Galaxy History – how we got here • Stars evolve, therefore so do galaxies • We parts of a rich history – they grow, starburst, acquire gas, lose gas, change chemistry, shut down starbirth, interact with central black holes • Contemporary hints – the galactic fossil record • Cosmic time machine – we can see their past! • We must be wide-ranging in space and energy • Tools: Hubble, Chandra, Spitzer, GALEX, ground-based telescopes – and brains
…so galaxies do too. Some clues are found in the contemporary fossil record.
…so galaxies do too. Some clues are found in the contemporary fossil record. Elliptical galaxy: only old stars, no cold gas to make more
…so galaxies do too. Some clues are found in the contemporary fossil record. Elliptical galaxy: only old stars, no cold gas to make more Spiral galaxy: all ages present, stars still formed in gas-rich disk
Waiting for the light – the Universe is a one-way time machine 2.6 seconds round trip
8 minutes 75 minutes
4.3 years 15,000 years
60 million years 2 billion years
Abell 2125-C153 A galaxy loses its gas
Across the spectrum - now FarIR MidIR nearIR opt UV farUV X-ray gamma GALEX INTEGRAL Spitzer FUSE WMAP Hubble Chandra Akari
A panchromatic view -spiral galaxy M81 ROSAT GALEX Kitt Peak Spitzer VLA
+ + + + + + San Pedro Martir 115° 27´49 W31° 02´39 N2,830 m
A sky survey for the new millennium • Potentially 4000+ objects per exposure • Uniquely wide field for 6.5-meter telescope • Uniquely wide slice of spectrum at once • Add time dimension to Sloan survey galaxies • Study internal galaxy structure • UA involvement in project planning – at the table pending fundraising!
Even very distant galaxies can often be mapped from the ground Kitt Peak/Hubble, optical NASA IR telescope, IR
Galaxy history • Downsizing (I love the crash of a theory…) • Central black holes are ubiquitous and may regulate surrounding starbirth • Large galaxies grow at the expense of dwarfs • Galaxies have long interacted with their surroundings – gas, other galaxies…
Looking forward to looking back • Chemistry of young galaxies • How did these enormous black holes grow? • What were the first stars like? • Why do some galaxies shut down star formation, and others host massive rapid bursts?