nir bao search by subaru/fmos

NIR BAO Search byNIR BAO Search bySubaru/FMOSSubaru/FMOS

TomoTomo TotaniTotani

T. Totani (Kyoto Univ)T. Totani (Kyoto Univ) NIR BAO Search by Subaru/FMOSNIR BAO Search by Subaru/FMOS

Subaru/FMOSSubaru/FMOS FFibiberer--MMulti-ulti-OObject bject SSpectrographpectrograph in NIR, in NIR,

400 fibers400 fibers

A Second Generation Common UseA Second Generation Common UseInstrument for the 8.2m Subaru TelescopeInstrument for the 8.2m Subaru Telescope

Collaboration with:Collaboration with: Japan (Kyoto) Japan (Kyoto) UK(OxfordUK(Oxford, Durham, RAL), Durham, RAL) Australia(AAOAustralia(AAO))

First light of objects :2006 spring First light of objects :2006 spring

Open Use S07A? (2007 Feb- Jul) Open Use S07A? (2007 Feb- Jul)

Details will be given by Details will be given by Ohta-sanOhta-san’’ss talk talk


Specification of FMOSSpecification of FMOS 400400　　fibresfibres (1.25 (1.25””ΦΦ) in circular FOV (30) in circular FOV (30’’ ΦΦ))

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

OH Airglow Suppression with OH masks OH Airglow Suppression with OH masks ~1/20 suppression of continuum level ~1/20 suppression of continuum level

75% clearance of the wavelength coverage 75% clearance of the wavelength coverage

Limiting magnitude (1 hr, S/N=5)Limiting magnitude (1 hr, S/N=5) J ~ 22.3J ~ 22.3

H ~ 20.9H ~ 20.9


BAO Search by FMOS. 1BAO Search by FMOS. 1 Target Target RedshiftRedshift: z~1.4-1.7 by detecting : z~1.4-1.7 by detecting HHαα from star from star

forming galaxiesforming galaxies

Required Survey Area to achieve V~ 1GpcRequired Survey Area to achieve V~ 1Gpc33

z~1.4-1.7 z~1.4-1.7 ⇔⇔ ~0.5 ~0.5 comovingcomoving GpcGpc

10 deg 10 deg ⇔⇔ 0.8 0.8 comovingcomoving GpcGpc

300 deg300 deg22 ⇔⇔ ~ 1 Gpc ~ 1 Gpc33 (h=0.7, (h=0.7, ΩΩMM=0.3, =0.3, ΩΩΛΛ=0.7)=0.7)

1500 1500 pointingspointings required for FMOS-FOV (0.2 deg required for FMOS-FOV (0.2 deg22))

1500 x 400 (fibers) = 1500 x 400 (fibers) = 600,000 galaxies600,000 galaxies by 1 pointing per 1 location by 1 pointing per 1 location

Required number of galaxiesRequired number of galaxies 20,000 galaxies per deg20,000 galaxies per deg22 and unit z for the cosmic variance to dominate and unit z for the cosmic variance to dominate

short noise (short noise (GlazebrookGlazebrook & Blake 2005) & Blake 2005)

1,200 galaxies1,200 galaxies for 0.2 deg for 0.2 deg22 (FMOS-FOV) and (FMOS-FOV) and ΔΔzz=0.3=0.3

should be compared the 400 fibersshould be compared the 400 fibers


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

Necessary number of nights: ~O(100)Necessary number of nights: ~O(100) 200 (nights) 200 (nights) ×× 10 ( 10 (pointingspointings/night) = 2,000 /night) = 2,000 pointingspointings

Sensitivity to the Sensitivity to the HHαα Flux: Flux: FMOS S/N=5 (1hr) FMOS S/N=5 (1hr) F(HF(Hαα) ~ 1-2 x 10) ~ 1-2 x 10-17 -17 erg/s/cmerg/s/cm22

galaxy with SFR = 1 galaxy with SFR = 1 MMsunsun/yr @ z=1.5/yr @ z=1.5

L(HL(Hαα) = 1.3 x 10) = 1.3 x 104141 erg/s erg/s

F(HF(Hαα) = 0.86 x 10) = 0.86 x 10-17 -17 erg/s/cmerg/s/cm22


(Too) Many Target Galaxies!(Too) Many Target Galaxies!

Hα Luminosity FunctionHopkins et al. 2000

FMOSsensitivity

400 gals / (0.2 deg2)for z = 1.4-1.7


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 fewplan a special survey of a fewhundreds deghundreds deg22 for FMOS BAO for FMOS BAOsearch?search? From S. Warren


How to select z~1.5 targets?How to select z~1.5 targets?

The K20 Survey, Cimatti et al. ’02.

in FMOS FOV,4000 gals to K=20500 gals to K=17


Required Depth of Input Imaging SurveyRequired Depth of Input Imaging Survey

surface density of K<20surface density of K<20spiral galaxies at z=1.4-1.7 isspiral galaxies at z=1.4-1.7 iscomparable to fiber numbercomparable to fiber numberdensity of FMOSdensity of FMOS photo-z selection?photo-z selection?

K>20 galaxies may alsoK>20 galaxies may alsohave strong have strong HHαα selection primarily by optical?selection primarily by optical?

Prediction by the model of Totani et al. ‘01

400 gals / (0.2 deg400 gals / (0.2 deg22))


Uniqueness & StrengthUniqueness & Strength

Unique Unique redshiftredshift range by range by HHαα in NIR in NIR redshiftredshift desert of 1.5 < z < 2.5 in optical spectroscopy desert of 1.5 < 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 2.5 < z < 3.5 by LyLyαα

The instrument available soon!The instrument available soon! Astronomical first light: 2006 springAstronomical first light: 2006 spring

Open Use S07A? (2007 Feb- Jul) Open Use S07A? (2007 Feb- Jul)

will serve as a pilot project for future WFMOSwill serve as a pilot project for future WFMOS

will remain as a unique data set even in the WFMOS era bywill remain as a unique data set even in the WFMOS era bybeing NIRbeing NIR


Status of the proposalStatus of the proposal working group:working group:

needs to persuade the Japanese community to get >100 nightsneeds to persuade the Japanese community to get >100 nights 20 nights / yr is the maximum for open use20 nights / yr is the maximum for open use

needs to establish the selection procedure from input imagingneeds to establish the selection procedure from input imagingsurveyssurveys

JapanJapan UK/USAUK/USAToshinori Maihara Gavin DaltonKouji Ohta Karl GrazebrookTomonori Totani … Takahiko Matsubara Masahrio Takada…


RoadmapRoadmap a pilot study by using FMOS GTO (20? 40? nights)a pilot study by using FMOS GTO (20? 40? nights)

especially to establish the target selection procedureespecially to establish the target selection procedure

SXDF is a good field for this studySXDF is a good field for this study

optimize the survey parameters for optimize the survey parameters for w/ww/w’’ determination determination

If the prospect is good, start political actionsIf the prospect is good, start political actions appeal to the Subaru committee for a special projectappeal to the Subaru committee for a special project

making the survey useful also for other astrophysicalmaking the survey useful also for other astrophysicalpurposespurposes

a fraction of fibers assigned to some a fraction of fibers assigned to some astrophysicallyastrophysically interesting interestingobjects?objects?

dondon’’t forget sending a good cognac to the Subaru directort forget sending a good cognac to the Subaru director


ConclusionConclusion

NIR BAO search by Subaru/FMOS may give a usefulNIR BAO search by Subaru/FMOS may give a usefuland unique constraint on the dark energy, and will beand unique constraint on the dark energy, and will bean important step to the future WFMOS projectan important step to the future WFMOS project

feasibility study will start soon by FMOS guaranteedfeasibility study will start soon by FMOS guaranteedtimetime


memomemo

sensitivity to sensitivity to HHαα KarlKarl’’s s pptppt: : L(HL(Hαα)=1-2 x 10)=1-2 x 10-17 -17 erg cmerg cm-2-2 s s-1-1

H band limit: 20.9 H band limit: 20.9 2.1 x 10 2.1 x 10-15-15 erg erg cmcm-2-2 s s-1-1

line width ~ resolution R=500 line width ~ resolution R=500 30A 30A

band width ~ 4000Aband width ~ 4000A

2.1 x 102.1 x 10-15-15 x 30/4000 = 1.6 x 10 x 30/4000 = 1.6 x 10-17-17 erg erg cmcm-2-2 s s-1-1

SFR(MsunSFR(Msun/yr) = 7.9 x 10/yr) = 7.9 x 10-42-42 L(HL(Hαα)(erg/s)(erg/s))

nir bao search by subaru/fmos

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