- By
**amena** - Follow User

- 123 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about ' Emission Lines for BAO: Ground & Space' - amena

**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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### Emission Lines for BAO: Ground & Space

M. Lampton

UCB SSL

1 Dec 2006

Rewrites May 2007, Sept 2009, Nov 2009

Intro

- Much previous BAO work has used LRGs: very bright! But few in number
- Emission line galaxies are more numerous but not so bright
- Star Formation Rate is gauged by emission lines esp Hα and [O II]
- [O II] 3727 can accomplish a lot from mountaintops: 1 micron is z=1.68
- Hα 6563 although stronger, requires spaceborne observatory
- Then there’s [O III] 5007, yet another tool.

M.Lampton Sept 2009

Plan

1. BAO Goals: nP ~ 1 and lots of modes

2. Review SFR(z) and model it

3. Review LF(z) for Halpha and [O II]

4. Model LF(z) for Halpha and [O II]

5. Predict harvests of BAO surveys, space and ground.

Rough analogy to Parkinson et al “Optimizing BAO Surveys” arXiv 0702040 which was done to optimize WFMOS (ground only): they found it best to concentrate on 0.8<z<1.4 over the widest possible sky area and to kiss off Lyα at z~3.

Throughout: I adopt a “737” cosmology.

M.Lampton Sept 2009

Step 1: Uncertainties in the Acoustic Scale Lengthe.g. Blake et al 0510239 (2005); see also Reid et al 0907.1659

P(k) from Cole et al 2dFGRS arXiv 0501174, Fig.15

Cosmic variance

Shot noise

M.Lampton Sept 2009

Step 2: SFR, Hα, [O II] are strongly correlated

Local, SDSS: Sumiyoshi et al arXiv:0902.2064 (2009) Fig 3

Local; Kennicutt, Ap.J. 388, 310 (1992)

Sum of 3727, 3729

Hα 6563 singlet

M.Lampton Sept 2009

Step 2: ELGs are widely used for SFR estimationLy et al., ApJ 657 738 (2007)

M.Lampton Sept 2009

Step 2: Review and model SFR(z)

The Compilation:

Hopkins & Beacom ApJ 651, 142 (2006) Fig.1

The parabola:

log(SFR)=-2.00+5*(x – x2) where x=log(z+1)

See also Gonzales et al arXiv 0909.3517

M.Lampton Sept 2009

Step 3: LF data, Hα, continuedfaint end: Subaru; Ly et al., Subaru, ApJ 657 738 (2007), Fig 10

z=0.08

z=0.24

z=0.40

M.Lampton Sept 2009

HiZELS: a high redshift survey of Hα emitters.

I: the cosmic star-formation rate and clustering at z = 2.23

J. E. Geach et al; UKIRT HiZELS: NIR narrowband at 2.12um, COSMOS field 0.6 sqdeg

arXiv:0805.2861v1

M.Lampton Sept 2009

MULTI-WAVELENGTH CONSTRAINTS ON THE COSMIC STAR FORMATION HISTORY FROM SPECTROSCOPY: THE REST-FRAME UV, H, AND INFRARED LUMINOSITY FUNCTIONS AT REDSHIFTS 1.9<z < 3.41

Reddy et al arXiv:0706.4091: 2000 SpectroZ, 15000 PhotoZ; Steidel Keck I w/ LRIS (2004)

M.Lampton Sept 2009

Step 3: LF data [O II]Ly et al., Subaru w/ narrowband filters; ApJ 657 738 (2007) Fig 12

z=0.89

z=0.91

z=1.19

z=1.47

M.Lampton Sept 2009

Step 3: LF data, [O II], continuedZhu et al., arXiv 0811.3035: DEEP2 (Keck II + DEIMOS), 14000 galaxies

M.Lampton Sept 2009

Step 3, continued: how about [O III] 5007?Ly et al., Subaru Deep Field; ApJ 657 738 (2007) Fig. 11

z=0.41

z=0.42

z=0.63

z=0.84

M.Lampton Sept 2009

Step 3 concluding:LF compilationSumiyoshi et al: Compilation based on data from SDF; arXiv 0902.2064

Halpha [O II]

0.5<z<1.0

1.0<z<1.4

1.4<z<1.7

M.Lampton Sept 2009

Step 4: Model the LF(z) for each line

Simplest Abell Luminosity Function

- Abell model (ARAA v.3, 1-22, 1965) parameters Lb, Nb at the break;
- Nearly flat power law at faint end
- Break
- Nearly inverse-square power law at bright end
- Schechter model (ApJ 203, 297-306, 1976) parameters L*, Φ* at the break;
- Nearly flat power law at faint end
- Break
- Exponential decrease at bright end
- Both developed for galaxy continuua
- They differ only at the bright end: Abell=slope; Schechter=dropoff.
- Which might apply for line emission?
- Because of the log-log straight-line LFs seen in DEEP2 (which go to very sparse densities) I adopt the Abell model here.
- Other adopters: Hao et al 0501042 (ELGs); Croom et al MNRAS 349 1397 2004 (QSOs)

M.Lampton Sept 2009

log(Nb) = -3.5+2.0*(x-x²)

log(Lb) = +41.5+3.0*(x-x²)

where x = log10(1+z)

Sumiyoshi et al (2009)

0.5<z<1.0

1.0<z<1.4

1.4<z<1.7

M.Lampton Sept 2009

Step 4: [O II] LF model

log(Nb) = -3.5+2.0*(x-x²)

log(Lb) = +41.1+3.0*(x-x²)

where x = log10(1+z)

0.5<z<1.0

1.0<z<1.4

1.4<z<1.7

M.Lampton Sept 2009

log(Nb) = -3.5+2.0*(x-x²)

log(Lb) = +41.1+3.0*(x-x²)

DEEP2; Zhu et al., arXiv 0811.3035

M.Lampton Sept 2009

Step 5: Survey Yieldassumes “737” universe

M.Lampton Sept 2009

Abell distribution eyeball fitted to Sumiyoshi et al 2009 Hα

NEWS FLASH : Previously sought nP=1 and Zmax=2; but Linder and others (this conference) recommend NP=2 or even 3; Zmax=1.7 not 2.0

For a given nP, what Hα flux do we expect?This extrapolated LF based on Sumiyoshi has many uncertainties, and the JDEM BAO team has recommended a higher sensitivity, ~ 1.6E-16 erg/cm2s

M.Lampton Sept 2009

For a given nP, what [O II] flux do we expect?

Abell distribution eyeball fitted to Sumiyoshi et al 2009 [O II] 3727+3729

BigBOSS White Paper Fig.2 based on DEEP2 and VVDS

Goal: doublet flux ~ 1E-16 erg from this alone. But atmospheric observing complications and uncertainties about the LF at z>1.5 argue for higher sensitivity; working goal = 2.5E-17 erg/cm2sec for each component.

M.Lampton Sept 2009

Atmospheric Transmission at Gemini Northpresumably similar at KPNO?http://www.gemini.edu/sciops/ObsProcess/obsConstraints/ocTransSpectra.html

U B V R I Z Y J H K

5.0mm H2O

M.Lampton Sept 2009

Atmospheric Emissionhttp://www.gemini.edu/node/10781?q=node/10787#OpticalSkySpectrum

M.Lampton Sept 2009

MDLF Results for BigBOSSGoal is to use < 1 hour exposures and get SNR=8 (see chart 22)…at z=2: 2.5E-17 erg/cm2s, will need the whole 4ksecat z=1: 1E-16 erg/cm2s, will need < 1 ksec

At Tobs = 1 h, 4000 fibers and 100 nights/year at 8h/night is 3 million targets per year -- and of course there is additional yield since most targets have z<2.0 and so won’t need the full 4000 seconds of exposure each,so smart fiber reallocation can improve yield rather than SNR.

M.Lampton Sept 2009

MDLF Results for JDEMGoal is to use ~ 1ksec exposures Hα and get SNR>6…at z=2: can get to 2.5E-16 erg/cm2s, using 1ksecat z=1: with 1ksec will gain improved SNR

At 1 kilosec exposures, 6 MCT sensors & 0.5 arcsec pixels, the FOV is 0.46 sq degrees. With 100 sec lost per maneuver and 70% on orbit efficiency, the net survey rate is 9000 square degrees per year.

M.Lampton Sept 2009

Recent Relevant Results!

Conclusions

- JDEM-BAO: entirely feasible!
- BigBOSS: entirely feasible!

- Geach et al “Empirical Halpha emitter count predictions for dark energy surveys” arXiv 0911.0686: ELGs, Ha, 0.5<z<2.
- Parkinson et al “Optimizing BAO surveys II: curvature, redshifts, and external datasets” arXiv 0905.3410
- Hutsi, “Power spectrum of the maxBCG sample: detection of AO using galaxy clusters” arXiv 0910.0492
- Stril et al, “Testing Standard Cosmology with Large Scale Structure” arXiv0910.1833; specifically compares BigBOSS vs JDEM-PS.

M.Lampton Sept 2009

Download Presentation

Connecting to Server..