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Progress of the Wide-Field Deep Surveys for Galaxies at z=3-9

Progress of the Wide-Field Deep Surveys for Galaxies at z=3-9. Masami Ouchi (STScI). Overview. Introduction Recent results of our z=3-7 LyαEmitter studies On-going Wide-Field NIR Search for z=7-9 objects Summary. Why are Studies of z=3-9 Galaxies Important?. (2) Reionization :

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Progress of the Wide-Field Deep Surveys for Galaxies at z=3-9

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  1. Progress of the Wide-Field Deep Surveys for Galaxies at z=3-9 Masami Ouchi (STScI)

  2. Overview • Introduction • Recent results of our z=3-7 LyαEmitter studies • On-going Wide-Field NIR Search for z=7-9 objects • Summary

  3. Why are Studies of z=3-9 Galaxies Important? (2) Reionization: z~6:Epoch of transition (1) Galaxy formation: z>~5 emergence of galaxy halos galaxy cluster Evolution of neutral fraction of IGM (Fan et al. 2006) Num. density evolution of halos predicted with the ΛCDM model of Sheth&Tormen1999

  4. Galaxies (black dots) and cosmic HII region (orange) from simulations (Iliev et al. 2006) Reionization & Galaxies Lyα line profiles of galaxies at z=8 Intrinsic Lyα absorbed Dijkstra et al. (2007) Lyα emitting galaxies place constraints on reionization properties

  5. (1) Lyα Emitters (LAEs) Lyα Redshift • Identify a redshifted Lyα emission line with a narrow band (NB) • Lyα emitting (~dust-poor) star-forming galaxies. Kodaira et al. (2003)

  6. (2) Dropout galaxies • Identify a redshifted continuum break (Ly break+GP trough) • UV bright star-forming galaxies Redshift Stanway et al. (2005)

  7. SDF(0.2 deg2;i=27.4 ) [13h24m39s ,+27o29’26”] 1 pointing of Suprime-Cam SXDF(1.3 deg2;i=27.0) [2h18m00s ,-5o00’00”] 5 pointings of Suprime-Cam 141h-1 Mpc XMM-Newton 0.5-2 (Ueda+07) VLA 1.4 GHz (Simpson+06) X-ray to Radio • X-ray(XMM),UV(GALEX), NIR(UKIRT),IR(Spitzer),Sub-mm(SCUBA+BLAST), Radio(VLA,GMRT)

  8. High-z Galaxy Samples • Lyα Emitter (LAE) SDF SXDF • z=3.1: - 356(41) (NB503<25.3; BVNB 2 colors) • z=3.7: - 101(29) (NB570<24.7; BVNB 2 colors) • z=4.9: 87(5) - (NB711<26.0; RiNB 2 colors) • z=5.7: 89(27) 401(17) (NB816<26.0; RiNB 2 colors+ no flux in BV) • z=6.6: 58(19) >106 (NB921<26.0; izNB 2 colors+ no flux in BVR) • z=7.0: 2(1) - (NB973<25; zNB 2 colors+ no flux in BVR) Number in () is the one of spectroscopically identified objects • Thanks to the deep & wide field imaging data, we have obtained ~1,000 LAEs at z=3-7 (c.f. x10 larger number of LAEs than previous studies) NB503 NB570 NB711 NB816 NB921

  9. Examples of our LAEs • Star-forming galaxies (1-10 Mo/yr) • and possibly some cooling clouds and fluorescence (Juna Kollmeier’s talk) • AGN • VLA 1.4GHz (>20μJy) • XMM (≳5e-16 erg/s/cm2) • ~3 (radio) and 2(X-ray)/356 sources at z~3 • ~1(radio) and 2 (X-ray)/101 sources at z~4 • 0 radio/X-ray detection at z>5.7 →AGN : ~1/50 of all LAEs z=5.7 LAEs (Ouchi et al. 2005) LAE with a radio contour radio loud AGN z=3.123, f1.4=108±18μJy (Courtesy: Simpson)

  10. z=3 Evolution of LyαLuminosity Function • Observed LF→no evol. but fLyαabsorbed by IGM • intrinsic LF→ likely evolved • Contrary to UV continuum LF of dropout galaxies (e.g. Lehnert+03, Ouchi+04,Shimasaku+05,Bouwens+06+07) • Numer density of intrinsically bright LAEs increases from z=3.1 to 5.7 • emergence of different Lyα population (incl. PopIII, cooling clouds and/or dust poor) at higher redshifts?? z=3 Solid: Obeserved LF Dash: Intrinsic LF z=3 z=5.7 Ouchi et al. in prep

  11. Discovery of z=6.96 LAE in SDF Nature, Sep 14, 2006 • Not only the record break, but a scientific value. Iye et al., 2006, Nature, 443, 186

  12. z=5.7 At higher redshit: Lyα Luminosity func. • Observed Lyα LF → Num. dens. of bright LAE decreases from z=5.7 up to 7.0. (c.f. no evol. from z=3-5.7) • Evolution of IGM neutral fraction? (Kashikawa+06,Iye+06) and/or • Galaxy evolution? (Dijikstra+06) →Only study of LF cannot resolve the problem of reionization • Other physical properties for z=6-7 LAEs?? →HST/Spitzer coordinated observations in 2007-2008 (Egami et al.) z=5.7 z=5.7

  13. ---Beyond z=7---Our On-going Wide-Field Search

  14. Wide-field Search for z>7 Dropouts and LAEs • One (to 4) candidates of z=7-8 faint dropouts are identified in the HUDF. Deep search (J~27) in area (~20arcmin2; Bouwens & Illingworth 2006) . • Very faint “candidates” are found by gravitational lens studies (Richard+06, Stark+07). • No intrinsically-bright candidates of z>7 dropouts/LAEs are found by current searches. It cannot give a constraint on LF. Moreover, no spec conf . →A wide-field search is needed!! ? Bouwens & Illingworth (2006)

  15. Wide-field MOIRCS search in the GOODS • MOIRCS: wide-field NIR camera of Subaru (FoV=28arcmin2) • GOODS-N field (~140 arcmin^2) • Ultra-deep field with 1 FoV (30 hrs each for J and Ks) = x7 FIRES (Labbe et al. 2003) • Deep field with 3 FoVs(5 hrs each for J and Ks) =slightly deeper than ISSAC GOODS-S • In 2006-2008 (in total ~35 nights are allocated: Ichikawa/Tokoku,Ouchi et al.). • See Kajisawa et al. 2006, Ichikawa et al. 2007 for deep images of 2006 run. MOIRCS 1/8 cutout of MOIRCS Field Image Courtesy Kajisawa

  16. Two z-dropout Candidates? From the First-Year (2006) Data • We see two candidates in our field. However, these sources are identified at 3-5 sigma levels. Are they real?? → Spectroscopic follow-up is going on with MOS spec. mode of MOIRCS this spring. • Except for these 2 sources, we have no candidates down to J=26 → constraining LF at z~8. model MLT stars Ouchi et al. ASPC Ser. in press

  17. Constraints on UV luminosity function at z~8 Luminosity function (LF) of z~8 dropouts • Our z-dropout-search results give upper limits of LF. • Even if two candidates are real, bright-end LF evolves. → Not only for faint galaxies (Bouwens & Illingworth 2006), but also for bright galaxies, number density (luminosity) of dropout galaxies decreases from z=6 to 8 →hierarchical evol.(if UV∝mass) • Adding 2007-2008 data, we will obtain robust candidates and/or a stronger constraint on LF. upper limits (with 0 or2 candidates) Our search goals

  18. Model spectrum of z~8 dropouts Our z=8.8 LAE Search optical bands MOIRCS NB119 • z=8.8 LAEs (NB119 filter ） • z=8.8 LAE search with our narrow-band filter (NB119) centered at 1.19 um (Tokoku/Ouchi et al.) in GOODS. • Observations are being proposed to Subaru. • Unique survey parameters (Depth and volume) • Strong constriant on LF of z~9 LAEs. (never achieved. thanks to MOIRCS’s performance) • Expected number of z=8.8 LAEs • f~4e-18 erg/s/cm^2 → we expect~3.3 LAEs (if no evolution of LF from z~7) z’ J Survey limits of z~9 LAE ←grav. lens search Large Vol. Deep

  19. Higher redshifts with MOIRCS/GOODS search N(expect） • LAEs at redshift higher than z=8.8. • Simulations with realistic OH sky and MOIRCS optics (varying central wavelength+band width). • A highest redshift LAE reached by MOIRCS 30 hour exp. 　　→narrow-band filter for z=10.05 LAE • z=10.05 LAEs (NB134 band） • NB134 band (center 1344nm, band width19.3nm) will be produced this year. (funded by Carnegie observatories). Aiming to detect of ~1 z=10 LAE (or constrain the LF at z=10). NB134 NB119 Results of Simulations

  20. Summary • Introduction • Recent results of our wide-field z=3-7 LyαEmitter studies • We see no evolution of Luminosity function at z=3-5.7, but decrease from z=5.7-7.0.→ evolution neutral fraction of IGM and/or galaxy evolution at z>6 • On-going wide-field NIR search for z=7-9 objects in GOODS • Our MOIRCS dropout/LAE search (2006-2008). • Constraints on z~8 UV luminosity function (decrease a number and/or luminosity of bright-faint galaxies)→ hierarchical evolution? • Summary

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