1 / 20

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 :

kalb
Télécharger la présentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related