Square Kilometre Array Science Stephen Fine SKA Fellow University of the Western Cape

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?

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 ( )

Telescopes as time machines Speed of light: 299,792 km/s You see this slide ~ seconds (30 nanoseconds) in the past. Astronomers like distances measured in lightyears 1 ly = 9,460,000,000,000 km

Telescopes as time machines Proxima centauri 4.24 ly

Telescopes as time machines Proxima centauri 4.24 ly

Telescopes as time machines Eta Carina ly

Telescopes as time machines Andromeda galaxy 2.2 Mly

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

Back to galaxy evolution In the nearby Universe we have a fairly good understanding of the demographics of galaxies. 0.4 billion years

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

Galaxy evolution With the largest telescopes we can find massive galaxies when the Universe was ~1/10 th its current age billion years 1 billion years after BB

Galaxy evolution We know that galaxies had not started forming until at least 0.2 billion years after the Big Bang billion years 0.2 billion years after BB

The state of the art No galaxies Some massive galaxies formed Limit of current large galaxy surveys Limit of current galaxy mass surveys

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

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

SETI with the SKA

Project Cyclops

Remind you of anything?

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)

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.

Final comments