Have you ever wondered how telescopes collect the light of the stars to be later analyzed by the astronomers? This new AAO video, entitled Rainbow Fingerprints shows how this is done at the Anglo-Australian Telescope (AAT). The video was produced by AAO Astronomer and Outreach Officer Amanda Bauer, and I have collaborated providing not only the sequences of the AAT outside and inside the dome (which were extracted from my timelapse A 2dF night at the AAT) but also providing comments during the production process.
Video “Rainbow Fingerprints” showing how the light of distant galaxies in collected by the Anglo-Australian Telescope and directed to the AAOmega spectrograph using optical fibres. More information in the AAO webpage Rainbow Fingerprints. Credit: AAO, movie produced by Amanda Bauer (AAO).
The light coming from distant galaxies is first collected using the primary mirror of the telescope, which has a diameter of 4 meters, and then it is sent using optical fibres (the 2dF system) to a dark room where the AAOmega spectrograph is located. This spectrograph, which is a series of special optics, separates the light into its rainbow spectrum, in a similar way a prism separates white light into a rainbow. The separated light is later focussed onto the CCD detector. Finally the video reveals the science quality spectra for two different types of galaxies, one spiral (top panel) and one elliptical (bottom panel), using actual data obtained with the AAT and the AAOmega spectrograph. The information codified in the rainbow fingerprint identifies each galaxy unambiguously: distance, star formation history, chemical composition, age, physical properties as the temperature or the density of the diffuse gas, and many more.
I hope you enjoy it!