1 / 19

FastSound A BAO Survey in NIR using Subaru/FMOS

FastSound A BAO Survey in NIR using Subaru/FMOS. 戸谷 友則 TOTANI, Tomonori (Kyoto University, Dept. Astronomy) Spectroscopy in Cosmology and Galaxy Evolution 2005-2015 Granada, Spain 2007, Oct 3-5. Specification of FMOS. 400 fibres in circular FOV (30’ Φ)

byrona
Download Presentation

FastSound A BAO Survey in NIR using Subaru/FMOS

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. FastSoundA BAO Survey in NIR using Subaru/FMOS 戸谷 友則 TOTANI, Tomonori (Kyoto University, Dept. Astronomy) Spectroscopy in Cosmology and Galaxy Evolution 2005-2015 Granada, Spain 2007, Oct 3-5

  2. Specification of FMOS • 400 fibres in circular FOV (30’ Φ) • Each fiber (1.25”) covers 1’ radius FOV • wavelength coverage: 0.9um - 1.8um • fully covered in a low resolution mode • Spectral resolution • Low resolution mode: R=500 • High resolution mode: R=2200 • Limiting magnitude (1 hr, S/N=5) • J ~ 22.0 • H ~ 20.0 • Line ~ 6 x 10-17 erg/s/cm2 (Latest number from M. Tamura) • OH airglow suppression system • Engineering first light: 2008 Jan

  3. Quick Look of FastSound • BAO search by Subaru/FMOS with NIR spectroscopy • Hα emitting galaxies、z~0.5-1.7 • planned parameters (final): • ~600,000 galaxies • ~300 deg2 • O(100) Subaru nights • The name stands for ... • FAST: FMOS 暗黒振動探査 (FMOS Ankoku Shindou Tansa = FMOS dark oscillation survey) • SOUND: Subaru Observation Understanding Nature of Dark Energy • Status: • Survey design and plan now under study • Recognized as important the potential largest program in the FMOS team • final survey design by using real FMOS data (next year) • Proposal to be submitted to Subaru after that

  4. Unique/Good Points of FastSound • BAO survey in NIR with a 8m telescope • Unique redshift range by Hα in NIR (z~0.5-1.7) • redshift desert of 1.3 < z < 2.5 in optical spectroscopy • 0.5 < z < 1.3 by [O II] • 2.5 < z < 3.5 by Lyα • Targeting the first detection of BAO at z>1 by galaxy surveys • would remain as important BAO data even in WFMOS era • Hα is a better tracer of SFR than [OII] or Lyα • Photometric target selection likely easier • Instrument available soon!

  5. BAO Search by FMOS. 1 • Required Survey Area to achieve V~ 1Gpc3 • 300 deg2 ⇔ ~ 1 Gpc3 for z~1-1.5 • 1500 pointings required for FMOS-FOV (0.2 deg2) • Required number of galaxies • ~20,000 galaxies per deg2 and unit z for the cosmic variance to dominate shot noise (nP >~ 1) • ~1,800,000 galaxies in 300 deg2 • 1,200 galaxies for 0.2 deg2 (FMOS-FOV) and Δz=0.3 • should be compared the 400 fibers of FMOS

  6. BAO Search by FMOS. 2 • Necessary number of nights: ~O(100) • 1500 (FOVs) / 10 (FOVs/night) = 150 nights • Sensitivity to the Hα Flux: • FMOS S/N=5 (1hr)  F(Hα) ~ 6 x 10-17 erg/s/cm2 • L(Hα) = 9.1 x 1041 erg/s • galaxy with SFR = 6.9 Msun/yr @ z=1.5

  7. Effective Volume:Comparison with Other Surveys BAO peaks ~200 nights ~20 nights Eisenstein+ ‘05 σP/P~(4πk2dk Veff)-1/2

  8. FMOS Survey Simulation (1) 300 deg2, 600,000 galaxies (400 galaxies per FMOS FOV) b=2

  9. Key Questions • Do we have enough number density of galaxies with sufficiently strong Hα flux? • Can we select them efficiently by photometric information? • Do we have sufficient photometric data, or can we obtain them in the near future?

  10. Some Tests for Target Selections • Estimate Hα flux from photo-z by using SDF/SXDF data (~1deg2) • BVRizJK+Spitzer • There are sufficent number of Hα bright galaxies at z<1.4 • z>1.5 galaxies may not be sufficient enough FMOS line sensitivity (1hr, SN=5)

  11. A Candidate Imaging Catalog for Target Selection:CFHT-Wide Synoptic Survey -almost correct area -deep enough for Fast Sound -five band photometries for target selection

  12. Scientific Goals • Stage 1: • ~50 nights (not very difficult to get as a Subaru large program) • may not clearly detect BAO, but may see some evidence • precise measurement of P(k) at z~1 • P(k) measurement is important for cosmological parameters, even without BAO • Use P(k) shape to derive cosmological constraints (c.f. WMAP+2dF, WMAP+SDSS, …) • z~1 is important for dark energy • Stage 2: • ~a few hundreds nights • clear detection of BAO • more robust constraint on dark energy than Stage 1 • Ancillary sciences: • Properties of z~1 star formation galaxies • A small fraction of fibers for spectroscopic survey of rare objects

  13. The Most Crucial Question • Can we get such a large observing time of Subaru?

  14. The Future of Subaru Large Programs • So far: • Maximum 20 nights for open use • A new opportunity: The Subaru Strategic Observation Programs • Two categories • A historical survey program • A systematic project with a clear scientific objective • <~60 nights / yr, up to ~5 yrs  maximally 300 nights • Responding to the commission of a new instrument • the first call for proposal (for HiCiao+AO) now under review process • “Subaru Strategic Exploration of Exoplanets and Disks with HICIAO/AO188”, PI: M. Tamura • Next call will be for FMOS!

  15. The Roadmap certainly • Stage 0: pilot survey using a fraction of FMOS GTO (2008) • test of target selection criteria • optimization of the survey parameters • formal proposal to Subaru for a large program • Stage 1: using ~50 nights, ~60 deg2 (2009-?) • precise measurement of P(k) at z~1 • hopefully evidence for BAO • Stage 2: complete survey of 170 deg2 CFTHLS-W field • a good chance for detecting BAO • Stage 3: ultimate >300 deg2 survey • clear detection of BAO • but needs another source of imaging catalog for target selection likely possibly Who knows!?

  16. Hα Flux, Stellar Mass, Size • Biz 0.2”/pix

  17. Input Imaging Surveys • UKIDSS Large Area Survey • 4000 deg2 • K < 18.4 • VISTA & VST • Deep • 100 deg2 • K<21.0 • Wide • 3000 deg2 • K<19.5 • plan a special survey of a few hundreds deg2 for FMOS BAO search? • NIRサーベイは必ずしも必要ないかもしれない。可視サーベイ? From S. Warren

More Related