weighing neutrinos including the largest photometric galaxy survey: megaz dr7

Weighing Neutrinos including the Largest Photometric Galaxy Survey: MegaZ DR7

Moriond 2010Shaun Thomas: UCL

“A combined constraint on the Neutrinos” Arxiv: 0911.5291

Outline:

1. Neutrinos have mass!

2. Neutrino signatures in cosmology

3. Probes of the Model

• Cosmic Microwave Background

• Galaxy Surveys

• Supernovae and Baryon Oscillations

4. Work: Thomas, Abdalla & Lahav (2009): arXiv:0911.5291 (+ In prep. 2010)

5. For the Future…?


Neutrino oscillations indicate they have mass!

But not on the absolute scale of mass…

• Beta-decay kinematics

• Neutrinoless double beta-decay

• Cosmology!

KATRIN

nemo

Thomas, Abdalla, Lahav (2009)

For example…

Not just interesting physics but,an integral part of the cosmological model… Age of precision Cosmology


http://www-ik.fzk.de/~katrin/index.html

Signatures in the Model

• Act as radiation or matter and affect the Universe’s expansion history

• Suppress the growth of matter structure and cosmological perturbations

Neutrinos have large thermal velocities and Free-stream out of over-densities/inhomogeneities thus suppressing the clustering of matter and galaxies

Which we might see in a power spectrum…


Neutrino fraction is directly related to sum of masses (RHS)

Probes of CosmologyCosmic Microwave Background (CMB)

WMAP 5 year (CMB) : < 1.3 eV (95% CL)Komatsu et al. [arXiv:0803.0547]

Thomas et al. [arXiv:0911.5291]

Model Data Constraint

With the CMB the effect depends on whether neutrinos are relativistic or not:


• Suppress potentials - change heights of peaks OR

• Affect matter-radiation balance

Suggestive of a CMB limit ~ 1.5 eV (E.g. Ichikawa 05)

Probes of Cosmology

Supernovae (SN)E.g. Supernova Legacy Survey

CMB + SN + BAO : < 0.69 eV (95% CL)

Baryon Acoustic Oscillations (BAOs)

Standard candle allows one to measure the expansion history

Tighter matter/hubble constraint aids neutrino determination

Standard ruler allows one to measure the expansion history

Tighter matter/hubble constraint aids neutrino determination

Primordial CMB photon-baryon oscillations are imprinted onto late-time matter power spectrum: BAO

Thomas et al. [arXiv:0911.5291]Komatsu et al. [arXiv:0803.0547]


E.g. Percival et al

Probes of Cosmology+ Galaxy Clustering! Sloan Digital Sky Survey (SDSS)

• Suppress the growth of matter structure and cosmological perturbations

Smaller Scales



Thomas, Abdalla & Lahav - in prep

Luminous Red Galaxies (LRGs)

Photometric Redshift

Largest galaxy survey

723,556 LRGs7,746 square degrees

Volume: 3.3 (Gpc /h)^30.45 < z < 0.65

ANNz - Collister and Lahav 2004Padmanabhan et al. 2007

Four redshift bins

Moriond 2010Shaun Thomas: UCL2SLAQ - 13’000 spectroscopic training/evaluation set


Including the production of a new SDSS galaxy clustering angular power spectra

Thomas, Abdalla & Lahav - in prep

We can use this with the BAO(!) - Improves combined neutrino constraint further!

One of the largest galaxy surveys to date


MegaZ DR7


Luminous Red Galaxies (LRGS)4 bins: 0.45 < z < 0.65

CMB + SN + BAO + SDSS LRGs + HST: < 0.28 eV (95% CL)

Thomas et al. [arXiv:0911.5291]

MegaZ DR7


12 Parameters:

€

€

Ωbh2;Ωch

2;ΩΛ;τ ;ns;ln(1010As); mυ ;ASZ ;b1;b2;b3;b4∑

Max multipole l=300

Thomas, Abdalla & Lahav [0911.5291]

Cosmology and Neutrinos

Komatsu et al. [arXiv:0803.0547] < 1.3 eV (CMB) < 0.67 eV (CMB+SN+BAO)

Tereno et al. [arXiv:0810.0555] < 0.54 eV (CMB+SN+BAO+WL)

Ichiki, Takada & Takahashi [arXiv:0810.4921] < 0.54 eV (CMB+SN+BAO+WL)

Seljak et al. [arXiv:0604335] < 0.17 eV (+ Lyman Alpha…)

Systematics - e.g. winds?

Using all the aforementioned probes for complementary data constraint Recent BAO data and production of newest galaxy

clustering angular power spectrumCMB+SDSS+SN+BAO+HST

CMB + SN + BAO + SDSS LRGs +HST

With luminous Red Galaxies (LRGs) sampling a large cosmic volume

Cosmology is starting to predict that experiments such as KATRIN (mentioned earlier) will not detect anything


0.28 eV

WOOHOO!


‘Systematics and Limitations’

Cosmology = Good

However

Parameter DegeneraciesGalaxy Bias Non-linearities

Most quoted results assume cosmological constant cosmology

Degeneracy with w increases error bar

Model underlying matter power spectrum but measure the galaxy power spectrum

Scale dependence…mimic…?

Bias result or lose data

Perturbation theory/ N-body simulations

Although we want tighter neutrino constraints We also want trustworthy neutrino constraints.

Work In Progress…


Work for the Future…

E.g. Saito et al 09Brandbyge & Hannestad 09

E.g. Hannestad

L_max = 300 => 0.28 eV

L_max = 200 => 0.34 eV

Summary

• Cosmology is a sensitive neutrino experiment! (Funded billions of years ago!)

• Massive neutrinos suppress the growth of structure

• Probes such as galaxy clustering or weak lensing are sensitive to growth

• Integral part of cosmological model and parameter space

• Have a complete complementary constraint on neutrinos (sub eV region)

• Systematics and limitations still exist though…

• The Future is promising but with work to be done…Tighter neutrino constraint. Trustworthy neutrino constraint.

Having produced data for a tighter constraint


Related and Further Reading

Cosmology and Neutrinos

Thomas, Abdalla & Lahav [arXiv:0911.5291]

Komatsu et al. [arXiv:0803.0547]

Tereno et al. [arXiv:0810.0555]

Elgaroy and Lahav [arXiv:0606007]

Seljak et al. [arXiv:0604335]

Brandbyge & Hannestad [arxiv:0812.3149]

Saito et al [arxiv:0907.2922]

Galaxy Clustering

Thomas, Abdalla & Lahav (In Prep. (v. soon))

Neutrino Experiments

NEMO [arXiv:0810.5497]

KATRIN Contact: [email protected]


Thank You for Listening!:)

Shaun Thomas: UCL

Simulation - testing the code by reconstructing input cosmologyEvaluated the previous DR4 release which was consistent with Blake et al. (MegaZ DR4)

1,2

1,3

1,4

2,3

Shaun Thomas: UCL

2,4

3,4

Shaun Thomas: UCL

Shaun Thomas: UCL

Mixing matrix profile

Little correlation between multipole bands introduced by partial sky after binning

Shaun Thomas: UCL

Excess Power

€

σ(Cl ) = 2f sky (2l +1) Cl + ΔΩ

N ⎛ ⎝ ⎜

⎞ ⎠ ⎟

€

σ(Cl ) = 2f sky (2l +1) Cl + ΔΩ

N ⎛ ⎝ ⎜

⎞ ⎠ ⎟

€

Cl ,mpsky =

al ,m − NΔΩ( )il ,m

2

Jl ,m

− ΔΩN

€

Cl ,mpsky =

al ,m − NΔΩ( )il ,m

2

Jl ,m

− ΔΩN

€

il ,m = Yl ,m* dΩ

ΔΩ∫

€

il ,m = Yl ,m* dΩ

ΔΩ∫

€

Jl ,m = Yl ,m2dΩ

ΔΩ∫

€

Cl = Rl ,l 'Cl 'l '∑

€

Cov Cli ,Cl

j( ) = 2fsky (2l +1)

Cli, j( )

2

€

Cov Cli ,Cl

j( ) = 2f sky (2l +1)

Cli, j( )

2

Shaun Thomas: UCL

weighing neutrinos including the largest photometric galaxy survey: megaz dr7

Documents

shaun thomas

clustering of matter

neutrinos arxiv

abdalla lahav

new sdss galaxy

largest galaxy surveys

growth of matter structure

combined neutrino constraint