150 likes | 231 Views
≲ ≳. Deep Surveys for High-z Galaxies with Hyper Suprime-Cam. M. Ouchi (OCIW), K. Shimasaku (U. Tokyo), H. Furusawa (NAOJ), & HSC Consortium. Discovery of Large-Scale Struc.& Proto-clusters (Shimasaku+03,Ouchi+05). Discovery of the most distant galaxy at z=7 (Iye+06).
E N D
≲ ≳ Deep Surveys for High-z Galaxieswith Hyper Suprime-Cam M. Ouchi (OCIW), K. Shimasaku (U. Tokyo), H. Furusawa (NAOJ), & HSC Consortium
Discovery of Large-Scale Struc.& Proto-clusters (Shimasaku+03,Ouchi+05) Discovery of the most distant galaxy at z=7 (Iye+06) Suprime-Cam Image (1 pointing: 918 arcmin2) Signature of Cosmic Reionization (kashikawa+06,Shimasaku+06) Detection of 1&2 halo terms (Ouchi+05, Kashikawa+06,Hamana+06) HST/ACS(1pointing) Decrease of UV luminosity function (Ouchi+04,Yoshida+06,cf Iwata+03/7) Identification of substructure around High-z clusters (Kodama+01, Nakata+05,Tanaka+06/07) 141h-1 Mpc First Census of Lya Blobs (Matsuda+04,Saito+06) UV bright population for deep Spec. (Ando+04/06/07,Nagao+04/05) HST/ACS has (had) a superb spatial resolution +sensitivity, but the survey speed, S, for high-z galaxies isS(Suprime) 10 x S(HST)
HSC Surveys for High-z Galaxies HSC Deep & Wide Survey (DWS) ~800 comoving Mpc at z~6-7 HSC Ultra Deep Survey (UDS) Suprime-Cam (1 FoV) UDS: Hubble Ultra-Deep Field Science (i~28mag; for 0”.5 sources) in a 2 deg2 and DWS: Subau/XMM Deep Field Science (i~27) in a 10-20 deg2 Constraining reionization from large statistics (sample size and survey volume) Moreover, great statistics of z~6.6 sources (for galaxy formation cosmological implication??)
HSC: Powerful for High-z Galaxy Studies Expected number of Lya emitters Expected number of dropout galaxies Nexpect(30hr 1 FoV) Nexpect(30hr 1 FoV) HSC • Our calculations show the expected numbers of high-z galaxies, N(HSC) and N(SC) are • z~3-6 : N(HSC)~ 10xN(SC) due to the large FoV • z~7 : N(HSC)~ 30xN(SC) due to the large FoV +high red-sensitivity by Hamamatsu CCDs HSC x10 x10 x30 x30 SC SC M* y
Key Sciences of HSC/UDS and DWS 1. Cosmic reionization 2. Statistics of star-forming galaxies at z=3-7.5 3. Identification of forming galaxy candidates 4. Evolution of dwarf galaxies at z=0-1.5 We do not include science with NIR images, because we have not yet selected target fields with NIR data. At this moment, we consider data with HSC and follow-up spectroscopy.
1. Cosmic Reionization Cosmic reionization predicted by neumerical simulation (Iliev et al. 2006) ? Evolution of neutral fraction of IGM (Fan et al. 2006) z~6: Final stage (GP test;Fan+06) z~11: WMAP3+inst. model(Page+07, Spergel+07) z~6-11: Transition of IGM status Galaxies (blue dots) and ionized bubbles (orange)
Cosmic Reionization Probed with Lya Emitters (LAEs) Lyα line profiles of galaxies at z=8 (Model prediction) Neutral IGM Ionized IGM Intrinsic Lyα Intrinsic LAE dist. absorbed 90 Mpc Obsrvd LAE dist. McQuinn et al. (2007) Dijkstra et al. (2007) • Neutral hydrogen of IGM is constrained by luminosity evolution and clustering properties of Lya emitters (LAEs)
Neutral Fraction of IGM with Luminosity Function and Correlation Function of Lya Emitters (LAEs) LF at z=6.6 from Suprime-Cam data CF at z=6.6 from Suprime-Cam data • LF: L*(z=6.5) ~ 0.6 L*(z=5.7) -> xHI≲0.45 (Kashikawa+06) • CF: b~3-4 (preliminary) -> xHI≲0.3 (Ouchi et al. in prep.) Weak constraints by large statistical uncertainties and field variance. With HSC, we will obtain robust measurements of LF and CF of Lya emitters complementing deep 21cm observations for HI gas with MWA, LOFAR, and SKA. ? ? ? (Large errors)
2. Statistics of star-forming galaxies at z=3-7.5 UV Bright Galaxies at z~7 UV Luminosity Function at z~7 SFR(Mo/yr)= 30 10 1 • Only a handful of z~7 dropout galaxies are identified photomerically (e.g. Bouwens & Illingworth 2006). • No UV bright z~7 galaxies with SFRno dust >20 Mo/yr whose volume density is as small as 10-6Mpc3 • Even in the era of JWST/ELT, such a rare population cannot be found, due to the limitation of survey area. • HSC/UDS+DWS will image an area of 2-20 deg2 down to y~26mag (2-10 x UltraVISTA survey). • Determination of the bright-end LF • Identification of rare bright galaxies at z~7 that will be ideal targets for spectroscopy with JWST/ELTs. HST JWST/ELT HSC/UDS HSC/DWS
Statistics of z≲6 galaxies • Precision measurements of LF and CF • Constraining star-forming galaxies with numerical simulation, halo occupation distribution (HODs) and conditional luminosity func. models z=4 LBG correlation function fit by HOD model (Ouchi+06,Hamana+06) z=4 Mass-luminosity relation by conditional luminosity func. model (Cooray+06)
3. Forming Galaxies (Cooling cloud/PopIII) Lyα • In the first stage of galaxy formation • Primodial gas become cool and infall into the center of dark halo with cooling radiation (cooling cloud)→ spatially-extended strong Lya emission and weak HeIIλ1640. • Massive star-formation from primodial gas with flat IMF (popIII)→ strong Lya and weak HeIIλ1640 • The first stage of galaxy formation is characterized by strong Lya and weak HeII • We should search for strong Lya emitters (with a large EW), and find forming galaxies • Any candidates of forming galaxies at z~3-7.5? Theoretical models predict • A bright cooling cloud with HeIIλ1640 can be found in a volume of ~105 Mpc3 at z~2-3(Yang et al. 2006) . • At z=5, ~1/1000 of cosmic SFR is constibuted by popIII (Trac & Cen 2006) HeII λ1640 cooling clouds predicted by numerical simulations (Yang et al. 2006)
Candidates of forming galaxies?? Lya blobs at z=3 (size~30-200 kpc) EW distribution of Lya emitters Cannot be explained by ordinary SF (Salpeter IMF) (Matsuda et al. 2004) Ouchi et al. (2007) • Large Lya EW objects including Lya blobs and compact Lya emitters (e.g. Matsuda+04, Saito+06, Nilsson+06) • We see no HeII emission line originated from cooling clouds or popIII (e.g. Dawson+04,Nagao+06,Ouchi+07, c.f. Jemenez+06)
Cooling Cloud+PopIII Search with HSC Saito et al. 2006 • Wide-field+high sensitivity are key • Small number density (cooling cloud~10-5 Mpc, popIII is less than that?) • HSC data are appropriate • Supply the targets to JWST and TMT for identifying HeII by spectroscopy • Distinguish with HeII from AGN using CIV1549(+X-ray data) • Distinguish with HeII from WR-stars using the line width (<1000km/s) Volume limit of SPCAM search
4. Evolution of dwarf galaxies at z=0-1.5 Luminosity function of z=1 galaxies in the HUDF • Statistics of high-z dwarf galaxies (halo mass from clustering, stellar mass etc.) and characterize building blocks. (spectroscopic follow-up with JWST+TMT)
Summary • Survey Designs of HSC/UDS and DWS • Key Sciences of HSC Deep Surveys 1. Cosmic reionization 2. Statistics of star-forming galaxies at z=3-7.5 3. Wide-field search for forming galaxies 4. Evolution of dwarf galaxies at z=0-1.5 (See the HSC white paper for more details) Your ideas, discussions, and participation are needed!!