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17	How to Identify Lines Pick the two strongest lines you see and find their ratio (greater than 1). Because line spacing is “stretched” as lines are red-shifted, the line ratios remain a constant. Match your ratio to the emission-line ratios found in the line ratio data table. If no clear match is found, then pick some new lines and try to find a matching ratio.
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19	Using Graphical Analysis… We determine the wavelengths of the emission lines using the “examine” tool under the “Analyze” menu selection. Then line ratios are determined on the calculator. Compare line ratios with table to identify the 2 lines.
20	Determine the “z” Value Once these two lines are identified, then the redshift parameter “z” can be calculated as: 1 + z = l_rest/l_obs Once z is determined, it can be verified by checking the redshift of other known lines. l_rest = l_obs(1+z) Compare l_rest with known lines. If there are no other lines which verify z, then start over and try different emission line ratios.
21	Calculating Velocity
22	Calculating Distance Hubble’s Law comparing galaxy distances (Mpc) and recessional velocities (km/sec): Assuming the “empty universe” model, we can relate distance to redshift with this equation where H_o = 75 km/sec/Mpc:
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41	Analysis Generally, the luminosity of emission lines increases with the quasar’s red-shift (and therefore distance). Ly-a, C IV and C III] are well grouped in luminosity values with Ly-a being the most prominent at greatest red-shift values.
42	Considerations & Future Study The instrumental response limits the data to the visible, near UV and near IR. Further studies would be valuable to help identify the luminosity trends in the far IR. Possible student participation: Line identification (for remaining data) AGN vs. non-AGN identification Redshift, velocity, and distance calculations Flux and luminosity calculations Additional analysis of data for possible trends.