1. Extremely Large Telescopes and the Epoch of Reionization Xiaohui Fan(Arizona) with help from Pat McCarthy and GMT Science Working Group July 11, 2008, KIAA-PKU

2. European ELT Program OWL - 100 meter 14,000 tons 3048 segments 5 mirror system Euro 50m 3,500 tons 618 segments 3 mirror system

3. European ELT Program 42m baseline 5 mirror system 850M€ budget (~ $1.1B) First light 2017+

4. Thirty Meter Telescope

5. TMT 30m Aperture 738 segments 3 mirror f/1 primary f/15 foci First light ~2018 Site: MK/Chile Caltech Canada U. California

6. The Giant Magellan Telescope Project

8. Giant Magellan Telescope Project

9. GMT Partners Astronomy Australia Limited Australian National University Carnegie Institution of Washington Harvard University Smithsonian Institution Texas A&M University U. of Arizona U. of Texas at Austin Joining: Korea Astronomy & Space Science Institute Site: Las Campanas, Chile First light ~2018

10. Telescope Concept Seven x 1.1m segmented secondary mirror (3.2 m Φ ) Seven x 8.4 m segmented borosilicate primary mirror Alt-az mount Laser housing Pier Telescope stats Height: 38.7 meters 1,125 metric tons Lowest Mode: 4.5 Hz (4.3 Hz with pier)

11. M1 Fold sphere & GMT1 Jan 2008 3.8 m Fold sphere GMT1 GMT1 Completion April 2009

12. GMT & LBT Comparison

13. Las Campanas Observatory Magellan (Manqui)Campanas Pk. Alcaino Pk. Ridge (Manquis)

14. Cost Scaling Laws ELTs ~ D 2.7 ELT projects must break past scaling laws to be affordable!

15. GMT Science Case Planets and Their Formation Stellar Populations and Chemical Evolution Assembly of Galaxies Black Holes in the Universe The Accelerating Universe First Light and Reionization of the Universe Science case: www.gmto.org

16. Probing Reionization History Fan, Carilli & Keating 2006

17. Relevant Instrumentation IGM and Reionization studies need high resolution spectroscopy, multiplexed survey spectroscopy and near-IR AO-fed IFUs All three ELT projects are looking at MOS systems in the visible and near-IR and echelle spectrographs and IFUs in the near-IR with a view towards early universe studies.

18. NIRMOS - An Example near-IR MOS Wavelength range: 0.85 – 2.5 μm Imaging Mode: –7 x 7 arcmin field of view –0.067 arcsec/pixel –6kx6k detector Spectroscopy Mode: –Multi-slits: 140 x 3 arcsec long, full wavelength coverage –5 x 7 arcmin field of view –R ~ 3000 with 0.5 arcsec slits Augmented by GLAO

19. GMACS & NIRMOS on the GMT

20. Wavelength (  m) 5  1 hr Sensitivity (  Jy) 3 2 1 0 -2 -3 0.30.51.02.03.05.01020 Discovery Space 24 26 28 30 22 20 m AB - - Adaptive Optics Seeing Limited 8m limit GMT limit Gain Spectroscopy

21. Reionization Probes with the ELTs -Gunn-Peterson effect -“Dark” GRBs ? -Evolution of Ly  luminosity density and spatial distribution of LAEs -HeII emission from z>8 Galaxies -Ly  florescence from boundary regions -Abundance in extremely metal poor stars How can ELTs explore the end of the Dark Ages?

23. Accelerated Evolution at z>5.7 Optical depth evolution accelerated –z<5.7:  ~ (1+z) 4.5 –z>5.7:  ~ (1+z) >11 –End of reionization? Evolution of neutral fraction –f HI > 10 -3 - 10 -2 at z=6 –Order of magnitude increase from z~5 –G-P absorption saturates; needs more sensitive tests (1+z) 4.5 (1+z) 11 XF et al. 2006

24. Reionization History X. Fan Z=9.4 QSO Magellan 8hrs GMT 8hrs

25. Evolution of IGM Metals Early Enrichment of the IGM by First stars –Lack of evolution in metal line density up to z~6 OI Forest (Oh 2002) –OI and H have almost identical ionization potentials –In charge exchange equilibrium with H but much lower abundance –Fluctuating OI forest during neutral era to probe ionization topology and metal pollution in the IGM OI system at z=6.26 Becker et al. 2006 Ryan-Weber et al. Evolution of CIV systems

26. Iye et al. 2006 Kashikawa et al. 2006 Ota et al. 2007 Ly  Galaxy LF at z>6 Neutral IGM has extended GP damping wing  attenuates Ly  emission line New Subaru results –Declining density at z~6-7 (2-3  result) –Reionization not completed by z~6.5 –f HI ~ 0.3 - 0.6 at z~7 –Overlapping at z=6-7? –cf. Malhotra & Rhoads, Hu et al.: lack of evolution in Ly  galaxy density

27. Reionization Topology with Ly  Emitters Ly  emitter could provide sensitive probe to reionization history, especially during overlapping –Evolution of LF (constrain f HI ) –Clustering –genus numbers Distribution of Ly  emitters over 3’x3’ FOV McQuinn et al. Angular correlation of Ly  emitters Neutral  Ionized

28. Use Case: Ly  Luminosity Function at z ~ 6 500 km/s FWHM W = 100Å 30hr integration with GMACS using 0.5” slits in 0.5” seeing 30% throughput Gemini sky spectrum Nod & Shuffle sky rejection R = 5000 rebinned to R = 1200, Gaussian smoothing

29. Mock Ly  Luminosity Function at z ~ 6 with GMT How do we extend this to z > 8?

30. Ly  Spectroscopy in the Near-IR Ly  at z = 8.7 in the J-band NIRMOS Properties with current Near-IR detectors 200 km/sec line widths 25 hour exposures 7 x 7 field of view Photons/sec/cm 2 ~ IOK-1

31. Ly  Spectroscopy in the Near-IR NIRMOS Properties with OH Suppression and low-noise Near-IR detectors 200 km/sec line widths 25 hour exposures 7 x 7 field of view With OH suppression

32. Ly  Spectroscopy in the Near-IR NIRMOS Properties with OH Suppression and low-noise Near-IR detectors 200 km/sec line widths 25 hour exposures 7 x 7 field of view With OH suppression

33. Ly  Emitter Surveys in ELT/JWST Era Interpretation of Ly  emitters alone is highly model dependent: –Evolution of continuum LF –Uncertainties in Ly  radiative transfer –Intrinsic clustering of galaxies etc. Requires surveys of continuum and SF selected samples intrinsic observed · Ly  selected  continuum selected Rhoads 2007

34. Structure at z ~ 10 Numerical simulation of gas cooling at z = 10 Dave’, Katz & Weinberg

35. Ly alpha image with GMT GLAO R=3000 filter 20% escape fraction 8 hour exposure Laser Tomography AO Ly  HeII 1640 Structure at z ~ 10 Very top-heavy IMF!

36. ELT SCIENCE: CONTEXT & SYNERGY JWST ALMA LSST SKA Broad Synergy Across Wavelength, Spatial and Time Domains Magellan Physical Diagnostics Deep/Wide Surveys High-resolution imaging High SNR & Res. Spectroscopy

37. Reionization Probes: ELT vs. JWST ELT: –Narrow-band imaging in the near-IR (YJH bands): LAE surveys –High resolution IR spectroscopy (R>3000): first metals in the IGM –High resolution optical spectroscopy: first stars –OH suppression and Ground-Layer AO crucial JWST: –Continuum-based surveys: reionization sources –Tunable filter narrow-band surveys (>1.5 micron): LAEs –Low-resolution spectroscopy: high-z quasars and GRBs

38. Probing Reionization History JWST, ELT 21cm, GRB, ALMA Fan, Carilli, Keating 2006