Transcript telescopes
The tools Hot question of Galileo’s time • what’s at the centre: earth or sun? Sun-centered universe Galileo’s observations. 1. The Moon’s surface Moon not a perfect “heavenly body” Sun-centered universe Galileo’s observations. 2. Jupiter’s moons Jupiter has moons! > there are things that do not orbit the Earth! Sun-centered universe Galileo’s observations. 3. Phases of Venus Venus has phases, just like the Moon Attributed them to Venus’ motion around the Sun Copernicus is right! Earth is not at the centre! Hot questions of recent time • how do stars work? • how are chemical elements made? • how big is the universe? • what are “spiral nebulae”? • what are quasars? • are there planets around other stars? Better tools got us the answers Hot questions of today and tomorrow 1. how do planets form? 2. how do stars form? 3. how do galaxies form? 4. what were the first objects to form after the Big Bang? • To address these questions, we need great tools • What makes a great tool? Three things that count 1. sharpness of image •resolve structure - get into the details 2. wavelength coverage •go after different physical processes in the same object 3. ability to collect lots of light •go after faint objects •lots of detail on brighter objects from the ground from space Three things that count 1. sharpness of image •resolve structure - get into the details 2. wavelength coverage •go after different physical processes in the same object 3. ability to collect lots of light •go after faint objects •lots of detail on brighter objects M31 CO and optical M81: starlight & dust Three things that count 1. sharpness of image •resolve structure - get into the details 2. wavelength coverage •go after different physical processes in the same object 3. ability to collect lots of light •go after faint objects •lots of detail on brighter objects Bigger is better 5mm diameter 10m diameter The eye vs Keck eye Keck advantage photons/sec entering “instrument” : 4,000,000 x π(5/2 mm)2 of these, actually detected: 90 x ~1% ~90% < 1 sec >1 hr persistence (Integration time): 3600 x bottom line: π(10/2 m)2 ~1.3x10 12 x How do we go about it? 1. size 2. location, location location Bigger is better 5mm diameter 10m diameter How do we go about it? 1. size 2. location, location location Location, location, location •important for sharpness of image •clarity of atmoshpere (“seeing”) •or no atmosphere at all •ability to detect different wavelengths •Earth’s atmosphere absorbs light (esp. bad at IR) •so... get above the atmoshpere from the ground from space Hot questions of today and tomorrow 1. how do planets form? 2. how do stars form? 3. how do galaxies form? 4. when did the first structures (galaxies, stars...) form in the universe? The future (A Canadian perspective) Three world-class telescopes for Canada • • • ALMA (2010) JWST (2014) TMT (2018 ? ) ALMA (Atacama Large Millimetre Array) radio interferometer consisting of 64 12m antennas ALMA (Atacama Large Millimetre Array) • • at 5000m elevation in the Atacama desert (Chile) location minimizes water vapour in the atmosphere ALMA (Atacama Large Millimetre Array) • Capabilities: • star formation in the early Universe: • • heat emission from dust in distant galaxies • • very high spatial resolution = study internal structures molecular (cold) gas in distant galaxies large collecting area = high sensitivity JWST (James Webb Space Telescope) Next generation space telescope (successor to Hubble with a 6.5m segmented mirror 2.8m diameter 6.5m (equivalent) diameter JWST (James Webb Space Telescope) • Capabilities: • • • infrared (heat) observations from space very high spatial resolution: • • study structural details of distant galaxies search for planets around other stars large collecting area = very sensitive TMT (Thirty Meter Telescope) Extremely large optical telescope with adaptive optics TMT(Thirty Meter Telescope) • • • 30-m diameter (duh!) 3x bigger diameter than Keck => 9 times more collecting area Capabilities: • • • huge mirror: extreme light-gathering power adaptive optics: resolve very fine details or small separations extremely complementary to JWST Three world-class telescopes for Canada • ALMA (2010) • • JWST (2014) TMT (2018 ? )