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Discussed expected spectrums, line broadening mechanisms, line shapes: Thermal broadening Gaussian Pressure/collisional broadening Lorentzian...

Poisson variables N {adu} is not poisson, N {pe} is poisson N {pe} G N {adu} trial.fit: trial.fit single frame to start data analysis...

Spectrum Initially the fits file was loaded into python, the image was then projected onto the x axis to obtain a spectrum. This was in the units of N {adu} against...

set up MaxIm DL, set up ST 7E camera: SBIG Universal, Parallel connection connect NO LIGHT SOURCE: set exposure time t 0.8s, initial temp 20 degrees, took...

Present: Joe Bayley, Ashlea Kemp, Elena Cukanovaite, David Hadden, Professor Boogert, Professor Cowan Select one peak of data, fit gaussian to peak with term...

Set Up Turned on spectrometer, Cadmium lamp and camera. Set the cooler to 5 deg C initally (Temperature outside is about 13 deg C). Set exposure time...

Finding errors in spectra Initially we wanted to find the errors in the spectra plot below. A discrete number of photons will hit the pixel in a certain amount of...

Present: Joe Bayley, Ashlea Kemp, Elena Cukanovaite, David Hadden, Professor Cowan Find the errors in the plot of the spectra of cadmium. Use these errors...

Present Joe Bayley, Ashlea Kemp, Elena Cukanovaite, David Hadden, Professor Cowan, Professor Boogert Find the convolution of two function to fit to the spectral...

Hot Pixels The background data of a dark frame was plotted at an exposure of 2 s and a temperature of 10deg. Background hot.png: The large spikes in...

Meeting Notes Present: Ashlea Kemp, Joe Bayley, Elena Cukanovaite, David Hadden, Professor Boogert, Professor Cowan Make sure to include some mathematics onto...

Standard Deviation vs Focus/Angle plots Normalised %$N {\mathrm{pe}}$% into %$N {\mathrm{pe}}$% per pixel number per exposure time and replotted graphs of %$...

For hot pixel look for a p value %$N {\mathrm{DOF}} N {\mathrm{data points}} N {\mathrm{fitted params}}$% %$E \chi^{2} N {\mathrm{DOF}}$%...

Data taking with further lamps 2 remaining lamps: Lamp 1 Sodium Lamp 2 Cadmium, Mercury and Zinc combination For Lamp 1; started at...

Mapping wavelength with the grating position In each of the frames the peaks mean position was noted along with its micrometer setting for the grating....

Mapping wavelength\grating\position on camera add term to fit function so %$f(m,\mu) \lambda {0} a {1}m b {1}\mu c {1}m\mu... $% plot histogram...

Data to be taken Take many frames with same exposure to see sperad of data, error estimate Take frames with different exposure times, for seeing how %$\sigma...

Observation 1 Time: 7:30pm Set camera cooler to 15 deg C Connected the spectrometer to the telescope. Aligned telescope with Vega by pointing...

Improving the fit to the line Initially a gaussian convoluted with a circular distribution was fitted to the spectral line, with the equations of: Gaussian...

Halogen Lamp Use the better fit for calibration of the wavelength and see how plot turns out Mapping The larger standard deviation of the residual plot...

Additional Data Taking Previously, plotted %$\sigma {\sigma}$% against exposure time for one spectral line from the Helium lamp Noticed this plot was not...

Fixing errors Found previously that errors in background of frame are not poisson wanted to investigate how points fluctuate in peaks as well as background...

Errors Pick just one point in the peak to see how it varies Plot both sigma per exposure time and sigma against exposure time see how sigma varies with...

Errors The root mean square was found for each pixel column across 10 frames, for each exposure. \begin{equation} N {\mathrm{rms}} \sqrt{\frac{N {0}^2 N {1}^...

Errors Take new data and try plotting rms vs average again Mapping Reducing %$\alpha$% reduces %$\gamma$% so related by constant %$\alpha \alpha 0 \gamma...

Further Data Taking Cooler temp 5 degrees 10 images at each exposure time Low mercury Took images in range 0 1s in 0.1s intervals...

Data Taking with Other Lamps Camera Setup camera temp 5 deg Focus distance 19.9mm Camera Angle 4.6mm Low Mercury...

Spectrometer Camera JosephBayley 09 Oct 2015

Errors Took 10 frames of one spectral line from Helium lamp at exposure times between 0 0.5s in 0.05s intervals. The root mean square was found for each pixel...

Errors Put the poisson error curve on the plot Look at the relative fluctuation compared to the total number in histogram where %$p i \frac{n i}{N...

Vega Fitting Set r as a fit parameter Gaussian: \begin{equation} f(y;\mu,\sigma) \frac{1}{\sqrt{2\pi} \sigma^2} e^{\frac{ (y \mu)^2}{2 \sigma^2}} \end...

Vega Lines Try to fit with a set value for the amplitude Test the values of the fit parameters Look up the Voigtian fitted parameters for Vega...

Vega Fitting Gaussian: \begin{equation} G(x;V) \frac{1}{\sqrt{2\pi \sigma^2}} e^{\frac{ (x \mu)^2}{2 \sigma^2}} \end{equation} Lorentz: \begin{equation...

Fitting For numerical way try doubling the x range look at running the fit for more iterations to get correct value wings have some other complicated structure...

Circle radius Found the radius of the circle by taking an average if many measured lines: Parameter Helium Cadmium(2.9) Cadmium (3.5) Cadmium(4.0)...

Additional Data Taking Wanted to see how RMS vs average plot varied with temperature Helium lamp, cooler 0 deg, micrometer (grating) setting at 5.0mm...

Fitting Gaussian: \begin{equation} G(x;\mu,v) \frac{1}{\sqrt{2\pi}V} e^{\frac{ (x \mu)^2}{2 V}} \end{equation} Lorentz: \begin{equation} L(x;\gamma)...

Fitting Check that the functions are normalised Try to find out why the errors were large see which of the spectral lines are towards the edge of the...

Errors Took a frame every minute to check when the lamp becomes stabilised. exposure, 0.1s Temp, 0deg Once the lamp was stabilised frames were taken...

Fitting Gaussian: \begin{equation} G(\lambda;\lambda 0,\sigma) \frac{1}{\sqrt{2\pi} \sigma^2} e^{\frac{ (\lambda \lambda 0)^2}{2 \sigma^2}} \end{equation}...

3C273 We initially took images of the quasar to locate it, the transmission grating was then places in front of the CCD to obtain its spectrum. As 3c273 is an...

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...

Major Project All of my MSci Major Project work can be found at the following link: https://twiki.ph.rhul.ac.uk/twiki/bin/view/Public/StewartBoogertSpectroscopy...

MSci Major Project Work Up to date work on MSci Major Project can be found at the following URL: https://twiki.ph.rhul.ac.uk/twiki/bin/view/Public/StewartBoogertSpectroscopy...

Spectrometer and Camera setup Here is a diagram to illustrate how the spectrometer is setup spectra setup: Light is passed through one end of the...

Spectrocopy Project The main aims of this project are to observe a star to obtain its spectrum, then analyse this to find where the lines come from and then determine...

Stellar Spectrocopy Project The main aims of this project are to observe a star to obtain its spectrum, then analyse this to find where the lines come from and then...

2015 Projects Photometry Spectroscopy 2016 Projects Photometry Spectroscopy 2017 Projects 2018 Projects Photometry 2019 Projects...

Number of topics: 49

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