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Dark Ages of Astronomy (Dark to Light)

Dark Ages of Astronomy (Dark to Light). Dark Ages. z =0. z =5.8. z =1000. SDSS Reionization Studies. SDSS telescope at Apache Point. End of Reionization - SDSS Quasars - Fan et al. 2006. Possible Causes of Reionization. Dark Matter-Driven Gravitational Collapse Hydrodynamic Interactions

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Dark Ages of Astronomy (Dark to Light)

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  1. Dark Ages of Astronomy(Dark to Light) Dark Ages z=0 z=5.8 z=1000

  2. SDSS Reionization Studies SDSS telescope at Apache Point End of Reionization - SDSS Quasars - Fan et al. 2006

  3. Possible Causes of Reionization Dark Matter-Driven Gravitational Collapse Hydrodynamic Interactions Atomic and Molecular Cooling Star Formation Stellar Death Synthesis and Dispersal of Metallic Elements Birth & Feeding of the 1st Supermassive BHs {

  4. Cosmic Reionization Razoumov et al. 2002

  5. Movie of a Typical Reionization Model Overdense to Underdense: yellow, green, light blue, dark blue Black regions are neutral. 100 Mpc Time in movie is linear in physical time.

  6. GRB 050904 at z=6.295 • Observed damping wing of Ly-alpha (Miralda-Escudé 1998) • Host and IGM absorption have different profiles (-1 vs. -2) • GRB 050904 dominated by host absorption - DLA with log NHI = 21.6 • Upper limit on IGM neutral fraction: xHI < 0.6 (90% c.l.) • First cosmological constraint from a GRB observation • Taken 3.4 days after the burst xHI Totani et al. 2006

  7. Damping Wing Lyα Absorption Lyα Cross Section: Absorption profile: Miralda-Escude (1998)

  8. GRB Cosmology • GRBs only require a single massive star • Theoretical expectations of a maximum redshift z>10 • Afterglows bright enough, for a brief time, to enable cosmological measurements (GRB 050904) • Possibility to harvest more such bursts than Swift does by pursuing a targeted strategy: • Softer band for prompt emission • Infrared telescope for follow-up, with low resolution spectroscopy • Aiming to provide a redshifts in real time

  9. Reionization Questions • How does the cosmic SFR evolve beyond z=5? • Did high-mass stars play a dominant role in reionization? • How did the metal enrichment of star-forming regions progress? • What was the contribution of quasars to reionization? • When were the first quasars born? • How fast did quasars grow? • How did reionization proceed over 6<z<10?

  10. Investment into Reionization SDSS JANUS JWST ELTs Wavelength 2005 2010 2015 2020 WMAP ALMA SKA LOFAR+MWA

  11. JANUS Objectives Science Objectives: (1) Measure SFR 5<z<12 by discovering high-z GRBs & afterglows; (2) Enumerate brightest quasars over 6<z<10 & measure reionization contribution; (3) Enable detailed studies of the reionization history & metal enrichment in the early Universe; (4) Provide 3D positions of high-z star-forming galaxies & SMBHs to next-generation observatories

  12. JANUS Mission Concept Survey Mode Discovery Mode Via TDRSS

  13. JANUS Observatory X-Ray Flash Monitor (XRFM): Coded Mask, 1-20 keV, 4 sr FoV Near-IR Telescope (NIRT): 50 cm, 0.7-1.7 μm, J = 19.6, 1296 arcmin2 FoV Detects & localizes high-z GRBs Low-resolution spectroscopy of high-z GRBs & quasars HE Monitoring Instrument (HEMI): non-imaging , 0.02-1.5 MeV, 6 sr FoV γ-ray spectroscopy

  14. JANUS GRB Science

  15. GRB Detections w/ JANUS Bromm & Loeb (2006)

  16. JANUS Survey Science • Measure the ionizing flux of quasars over 6 < z < 10 by discovering and observing the brightest high-redshift quasars • 20,000 deg2 survey • 300 z> 6 quasars • Maximum z≈10 • Ionizing flux of each quasar measured directly from continuum

  17. JANUS Quasar Science

  18. Quasar Detections w/ JANUS

  19. JANUS Science for “Free” • Brown Dwarf studies • GRB-SNe connection • 3-11/year • X-ray All-Sky Monitor • Super-flares from solar-type stars • Supergiant fast X-ray transients • Tidal Disruption Events

  20. JANUS Status • One of six missions selected for a Phase A Concept Study (May-2008) • Concept Study Report due (Dec-2008) • Two of six missions selected by NASA for build phase (May-2009) • Phase B begins (Jun-2009) • Launch (~2013)

  21. Janus was the god of gates, doors, doorways, beginnings, and endings. Janus was frequently used to symbolize change and transitions such as the progression of future to past, of one condition to another, of one vision to another, and of one universe to another. He was also known as the figure representing time because he could see into the past with one face and into the future with the other. Janus is also know as “custodian of the universe” and was a deity of beginnings.

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