"In the beginning, the universe was created. This made a lot of people very angry, and has been widely regarded as a bad idea."
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A short movie showing how the observed spectrum of star-forming galaxies (thick black line) changes as we observe it at higher and higher redshift. Redshift is denoted here in this movie as "z". Note how the break in the spectrum shifts to redder and redder wavelengths as a result of this redshifting effect. To be able to identify galaxies at the highest redshifts (and thus near the beginning of the universe), it is necessary to be able to measure the fluxes of sources at near-infrared wavelengths (>1000 nm). High-redshift galaxies are frequently found by noting a significant break in the spectrum as seen through a set of discrete filters (shown here in terms of their wavelength sensitivities as a set of colored lines).
Credit:Rychard Bouwens
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