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Published byElfreda Hutchinson Modified over 9 years ago
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Square Kilometre Array Science Stephen Fine SKA Fellow University of the Western Cape
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SKA Science goals Cosmology + Galaxy evolution Testing general relativity: gravity waves Magnetic fields in the Universe Exoplanets and SETI The first light in the Universe…….EVER?
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Cosmology + Galaxy evolution `If you want to make an apple pie from scratch, you must first create the Universe.’ `You have to know the past to understand the present.’ Carl Sagan (1935-1996)
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Telescopes as time machines Speed of light: 299,792 km/s You see this slide ~ 0.00000003 seconds (30 nanoseconds) in the past. Astronomers like distances measured in lightyears 1 ly = 9,460,000,000,000 km
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Telescopes as time machines Proxima centauri 4.24 ly
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Telescopes as time machines Proxima centauri 4.24 ly
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Telescopes as time machines Eta Carina 7500-8000 ly
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Telescopes as time machines Andromeda galaxy 2.2 Mly
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Cosmic timeline Earth Distance = 0 ly Age = 13.7 billion years Big Bang Distance = 13.7 billion ly Age = 0 Between here is the whole history of cosmic evolution
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Back to galaxy evolution In the nearby Universe we have a fairly good understanding of the demographics of galaxies. 0.4 billion years
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Galaxy evolution Stepping out we have optical surveys that can find large numbers of galaxies when the universe was ~4/5 th its current age. 2.5 billion years
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Galaxy evolution With the largest telescopes we can find massive galaxies when the Universe was ~1/10 th its current age. 12.7 billion years 1 billion years after BB
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Galaxy evolution We know that galaxies had not started forming until at least 0.2 billion years after the Big Bang. 13.5 billion years 0.2 billion years after BB
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The state of the art No galaxies Some massive galaxies formed Limit of current large galaxy surveys Limit of current galaxy mass surveys
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Enter the SKA No galaxies Some massive galaxies formed Limit of current large galaxy surveys Limit of current galaxy mass surveys A mass survey over half the observable Universe Will detect `typical’ Milky Way type objects as they are first forming
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Enter the SKA No galaxies Some massive galaxies formed Limit of current large galaxy surveys Limit of current galaxy mass surveys A mass survey over half the observable Universe Will detect `typical’ Milky Way type objects as they are first forming
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SETI with the SKA
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Project Cyclops
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Remind you of anything?
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Some estimates for SKA SETI Terrestrial TV/radio Could be observed from ~75 ly ~2500 stars in that volume ~250 are sun like. – (Most others too faint)
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Some estimates for SKA SETI Radar (especially military) Could be observed from a few hundred ly ~10000 stars in that volume ~1000 are sun like.
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Final comments
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