planck!early!results: thepower spectrumof!cib anisotropies · dn/ds: dusty, star-forming galaxies...

Planck Early Results:The power spectrum of CIB

Anisotropies

On behalf of the Planck collabora?on

G. Lagache, IAS, France

Origins of CIB anisotropies

Planck Conference 2011 CIB anisotropies G. Lagache

Extragalac?c-‐sources confusion: our « business »

Spitzer 24 µm Spitzer 160 µm BLAST 500 µm

Resolved CIB: 80% Resolved CIB: 15% Resolved CIB: <1%

In the far-‐IR, submm and mm:⇒ Maps of diffuse emission: a web of structures, characteris?c of CIBanisotropies⇒ P(D) analysis, stacking of known popula?ons, angular power spectra

Images from M. Béthermin

CIB mean and anisotropies redshi] distribu?ons


Lagache+2004, Béthermin+2011

CIB: Shot Noise: Sampling of a background composed of a finitenumber of sources

Longer wavelengths probe to higher redshifts

857 545 353 217

Angular power spectrum of CIB anisotropies


A white-‐noise component due to shot noise+

A correlated component due to spa?al correla?ons between the sources of the CIB

• Correlated anisotropies:• Expected to trace large-‐scale structures• Probe the clustering proper?es of dusty, star-‐forming galaxie• Constrain the rela?onship between dusty galaxies and dark ma`er distribu?on• Small scales: « 1 halo », Large scale: « 2 halos »

• Current measurements of correlated CIB anisotropies:• «Low» redshi]s: 1875 GHz (Spizter) and 3000 GHz (IRIS/IRAS)• «Mid» redshi]s: 600, 857, 1200 GHz (Blast, SPIRE)• «High» redshi]s: 150 and 220 GHz (ACT, SPT)

• Surveys size, angular resolu?on => probe different clustering regimes• Measurements equally consistent with an Halo Occupa?on Distribu?on model, apower-‐law correla?on func?on or a scale-‐independent, linear bias.

Grossan+2007, Lagache+2007, Viero+2009, Penin+2011, Amblard+2010, Dunkley+2010, Hall+2010

The power spectrum of CIB anisotropies with Planck/HFI


• What can bring Planck:• At least 4 frequencies, 857, 545, 353 and 217 GHz• The best measurement at large scales (θ>5-‐10 arcmin, l<2000)• w.r.t. SPIRE/SPT-‐ACT: high gain at low l and smaller/higher freq• Combined with IRAS, measurements from «low» to «high» redshi]s at l<3000

• Planck Early Paper (astroph 1101.2028)1) Selected fields and component separa?on

=> Bright sources removal, Galac?c dust, CMB2) Components of residual HFI maps power spectra

=> Instrumental: beam, instrument noise,=> Astrophysical: clustering, shot noises=> Addi?onal correc?ons linked to CMB removal

3) Angular power spectrum es?ma?on4) Overview and comparison with previous works

=> CIB mean and anisotropies spectral energy distribu?on=> Comparison with SPT and Blast=> Clustering of high-‐z dusty galaxies => see the presentaMon by Olivier Doré

The power spectrum of CIB anisotropies with Planck/HFI


• What can bring Planck:• At least 4 frequencies, 857, 545, 353 and 217 GHz• The best measurement at large scales (θ>5-‐10 arcmin, l<2000)• w.r.t. SPIRE/SPT-‐ACT: high gain at low l and smaller/higher freq• Combined with IRAS, measurements from «low» to «high» redshi]s at l<3000

• Planck Early Paper (astroph 1101.2028)1) Selected fields and component separa?on

=> Bright sources removal, Galac?c dust, CMB2) Components of residual HFI maps power spectra

=> Instrumental: beam, instrument noise=> Astrophysical: clustering, shot noises=> AddiFonal correcFons linked to CMB removal

3) Angular power spectrum esFmaFon4) Overview and comparison with previous works

=> CIB mean and anisotropies spectral energy distribu?on=> Comparison with SPT and Blast=> Clustering of high-‐z dusty galaxies => see the presenta6on by Olivier Doré

1) Selected fields and component separa?on


• Two contaminants: CMB (background) and Galac?c dust (foreground)

• Component separa?on based on templates removal

• Planck/HFI 143 GHz map for the CMB (wiener-‐filtered)

• HI GBT data for Galac?c dust (MarMn+2011)

• 6 high Galac?c la?tude fields for a total

of 140 Sq. Deg.

Very low dust contamina?on

<N(HI)>= 0.7 – 1.8 1020 at/cm2

217 GHz 353 GHz 545 GHz 857 GHz

1) Component separa?on: removing galac?c dust


HI: best tracer of dust emission in the diffuse sky• HI data in each field: different velocity components (local, IVC, HVC)

• Model: Planck/HFI at each ν

SP Local IVC 857 GHz from HI 857 GHz HFI

AG IVC HVC 857 GHz from HI 857 GHz HFI

(See astroph 1101.2036)

1) Component separa?on: residual power spectra


Total Total - CMB Total - CMB - dust

1) Component separa?on: residual maps


Raw maps – CMB– ERCSC point sources

HFI « raw » maps26.4 Sq. Deg.

CIB maps = Raw maps – CMB– ERCSC point sources– Galactic dust

CIB maps @ 10 arcmin

217 GHz 353 GHz 545 GHz 857 GHz


1) Component separa?on: residual maps

2) Components of residual HFI maps power spectra


Instrumental components

Beam window FunctionEffective beam computed with:- FICSBell (Hivon+2011)

- one beam- FEBeCoP (Mitra, Gorski+2010):

- one beam per field



Instrumental components

Beam window FunctionEffective beam computed with:- FICSBell (Hivon+2011)

- one beam- FEBeCoP (Mitra, Gorski+2010):

- one beam per field

Instrument NoiseJack-Knife difference maps- Ring half 1 and 2- Half focal plane- Survey I and II

Very high S/N

Instrument noise



Astrophysical components

Shot Noise:

Scut given by the ERCSC flux limit in our fields

dN/dS: Dusty, star-forming galaxies (Béthermin+2011), Radio galaxies (De Zotti+2005)

3) Angular power spectrum es?ma?on


• POKER (Ponthieu,Grain+2011): Adapta?on of the pseudospectrum techniquedevelopped for CMB analysis (MASTER, Hivon+02) to the flat sky approx

• Sta?s?cal uncertain?es: Simula?on/Analysis pipeline:

• Simula?ng maps given an input power spectrum (CIB, noise and CMB residual)and maps of dust template residuals (conserva?ve Gaussian random frac?onsof the templates).

• Systema?c errors: can introduce a bias

• Small regions => Power aliasing from angular scales larger than the size of thepatch (POKER, zero-‐padding)

• Imperfect template subtrac?on

• Uncertain?es on the beam

=> A lot of details in the paper !

Combined power spectra


x2 106

x1 105

x1 103

Shot noise: not measurable

Cl shape:Remarkably similar

Modeling CIB power spectra


Mean emissivity per comoving unit volume at frequency ν and redshift z:

Computed using the dusty-galaxies evolution model of Béthermin+2011

Power spectrum of galaxies:

Constant bias model:

Halo model and Halo Occupation Distribution:

=> See the presentation by Olivier DoréPénin+2011

HFI power spectra rule out the constant bias model


Expected shot noiseShot noise if cst bias

Comparison with SPT (ACT)


SPT data from Hall+2010

SPT model (linear bias)SPT modeldivided by 2.4

SPT data points are color corrected using the CIB mean spectrum,factor 1.04

PlanckSPT

Combina?on with Blast


Blast data points are color corrected using the CIB mean spectrum,factors 1.05 at 857 GHz, 0.7 at 545 GHz

Blast data from Viero+2009

PlanckBlast

Blast model

CIB mean and anisotropies SED


ΔI / I =15%

Conclusions


First measurement of CIB anisotropies with Planckdetecting power from 10’ to 2 degrees at 4 frequencies

217, 353, 545 and 857 GHz thanks to:A very good data processing and instrument knowledge

An dedicated and accurate component separaMonA excellent control of systemaMc errors

The use of technics directly hinerited from CMB (that’s new for CIB!)A great team and a lot of hours….

HFI power spectra rule out the constant linear bias model

In our best fit 2-parameters HOD modelAt l≈2000

Half of power comes from z<0.8 at 857 GHz and z<0.9 at 545 GHz1/5 and 2/3 come from z >3.5 at 353 GHz and 217 GHz

SMll a lot to be learned…

The scientific results that we present today are a product ofthe Planck Collaboration, including individuals from morethan 50 scientific institutes in Europe, the USA and Canada

Planck is a projectof the EuropeanSpace Agency --ESA -- withinstrumentsprovided by twoscientificConsortia fundedby ESA memberstates (inparticular the leadcountries: Franceand Italy) withcontributions fromNASA (USA), andtelescopereflectorsprovided in acollaborationbetween ESA anda scientificConsortium ledand funded byDenmark.

planck!early!results: thepower spectrumof!cib anisotropies · dn/ds: dusty, star-forming galaxies...

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