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When the First Stars Formed

When the First Stars Formed. How did we get from the “Big Bang” to a sky full of galaxies?. NASA, ESA, S. Beckwith and the HUDF Team. Lincoln Greenhill Harvard-Smithsonian CfA Public lecture, U. Tas 05 Dec 8. Is this as far back in time as we can see ?. What came before these galaxies?.

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When the First Stars Formed

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  1. When the First Stars Formed How did we get from the “Big Bang” to a sky full of galaxies? NASA, ESA, S. Beckwith and the HUDF Team Lincoln Greenhill Harvard-Smithsonian CfA Public lecture, U. Tas 05 Dec 8

  2. Is this as far back in time as we can see? What came before these galaxies?

  3. Before the first galaxies Fireball of birth and a hot soup of radiation and matter

  4. Temperature History Radiation Temperature Matter z 104 103 Time 300,000 yr

  5. Temperature History Radiation Temperature Matter 103 K Hydrogren Recombination z 104 103 Time 300,000 yr

  6. Temperature History Radiation Temperature Matter 103 K Last scattering of radiation by matter Matter and primeval radiation go separate ways z 104 103 Time 300,000 yr

  7. Structure at Recombination DT/T~10-5 Very uniform! NASA/GSFC/WMAP Collab. Background microwave emission remnant

  8. Structure at Recombination NASA/GSFC/WMAP Collab. DT/T~10-5 A far cry from stars and galaxies Background microwave emission remnant

  9. Temperature History Radiation Temperature Matter 103 K The Dark Ages (a sea of H) z 104 103 0 yr Time 300,000 yr

  10. A Very Different Place when the First Stars… The Dark Ages First Luminous Objects z 103 101 6.2 0 yr 300,000 yr 109 yr Collapse of dark matter and cold Baryonic matter

  11. Ecology at Recombination Matter = 13% normal + 87% “dark” on avg. Most matter in the universe appears to be DARK, apparently interacting only via gravity (Zwicky c.1933) Dark/normal matter are intermingled. Collapse of dark matter structures carries along normal matter. Baryogenesis http://aether.lbl.gov/WWW/tour/elements/early/early_a.html

  12. Collapse of Dark Matter during Reionization (Springel et al. 2005)

  13. Collapse of baryonic matter into stars and galaxies z=20 Time Springel & Hernquist 2003

  14. (Gnedin et al.)

  15. Increasing transparency during reionization (Gnedin et al.)

  16. How Can We Study the EOR? • Radio imaging of the Hydrogen reservoir • The dominant component of the universe • Radiation not blocked by cosmic dust • Hydrogen has rest frequency of 1420 MHz • Mapping H in the nearby universe is routine. • • But at redshifts > 6 it appears at < 200 MHz • TV channels through 11 & FM radio • Trying to see stars from under a street lamp • What comes next? • Find radio quiet locations • Build new observatories: the Epoch of Experimentation

  17. Image courtesy of NRAO/AUI ; Yun, Ho, & Lo

  18. MILEURA

  19. A “traditional” radio observatory The Very Large Array New Mexico Operation 300 MHz- 50 GHz

  20. Innovation for work below 200 MHz… The Mileura Wide-field Array / Low Frequency Demonstrator

  21. “Mileura Wide-field Array Science and Technology Demonstrator,” a proposal to the NSF

  22. When all is said and done, will we find the Epoch of Reionization? Yes or no, it will be one of the great challenges of astronomy and an adventure. Illustrated “Gulliver’s Travels” c. 1930 Springel & Hernquist 2003

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