Masahiro Takada (IPMU) on behalf of the HSC team @GRB conference, - PowerPoint PPT Presentation

Masahiro Takada (IPMU) on behalf of the HSC team @GRB conference, Kyoto, April 20

• What is the Hyper Suprime-Cam (HSC)? • HSC surveys • The major scientific goals • Synergy with other surveys • Summary

Subaru Telescope @ summit of Mt. Mauna Kea (4200m), Big Island, Hawaii

Prime Focus IRCS (AO188) Suprime-Cam Infrared imager and Optical imager (34 ′× 27 ′ ) spectrograph ( λ / Δλ =20,000) HiCIAO (AO188) Coronagraphic imager with Nasmyth differential imaging HDS Focus techniques Optical spectrograph ( λ / Δλ =100,000) AO188 Nasmyth 188-element Focus curvature FOCAS sensing Optical imager and adaptive optics spectrograph system with a Cassegrain COMICS laser guide star Focus IR imager and spectrograph capability MOIRCS NIR imager (7 ′× 4 ′ ) and multi- 4 object (50) spectrograph Illustration by Takaetsu Endo, taken from Nikkei Science 1996

 Only Subaru has the prime focus camera, Suprime- Cam, among other 8-10m class telescope: the wide field-of-view (0.25 sq deg)  Excellent image quality allows accurate shape measurements of galaxies

 Upgrade the prime focus camera  Funded, started since 2006  International collaboration: Japan (NAOJ, IPMU, Tokyo, Tohoku, Nagoya), Princeton, Taiwan  Field-of-View: ~10 × Suprime-Cam  Keep the excellent image quality  Instrumentation well underway (S. Miyazaki, NAOJ)  HSC survey starting from 2012- (~5 years)

Developed by Hamamatsu Photonics-NAOJ collaboration Quantum efficiency HSC previous S-Cam CCDs Improved CCDs in red

 Field of view: 1.5 degrees in diameter  Image quality kept same to that of the current camera, Suprime-Cam, in r, i, z, y bands  The CCD chips with improved quantum efficiency in red bands

Surveys designed fully utilizing its unique capability (wide FoV and depth)  Wide-field survey (>1000 sq. deg.; grizy) Depth: t_exp~15min, i~26 mag (5 σ ) - Probes a comoving volume of ~10Gpc^3 up to z~1.5 - Sciences: later -  Deep survey (~20 sq. deg.; grizy+NIBs) Depth: t_exp~1 hour, i~27 mag - Key sciences: z~6-7 Ly-alpha emitters (survey area > - reionization bubbles), z~6 QSOs, SNe, galaxy evolution studies over z~1-2, GRB orphan afterglow, …  Ultra-Deep survey (a few sq. deg.; grizy+NIBs) Depth: t_exp~20-30 hours, i~28 mag - Key sciences: z~7 Ly-alpha emitters (for understanding - reionization history), SNe Best targets for spectroscopic follow-ups by TMT -

• Ouchi et al. (09): found 22 z~7 z-dropout candidates (one LEA confirmed spectroscopically) over 0.4 sq. deg. area (~(100Mpc)^3)

in ~5 years Current

Exploring the large-scale structure of the Universe Hyper-SC A massive galaxy cluster (>10^3 galaxies) UDF (the previous image) Subaru ~10Mpc or ~30Mlight year@z~0.5  ~0.5deg Other 8m telescopes The Millennium Simulation (Springel et al., Nature 05)

 Gravitational lensing of the hierarchical structures Cosmological lensing: cosmological parameters (DE, neutrino mass) - Cluster lensing (dark matter, cluster physics) - Galaxy group; not yet fully explored so far - Galaxy-scale lensing (weak and strong lensing) -  Finding galaxy clusters out to z~1.5 (y-band) The expected number of massive clusters with 10^15Msun at z>1 - over a 1000 sq. deg. area is only O(1) for LCDM model  QSOs at z~7 (SMBHs; GP test) 10-100 QSOs can be expected if extrapolating the results at z<6.5 -  Galaxy evolution out to z~1  Dwarf satelites in our Milky Way out to ~100kpc in distance (compared to ~10kpc for SDSS) A few satellites expected to be found, for LCDM model - Constraining the mass of DM (the current constraint M WDM <a few keV) -

Lensing strength = (the geometry of the Universe) × (lensing matter [including DM])

d LS ( z L , z S ) d L ( z L ) z S ∫ dz L δ ( z L , θ ) γ ∝Ω m 0 d S ( z S ) 0 for a source galaxy at z s • Lensing efficiency function: W gl – Overall amplitude is sensitive to Ω m , i.e. Ω de if a flat universe is a prior assumed – Sensitive to Hubble expansion through d A , i.e. DE – Depends on source redshift – uncertainty in weak lensing measurements if redshift info is not available • Mass clustering part: δ – Allows to reconstruct the dark matter distribution without resting on any assumptions of the dynamical states – Sensitive to primordial power spectrum (amplitude and shape) – Redshift history of the growth rate is sensitive to DE (structure formation arises from the balance between gravitational instability and cosmic expansion

Strong Lensing - Multiple Images - Large Arcs, Ring - Obvious Distortion Weak Lensing - Slight Stretching - Distortion small compared to initial shape - Statistical lensing to center - The S/N depends on the number of background gals and the accuracy of shape measurement (PSF)

Reyes et al. Nature 2010 Ratio: lensing strength/galaxy cluster strength • In gravity metric theory, lensing is caused by the gravitational potential (g_00) and the curvature perturbation (g_ij) • Galaxy clustering measurement is distorted by the peculiar velocity field, caused by the gravitational potential (g_00) • Reyes et al. used the SDSS clustering stats to explore the consistency relation of GR Distance from the center of lensing galaxies

Subaru S-Cam CFHT (blue: mass) A209 Bardeau, Soucail, Kneib et al.07 Okabe , MT+ 2010, in press Subaru (S-Cam) is currently the best instrument for measuring WL signal, thanks to its image quality and depth

A2390 Bardeau, Soucail, Kneib et al.07 Okabe , MT+ 2010, in press

Merging Clusters: Bullet Cluster (1E 0657-56) HSC-W of 2000 deg.: >10^4 clusters with >10^14Msun WL found clusters are ~ a few x 10^3 O(1) clusters with 10^15 Msun at z>1 ALMA follow-up observations of high-z clusters ~10^2 merging clusters like Bullet Cluster (Hayashi & White 06)

Atacama Cosmology Telescope (148GHz, 218GHz, 277GHz) • Plan to overlap the HSC survey region with that of the SZ experiment ACT (around the ang. res.= 2.34’ equator) • SZ independent of redshift • HSC can determine the redshift of SZ found clusters • Statistical studies of ACT-HSC Abell 3128 (z=0.44) SPT-CL0547 (z=0.88) data for clusters • BOSS redshifts of LRGs (z< 0.7) available • LRGs are landmarks of LSS (most likely bright central galaxies of clusters) • HSC will add faint galaxies surrounding every LRG • Other synergy with Astro-H, ALMA, eROSITA, SDSS-III (BOSS survey) TMT…

• Key factors: other datasets, NIR, spec-z, ACT, ALMA

• Cosmological lensing WL σ 8 ( Ω m /0.25) 0.64 =0.785 ± 0.043 • The current most massive survey is σ 8 CFHT, 170 sq. deg. WMAP • HSC-W: >1000 sq. deg.: dark energy combined and neutrino mass σ 8 =0.771 ± 0.029 Ω m =0.248 ± 0.019 Ichiki, MT, Takahashi 09 Fu+0712.0884 Σ M ν <0.54eV (95% C.L.)

The first question to be addressed: if or not w=-1? (w=-1: cosmological constant) Complementary to the geometrical tests, SNe, BAO, GRBs.. σ (w) DE equation of state ： w σ (w)~0.1 0.1 HSC(+CMB): 0.05 σ (w)~0.02-0.04 LSST, JEDM ρ de ( z ) ∝ (1 + z ) 3(1 + w ) σ (w)~0.01 0.01 2015 2020(?) Today(08) DE density parameter ： Ω _de We may find the evidence of w ≠ -1 earlier MT & Jain (2004) than LSST/JEDM (note: systematics)

From S. Miyazaki

• Hyper Suprime-Cam (HSC) is the next-generation prime focus camera of Subaru: a factor 10 improvement in the survey speed • The fabrication well underway: the survey will start from ~2012 • Many science cases available: wide, deep, ultra-deep surveys – From the local universe to cosmos: dwarf satellites in our Milky Way, distant galaxies, galaxy clusters, QSO, large-scale structure – Weak lensing adds new information on the data: dark matter distribution, which is essential for a quantitative understanding of structure formation • Major scientific goals: dark energy, dark matter, neutrinos, cosmic reionization • Various synergy with future surveys: ACT (SZ effect), ALMA, Astro-H, BOSS, JWST, TMT,….