1. 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)
24 April 2009
Brooks School

2. Astronomers learn by looking
24 April 2009
Brooks School

3. The Electromagnetic Spectrum & Great Observatories
No longer operating
2008: Fermi Gamma Ray Telescope
24 April 2009
Brooks School

4. Chandra X-ray Observatory
NASA’s X-ray Eye on the Universe
Named for Chandrasekhar, Nobel Laureate
24 April 2009
Brooks School

5. Chandra Light Path: Grazing Incidence Mirrors
24 April 2009
Brooks School

6. Launch: 23 July 1999
24 April 2009
Brooks School

7. Views from Shuttle: “Columbia”
Orbit 8 miles too low, major last-minute re-calculations of how to release it. Release ASAP because of the solid rocket booster which took it into its orbit. Katie Kolman, Mission Specialist
24 April 2009
Brooks School

8. Chandra’s Orbit: 64 hours
24 April 2009
Brooks School

9. Chandra’s Orbit in Space
3-day period
Orbit around Earth
Earth/Moon/Chandra
24 April 2009
Brooks School

10. Where are Stars Born? Orion Nebula Optical X-ray 24 April 2009
Brooks School

11. 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
24 April 2009
Brooks School

12. 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
24 April 2009
Brooks School

13. 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
24 April 2009
Brooks School

14. 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
1.2”*1.6” is size of X-ray disk
24 April 2009
Brooks School

15. Cas A: First Light CHANDRA X-RAY OBSERVATORY 1 Msec Deep Image
24 April 2009
Brooks School

16. Cassiopeia A: Supernova Remnant
Optical: stars + cool gas/dust
X-ray: hot gas, stellar remnant
Look up density analogy for NS
24 April 2009
Brooks School

17. Crab Nebula
CHANDRA
HST
24 April 2009
Brooks School

18. Actual Chandra First Light
Point Source to focus: Quasar PKS , z=0.5
X-ray Jet visible: 5” long, 200,000 lyrs
24 April 2009
Brooks School

19. Synchrotron and Inverse Compton Radiation
24 April 2009
Brooks School

20. X-ray/Radio Jets in Active Galaxies
M87 jet in X-ray, radio and optical
D=15 Mpc
24 April 2009
Brooks School

21. AGN Outbursts and Feedback in Clusters
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
MS0735: Radio(red) X-ray(blue)
( ly)
M87: nested shocks
24 April 2009
Brooks School

22. 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
24 April 2009
Brooks School

23. Bullet Cluster Animation
24 April 2009
Brooks School

24. NGC 6240: Galaxy with Double X-ray Core
24 April 2009
Brooks School

25. NGC 6240 Movie
24 April 2009
Brooks School

26. 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
24 April 2009
Brooks School

27. 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
24 April 2009
Brooks School

28. 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
24 April 2009
Brooks School

29. 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!
24 April 2009
Brooks School

30. CHANDRA X-RAY OBSERVATORY
Closing
CHANDRA X-RAY OBSERVATORY
24 April 2009
Brooks School