Study the large-scale structure of the universe using galaxy clusters · 2016-11-10 · BUI VAN...

Study the large-scale structure of theuniverse using galaxy clusters

Bùi Văn TuấnAdvisors: Cyrille Rosset

Michel CrézéDirector: Volker Beckmann

Astroparticle and Cosmology LaboratoryUniversité Paris Diderot

November 10, 2016

BUI VAN TUAN (APC) Study the large-scale structure of the universe using galaxy clustersNovember 10, 2016 1 / 16

Outline

1 Scientific context

2 Planck and Euclid missions

3 Estimators of two-point correlation function

4 Simulation of random cluster catalog

5 Current results

6 Conclusion


Scientific context

Standard model of cosmology

The large-scale structure

Galaxies, cluster of galaxies, super-clusters and filaments are the largeststructures in the universe.


Planck and Euclid missions

Planck mission

Credit: ESA.

Planck is a space mission byESA. (2009 - 2013)

Mission: All-sky CMB surveyusing millimeter wavelengths;Primordial universe (inflation)and dark universe.

Euclid mission

Credit: ESA.

Launch date: 2020.

Mission: galaxy surveys (1.5billions galaxies) for studyingthe dark universe using visibleand near infra-red wavelengths.


Estimators of two-point correlation function

Data: Planck SZ cluster catalog

Sunyaev-Zel’dovich effect

Credit: Roman’s these



Data: Planck SZ cluster catalog

Planck Sunyaev-Zel’dovich cluster catalog (1271 clusters) and thePlanck mask map (white area)

Planck SZ cluster catalog




Measure the excess probability respect to the uniform distribution offinding a galaxy in a sphere area S(θ) at an angular separation θ fromanother galaxy.

Peebles & Hauser (1974):

1 + w1(θ) =DD

RR(1)

Davis & Peebles (1983):

1 + w2(θ) =DD

DR(2)

Landy and Szalay (1993):

wLS(θ) =DD − 2DR + RR

RR(3)


Simulation of random cluster catalog

Random galaxy cluster catalogs

- Apply the Planck mask to random uniform clusters.- Each random cluster has angular size θs that corresponds to a noise mapσy500 (32 noise maps of θs from 0.94 to 35.32 arcmin)- Keep clusters have generated y > 4 ∗ σy500.

Generated θs and y500

0 5 10 15 20 25 30 35θs

0.00

0.01

0.02

0.03

0.04

0.05

y500

Planck's ts and y500Generated ts and y500


Simulation of random cluster catalog

Random galaxy cluster catalogs

Random uniform cluster catalog

Random uniform catalog

Random cluster applied Planck mask and selection function

Random uniform with Planck maskapplied and selection function


Current results

Angular distance of pairs statistics

0 20 40 60 80 100 120 140 160 180θ [degrees]

0.018

0.019

0.020

0.021

0.022

0.023

0.024

0.025Planck

Random uniform

Planck and random uniform with mask applied and selection function

Fake data and Random uniform both with mask applied and selection function


Current results

Estimators of Planck catalog and random catalogs

Correlation function of Planck catalog and random catalogs withPlanck mask applied and selection function.

0 20 40 60 80 100 120 140 160 180Angular distance [degrees]

0.10

0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

Est

imato

r tw

o-p

oin

t co

rrela

tion f

unct

ion

Estitmators of Planck and random uniform catalogs applied maskand selection function

wDD/RR

wDD/DR

wLS

σwDD/RR

σwDD/RR

σwLS


Current results

Comparing 3 estimators

Fake cluster catalog and random cluster catalogs, both with the Planckmask applied and selection function.


Current results

Comparing 3 estimators

Planck cluster catalog and random catalogs with the Planck mask appliedand selection function


Current results

Expect for detection of Baryon acoustic oscillations

– Acoustic wave propagating in the early universe due to thecounteracting forces of radiation pressure and gravity.

– The standard ruler for length scale in cosmology.

– Study the dark energy by constraining cosmological parameters.

(SDSS) - Eisenstein et al., 2005 (SDSS) - G. C. Carvalho et al., 2015


Current results

Expect for detection of Baryon acoustic oscillations

– Acoustic wave propagating in the early universe due to thecounteracting forces of radiation pressure and gravity.

– The standard ruler for length scale in cosmology.

– Study the dark energy by constraining cosmological parameters.

(SDSS) - Eisenstein et al., 2005

0.0 0.2 0.4 0.6 0.8 1.00

20

40

60

80

100

120

140Redshift distribution of 926 Planck MMF3 clusters


Current results

Ongoing work: Two-point correlation at smaller scale

High correlation around 10 degrees -> Expect to find the BAO signal


Conclusion

High correlation of clusters at small angular scale.

The distribution of Planck cluster catalog produce significant signalfrom the departure of the uniform distribution.

The DD/DR estimator has the smallest dispersion, then following bythe estimator DR, and the Landy-Szalay estimator respectively.

Expect for the detection of BAO signal at angular scale around 10degrees.


Conclusion

Future work

Estimating the angular correlation function with Euclid requires manysteps (as work was needed to produce the Planck cluster catalog) :

Calibrate and clean images

Find galaxies in images and measure their photometry

Measure their distances (or redshift) using spectroscopic andphotometric redshift methods.

Identify clusters


Conclusion

Thank you for your attention!


Study the large-scale structure of the universe using galaxy clusters · 2016-11-10 · BUI VAN...

Documents

Transcript of Study the large-scale structure of the universe using galaxy clusters · 2016-11-10 · BUI VAN...