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2009: A Big Year for Science!. 200 years, Darwin’s birth: 12 Feb 1809 150 years: The Origin of the Species 400 years: Galileo’s telescope + birth of modern astronomy (and science): International Year of Astronomy (IYA) www.astronomy2009.org. Astronomers learn by looking.
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2009: A Big Year for Science! • 200 years, Darwin’s birth: 12 Feb 1809 • 150 years: The Origin of the Species • 400 years: Galileo’s telescope + birth of modern astronomy (and science): International Year of Astronomy (IYA) www.astronomy2009.org Brooks School
Astronomers learn by looking Brooks School
The Electromagnetic Spectrum & Great Observatories No longer operating 2008: Fermi Gamma Ray Telescope Brooks School
Chandra X-ray Observatory NASA’s X-ray Eye on the Universe Named for Chandrasekhar, Nobel Laureate Brooks School
Chandra Light Path: Grazing Incidence Mirrors Brooks School
Launch: 23 July 1999 Brooks School
Views from Shuttle: “Columbia” Brooks School
Chandra’s Orbit: 64 hours Brooks School
Chandra’s Orbit in Space 3-day period Earth/Moon/Chandra Orbit around Earth Brooks School
Where are Stars Born? Orion Nebula Optical X-ray Brooks School
What do we see in X-rays? • Hottest, most violent sources in the Universe • Into centers of dense regions, e.g. galactic centers, gas clouds • Complete picture needs observations at many wavelengths • Today: tour of source which emit X-rays Brooks School
What makes a Star Shine? • Star burns fuel in its core (fusion: H→Helium) • Initially fuel is H, star is on Main Sequence “Adult” (e.g. The Sun) • When H runs out, core heats up and He, burns: “Middle Age” (Giant star) • When He runs out, it burns heavier elements, e.g. Fe Brooks School
Death of a Star • When all fuel runs out, the core collapses • Outer regions of star explode outwards: Supernova • SN shine more brightly than a galaxy for a few hours/days Brooks School
SN1987A • D=150 kly, in LMC • Brightest SN in 400yrs • Star ~20 Msun • Chandra Monitoring: 1999→present • X-rays as SN blast wave encounters equatorial material • X-ray brightening at least 5-10 yrs more Brooks School
CHANDRA X-RAY OBSERVATORY Cas A: First Light 1 Msec Deep Image Brooks School
Cassiopeia A: Supernova Remnant Optical: stars + cool gas/dust X-ray: hot gas, stellar remnant Brooks School
Crab Nebula CHANDRA HST Brooks School
Actual Chandra First Light • Point Source to focus: Quasar PKS0637-75, z=0.5 • X-ray Jet visible: 5” long, 200,000 lyrs Brooks School
Synchrotron and Inverse Compton Radiation Brooks School
X-ray/Radio Jets in Active Galaxies M87 jet in X-ray, radio and optical D=15 Mpc Brooks School
AGN Outbursts and Feedback in Clusters MS0735: Radio(red) X-ray(blue) (600 000 ly) • X-rays → Gas in clusters: • Site of star-formation • Accretes onto AGN • Accretion: fuels AGN+feeds outbursts → radio/X-ray jet • Outburst heats + displaces gas → shocks (kpc) • Slows cooling + accretion • This Feedback regulates: • galaxy mass • star formation • AGN growth M87: nested shocks Brooks School
Dark Matter: Direct Visualization • Colliding Galaxy Clusters: • Chandra (pink) • HST,Magellan (white) • Dark Matter (blue, measured via gravitational lensing) • Interpretation: • Drag on gas • No drag on stars/dark matter • Gravity due to dark matter clearly separated from baryons (gas) Bullet cluster Brooks School
Bullet Cluster Animation Brooks School
NGC 6240: Galaxy with Double X-ray Core Brooks School
NGC 6240 Movie Brooks School
Cosmology: Structure of the Universe Distance Measurement Size of an object Brightness of an object • Luminosity, L • Flux, F=L/4πr2 • If know L, measure F and determine r • L determined from observations of many similar sources Star r F L Earth Brooks School
Cosmology with Chandra Observations of Clusters Optical/X-ray of Abell 85 Growth of Structure: Simulation Universe is expanding, distance related to velocity Clusters are too bright → Dark Energy Brooks School
Matter and Energy Content of the Universe Dark Energy: • Anti gravity • Consistent with energy in the vacuum • Non-zero cosmological constant in Einstein’s General Relativity OR • Einstein GR is wrong/needs updating Brooks School
A bit about me! • Dr. Belinda Wilkes, Professional Astrophysicist (Astronomer) • Smithsonian Astrophysical Observatory, Cambridge, MA • On contract to NASA to run Chandra X-ray Observatory (Hubble’s X-ray sister) • Assistant Director, Chandra X-ray Center • English, BSc (St. Andrews), PhD (Cambridge, UK) • In USA since 1982 • Charlotte Garcia’s Mother! Brooks School
Closing CHANDRA X-RAY OBSERVATORY http://chandra.harvard.edu Brooks School