FastSoundFastSound A BAO Survey in NIR using Subaru/FMOSA BAO Survey in NIR using Subaru/FMOS

戸谷 友則戸谷 友則TOTANI, TomonoriTOTANI, Tomonori

(Kyoto University, Dept. Astronomy)(Kyoto University, Dept. Astronomy)

Spectroscopy in Cosmology and Galaxy Evolution 2005-2015Spectroscopy in Cosmology and Galaxy Evolution 2005-2015Granada, Spain 2007, Oct 3-5Granada, Spain 2007, Oct 3-5

Specification of FMOSSpecification of FMOS 400 fibres in circular FOV (30’ Φ) 400 fibres in circular FOV (30’ Φ)

Each fiber (1.25”) covers 1’ radius FOVEach fiber (1.25”) covers 1’ radius FOV

wavelength coverage: 0.9um - 1.8umwavelength coverage: 0.9um - 1.8um fully covered in a low resolution modefully covered in a low resolution mode

Spectral resolutionSpectral resolution Low resolution mode: R=500Low resolution mode: R=500 High resolution mode: R=2200High resolution mode: R=2200

Limiting magnitude (1 hr, S/N=5)Limiting magnitude (1 hr, S/N=5) J ~ 22.0J ~ 22.0 H ~ 20.0H ~ 20.0 Line ~ 6 x 10Line ~ 6 x 10-17 -17 erg/s/cmerg/s/cm2 2 (Latest number from M. Tamura)(Latest number from M. Tamura) OH airglow suppression systemOH airglow suppression system

Engineering first light: 2008 JanEngineering first light: 2008 Jan

Quick Look of FastSoundQuick Look of FastSound BAO search by Subaru/FMOS with NIR spectroscopy BAO search by Subaru/FMOS with NIR spectroscopy

Hα emitting galaxiesHα emitting galaxies 、、 z~0.5-1.7z~0.5-1.7 planned parameters (final):planned parameters (final):

~600,000 galaxies~600,000 galaxies ~300 deg~300 deg22 O(100) Subaru nightsO(100) Subaru nights

The name stands for ...The name stands for ... FAST: FMOS FAST: FMOS 暗黒振動探査 暗黒振動探査 (FMOS Ankoku Shindou Tansa = FMOS d(FMOS Ankoku Shindou Tansa = FMOS d

ark oscillation survey)ark oscillation survey) SOUND: Subaru Observation Understanding Nature of Dark EnergySOUND: Subaru Observation Understanding Nature of Dark Energy

Status:Status: Survey design and plan now under studySurvey design and plan now under study Recognized as important the potential largest program in the FMOS teaRecognized as important the potential largest program in the FMOS tea

mm final survey design by using real FMOS data (next year)final survey design by using real FMOS data (next year) Proposal to be submitted to Subaru after thatProposal to be submitted to Subaru after that

Unique/Good Points of FastSoundUnique/Good Points of FastSound BAO survey in NIR with a 8m telescopeBAO survey in NIR with a 8m telescope

Unique redshift range by Hα in NIR (z~0.5-1.7)Unique redshift range by Hα in NIR (z~0.5-1.7) redshift desert of 1.3 < z < 2.5 in optical spectroscopy redshift desert of 1.3 < z < 2.5 in optical spectroscopy

0.5 < z < 1.3 by [O II]0.5 < z < 1.3 by [O II] 2.5 < z < 3.5 by Lyα2.5 < z < 3.5 by Lyα

Targeting the first detection of BAO at z>1 by galaxy surveysTargeting the first detection of BAO at z>1 by galaxy surveys would remain as important BAO data even in WFMOS erawould remain as important BAO data even in WFMOS era

Hα is a better tracer of SFR than [OII] or LyαHα is a better tracer of SFR than [OII] or Lyα Photometric target selection likely easierPhotometric target selection likely easier

Instrument available soon!Instrument available soon!

BAO Search by FMOS. 1BAO Search by FMOS. 1 Required Survey Area to achieve V~ 1GpcRequired Survey Area to achieve V~ 1Gpc33

300 deg300 deg22 ⇔ ~ 1 Gpc ⇔ ~ 1 Gpc33 for z~1-1.5 for z~1-1.5 1500 pointings required for FMOS-FOV (0.2 deg1500 pointings required for FMOS-FOV (0.2 deg22))

Required number of galaxiesRequired number of galaxies ~20,000 galaxies per deg~20,000 galaxies per deg22 and unit z for the cosmic variance to and unit z for the cosmic variance to

dominate shot noise (nP >~ 1)dominate shot noise (nP >~ 1) ~1,800,000 galaxies in 300 deg~1,800,000 galaxies in 300 deg22 1,200 galaxies1,200 galaxies for 0.2 deg for 0.2 deg22 (FMOS-FOV) and Δz=0.3 (FMOS-FOV) and Δz=0.3

should be compared the 400 fibers of FMOSshould be compared the 400 fibers of FMOS

BAO Search by FMOS. 2BAO Search by FMOS. 2

Necessary number of nights: ~O(100)Necessary number of nights: ~O(100) 1500 (FOVs) / 10 (FOVs/night) = 150 nights1500 (FOVs) / 10 (FOVs/night) = 150 nights

Sensitivity to the Hα Flux:Sensitivity to the Hα Flux: FMOS S/N=5 (1hr) FMOS S/N=5 (1hr) F(Hα) ~ 6 x 10 F(Hα) ~ 6 x 10-17 -17 erg/s/cmerg/s/cm22

L(Hα) = 9.1 x 10L(Hα) = 9.1 x 104141 erg/s erg/s galaxy with SFR = 6.9 Mgalaxy with SFR = 6.9 Msunsun/yr @ z=1.5/yr @ z=1.5

Effective Volume:Effective Volume: Comparison with Other SurveysComparison with Other Surveys

σP/P~(4πk2dk Veff)-1/2

~20 nights

~200 nights

Eisenstein+ ‘05

BAO peaks

FMOS Survey Simulation (1)FMOS Survey Simulation (1)

300 deg2, 600,000 galaxies (400 galaxies per FMOS FOV)b=2

Key QuestionsKey Questions

Do we have enough number density of galaxies with sufficiently stroDo we have enough number density of galaxies with sufficiently strong Hα flux?ng Hα flux?

Can we select them efficiently by photometric information?Can we select them efficiently by photometric information?

Do we have sufficient photometric data, or can we obtain them in thDo we have sufficient photometric data, or can we obtain them in th

e near future?e near future?

Some Tests for Target SelectionsSome Tests for Target Selections

Estimate Hα flux from photEstimate Hα flux from photo-z by using SDF/SXDF do-z by using SDF/SXDF data (~1degata (~1deg22)) BVRizJK+SpitzerBVRizJK+Spitzer

There are sufficent numbeThere are sufficent number of Hα bright galaxies at zr of Hα bright galaxies at z<1.4<1.4

z>1.5 galaxies may not be z>1.5 galaxies may not be sufficient enough sufficient enough

FMOS line sensitivity (1hr, SN=5)

A Candidate Imaging Catalog for Target Selection:A Candidate Imaging Catalog for Target Selection:CFHT-Wide Synoptic SurveyCFHT-Wide Synoptic Survey

-almost correct area-deep enough for Fast Sound-five band photometries for target selection

Scientific GoalsScientific Goals Stage 1:Stage 1:

~50 nights (not very difficult to get as a Subaru large program)~50 nights (not very difficult to get as a Subaru large program) may not clearly detect BAO, but may see some evidencemay not clearly detect BAO, but may see some evidence precise measurement of P(k) at z~1precise measurement of P(k) at z~1

P(k) measurement is important for cosmological parameters, even without BP(k) measurement is important for cosmological parameters, even without BAOAO

Use P(k) shape to derive cosmological constraints (c.f. WMAP+2dF, WMAPUse P(k) shape to derive cosmological constraints (c.f. WMAP+2dF, WMAP+SDSS, …)+SDSS, …)

z~1 is important for dark energyz~1 is important for dark energy

Stage 2:Stage 2: ~a few hundreds nights~a few hundreds nights clear detection of BAOclear detection of BAO more robust constraint on dark energy than Stage 1more robust constraint on dark energy than Stage 1

Ancillary sciences:Ancillary sciences: Properties of z~1 star formation galaxiesProperties of z~1 star formation galaxies A small fraction of fibers for spectroscopic survey of rare objectsA small fraction of fibers for spectroscopic survey of rare objects

The Most Crucial QuestionThe Most Crucial Question

Can we get such a large observing time of Subaru?Can we get such a large observing time of Subaru?

The Future of Subaru Large ProgramsThe Future of Subaru Large Programs So far: So far:

Maximum 20 nights for open useMaximum 20 nights for open use

A new opportunity: A new opportunity: The Subaru Strategic Observation ProgramsThe Subaru Strategic Observation Programs Two categoriesTwo categories

A historical survey programA historical survey program A systematic project with a clear scientific objective A systematic project with a clear scientific objective

<~60 nights / yr, up to ~5 yrs <~60 nights / yr, up to ~5 yrs maximally 300 nights maximally 300 nights Responding to the commission of a new instrumentResponding to the commission of a new instrument the first call for proposal (for HiCiao+AO) now under review procthe first call for proposal (for HiCiao+AO) now under review proc

essess ““Subaru Strategic Exploration of Exoplanets and Disks with HICIAO/Subaru Strategic Exploration of Exoplanets and Disks with HICIAO/

AO188”, PI: M. TamuraAO188”, PI: M. Tamura Next call will be for FMOS!Next call will be for FMOS!

The RoadmapThe Roadmap Stage 0: pilot survey using a fraction of FMOS GTO (2008)Stage 0: pilot survey using a fraction of FMOS GTO (2008)

test of target selection criteriatest of target selection criteria optimization of the survey parametersoptimization of the survey parameters formal proposal to Subaru for a large program formal proposal to Subaru for a large program

Stage 1: using ~50 nights, ~60 degStage 1: using ~50 nights, ~60 deg22 (2009-?) (2009-?) precise measurement of P(k) at z~1precise measurement of P(k) at z~1 hopefully evidence for BAOhopefully evidence for BAO

Stage 2: complete survey of 170 degStage 2: complete survey of 170 deg22 CFTHLS-W field CFTHLS-W field a good chance for detecting BAOa good chance for detecting BAO

Stage 3: ultimate >300 degStage 3: ultimate >300 deg22 survey survey clear detection of BAOclear detection of BAO but needs another source of imaging catalog for target selectionbut needs another source of imaging catalog for target selection

certainlycertainly

likelylikely

possiblypossibly

Who knows!?Who knows!?

Hα Flux, Stellar Mass, SizeHα Flux, Stellar Mass, Size BizBiz

0.2”/pix

Input Imaging SurveysInput Imaging Surveys UKIDSS Large Area SurveyUKIDSS Large Area Survey

4000 deg4000 deg22 K < 18.4K < 18.4

VISTA & VSTVISTA & VST DeepDeep

100 deg100 deg22 K<21.0K<21.0

WideWide 3000 deg3000 deg22

K<19.5K<19.5 plan a special survey of a few plan a special survey of a few

hundreds deghundreds deg22 for FMOS BAO search? for FMOS BAO search?

ＮＩＲサーベイは必ずしも必要ないか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？もしれない。可視サーベイ？ From S. Warren