CSI 661 / ASTR 530 Spring 2011 Jie Zhang

1. Astrophysics The Prelude Jan. 26, 2011 CSI 661 / ASTR 530 Spring 2011 Jie Zhang

2. The Big Bang http://rampant-mac.com/dp_07/Big-Bang-Theory_alt2_1920.jpg

3. History of the Universe http://www.negotiationlawblog.com/Big%20Bang.jpg

4. Physical Forces Depending on temperature (T) and density (ρ)

5. Inflation • Inflation occurs at 10-35 second after the Big Bang when temperature of universe dropped to 1027 K; at this temperature, strong force became distinct from the electromagnetic-weak force • Before the inflation, the space is “empty”, filled with only virtual particles dictated by quantum mechanics • Matter and energy of the universe is created during the inflation • Just after the inflationary epoch, the universe was filled with particles, antiparticles and energetic gamma-ray photons

6. Create Radiation • At t=10-6 second, the temperature in the universe dropped to the threshold temperature of 1013 K, at which the photons can not produce proton and anti-proton pairs (and neutron and anti-neutron pairs) • At about t = 1 second, temperature fell below 6 X 109 K, electrons and positions annihilated to form low energy gamma-ray photons that can not reverse the process • As a result, matter and anti-matter content decreased, and radiation content increased • From 1 second to 380,000 years, the universe is dominated by the radiation (so called primordial fireball) derived from the annihilation of particles and antiparticles created early by the inflation

7. Create Ordinary Matter • If there had been perfect symmetry between particles and antiparticles, every particles would have been annihilated, leaving no matter at all in the universe • There are 109 photons in the microwave background for each proton/neutron in the universe • Therefore, there is a slight but important asymmetry between matter and antimatter • Right after the inflation, for every 109 antiprotons, there must have been 109 plus one ordinary protons, leaving one surviving after annihilation

8. Relics of primordial fireball • When the universe was 3 minutes older, the temperature was low enough to pass the deuterium (2H, one proton + one neutron) bottleneck to further produce helium • At 15 minutes, the temperature of the universe is too low for any further nucleosynthesis • Therefore, the relics of primordial fireball are hydrogen, helium (1 helium out of every 10 protons), and photons (1 billion photons for every proton) • Heavier elements are formed later in the stars, not in the early universe

9. The State of the Universe • Age: 13.7 billion years • Composition: 73% dark energy, 23% dark matter, 4% ordinary matter

10. Galaxies • This map shows 1.6 million galaxies from the 2MASS (Two-Micron All-Sky Survey) survey • Supercluster of Galaxies lie along filaments

11. Galaxies

12. Our Galaxies We are located in the middle of the Milky Way Galaxy 28,000 light years from the center One of 200 billion stars in our Galaxy

13. Star Formation: Nebula • Interstellar gas and dust pervade the Galaxy • Nebula: a cloud of concentrated interstellar gas and dust; 104 to 109 particles per cubic centimeter

14. Star Formation: Protostar • Protostar: the clump formed from dense and cold nebula under gravitational contraction • The protostar contracts, because the pressure inside is too low to support all the mass. • As a protostar grows by the gravitational accretion of gases, Kelvin-Helmholtz contraction causes it to heat and begin glowing • When its core temperatures become high enough to ignite steady hydrogen burning, it becomes a main sequence star

15. Star Formation: Protostar

16. Star Formation • A protostar’s relatively low temperature and high luminosity place it in the upper right region on an H-R diagram

17. Stars

18. The Sun Solar wind creates a big teardrop-shaped heliosphere around the solar system, by interacting with the interstellar wind

19. The Earth The Earth 3rd planet from the Sun 1 AU = 150 million km Travel time: By light -- 8 minutes By Solar Wind-- ~ 100 hrs

20. The Sun-Earth Connection Credit: NASA

21. Space Weather: the Process It starts from an eruption from the Sun. Prediction depends on how it propagates

22. Space Weather: effects Aurora; Geomagnetic Storm From Space

23. Space Weather: effects Adverse effects Power failure due to March 1989 storm Damaged transformer

24. Space Weather: effects On Human Space Exploration On crew and passengers of polar-route airplanes

25. Space Weather: effects On Satellite Operation

26. Space Weather: effects On Communication and Navigation

27. Components of Sun-Earth The driver of Space Weather Planet Coronal mass ejections

28. Components of Sun-Earth Heliosphere: solar wind Planet Spiral solar wind magnetic field: radial motion of solar wind combined with Sun’s rotation Sprinkler Analogy

29. Components of Sun-Earth Magnetosphere Planet A comet-shaped region around the Earth

30. Components of Sun-Earth Magnetosphere Planet Electric Currents in Magneto- sphere

31. Components of Sun-Earth Magnetosphere Planet Energetic particles in Van Allen radiation belt

32. Components of Sun-Earth Ionosphere Planet Density fluctuation affects radio wave reflection and transmission

33. Re-focus on Physics Hinode

34. Re-focus on Physics STEREO

35. Re-focus on Physics SDO

36. The End