of exposure time.:


META FILEATTACHMENT 
attachment="Histogram_of_number_of_photoelectrons_for_0.1s_exposure.png" attr="" comment="Histrogram of number of photoelectrons for a 0.1s exposure in the dark frame." date="1476399535" name="Histogram_of_number_of_photoelectrons_for_0.1s_exposure.png" path="Histogram of number of photoelectrons for 0.1s exposure.png" size="18803" user="zyva858" version="1" 
META FILEATTACHMENT 
attachment="Difference_between_summing_across_xaxis_and_yaxis.png" attr="" comment="Histograms to show the difference between summing across xaxis and yaxis for 0.1s exposure dark frame" date="1476399674" name="Difference_between_summing_across_xaxis_and_yaxis.png" path="Difference between summing across xaxis and yaxis.png" size="39734" user="zyva858" version="1" 


> > 
META FILEATTACHMENT 
attachment="Histogram_of_number_of_photoelectrons_for_0.1s_exposure_45_bins.png" attr="" comment="Histrogram of number of photoelectrons for a 0.1s exposure in the dark frame with 45 bins." date="1476442640" name="Histogram_of_number_of_photoelectrons_for_0.1s_exposure_45_bins.png" path="Histogram_of_number_of_photoelectrons_for_0.1s_exposure_45_bins.png" size="19103" user="zyva858" version="1" 
META FILEATTACHMENT 
attachment="The_median_intensity_as_a_function_of_exposure_time.png" attr="" comment="The median intensity as a function of exposure time." date="1476443160" name="The_median_intensity_as_a_function_of_exposure_time.png" path="The_median_intensity_as_a_function_of_exposure_time.png" size="33910" user="zyva858" version="1" 
