correcting for peculiar velocities of type ia supernovae ... · p.-f. leget,´ m. v. pruzhinskaya,...

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Introduction Data Results Conclusions

Correcting for peculiar velocities ofType Ia Supernovae in galaxy clusters

P.-F. Leget, M. V. Pruzhinskaya, A. Ciulli, E. Gangler, Ph. Gris,L.-P. Says + SNFACTORY collaboration

Lomonosov Moscow State University, Sternberg Astronomical Institute

November 14, 2017

Seminar SAI, 14 Novembre

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Introduction

DataNearby Supernova Factory dataHost clusters dataRedshift measurement

ResultsImpact on the Hubble diagramPhysical properties of SNe Ia and their hosts in galaxy clusters

Conclusions


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Cosmology with SN IaSN Ia are standardizable candles

I ΩΛ = 0.705± 0.034 (Betoule et al. 2014)

I “luminosity distance-redshift” relationI standardization of SN Ia (Rust 1974, 1975; Pskovskii 1977, 1984;

Phillips 1993; Phillips et al. 1999; Riess et al. 1996; Perlmutter et al.1997, 1999; Wang et al. 2003; Guy et al. 2005, 2007; Jha et al. 2007)

M = MB − αX1 + βC


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Cosmology with SN IaPeculiar velocities

(from A. Ciulli)

I Is the uncertainty in the redshift negligible?(1 + zobs) = (1 + zc)(1 + zd)

I For low and intermediate redshifts (z < 0.2):I to remove all SNe with z < 0.015 from the Hubble diagram & to

add a 300–400 km/s peculiar velocity dispersion as z uncertainty(Astier et al. 2006; Wood-Vasey et al. 2007; Amanullahet al. 2010; Union 2.1)

I velocity maps of the nearby Universe (150 km/s, Hudson et al.2004; Conley et al. 2011; Betoule et al. 2014; JLA)


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Coma cluster


σV = 1038 km/s(Colless & Dunn 1996)σm = 5σV

cz ln 10

Standard methods totake into accountpeculiar velocities cannot be applied forgalaxy clusters!

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SN Ia in clusters


µ Doppler shift

Hubble lawTrue SN Ia redshiftObserved SN Ia redshift

zobs

num

bero

fgal

axie

s

Doppler shift

cluster redshift histogram

zc

∆µ

Doppler shift

Virgo, Fornax:Blakeslee et al. 1999;Radburn-Smith et al. 2004For SNe:Feindt et al. 2013; Dhawan et al.2017

How to estimate better theimpact of peculiar velocities onthe redshift measurements?

I to match the host galaxies of SNe Ia with known clusters of galaxiesI to use the host cluster redshift instead of the host galaxy redshift

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Nearby Supernova Factory data

I 145 SN Ia (CABALLOv2, 2004 – 2009; Aldering et al. 2002)I The sample contains the objects with good final references and

properly measured light-curve parameters, including quality cutssuggested by Guy et al. (2010).

I m∗B, X1, and C are estimated with the SALT2.4 lightcurve fitter(Guy et al. 2007, Betoule et al. 2014).

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4Redshift

0

10

20

30

40

50

60

70

Num

bero

fSN

e JLA

NearbySDSSSNLSHSTSNF


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Galaxy clusters

Methods for identifying the clusters:I over-density regions on the imagesI red sequence methodI diffuse X-ray emissionI Sunyaev-Zel’dovich effect

SIMBAD databaseI only clusters of galaxies

(exclude groups of galaxies)I d < 2.5 MpcI ∆z < 0.015


A1689

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Redshift calculation

σV ' 10R200H(z)→ zcler = σV√

Ngal

Simbad query

Galaxy cluster list

R200 query

SDSS DR13 query

SNF host

Literature query

yes

no

zcl, zcl,err

request

output

computation

for all

per cluster

R lit200

tttttttttttt

Rv200

tttttttttttt

Galaxy list in cluster area

Estimation of R200

R200 =

Ngal>10

Ngal<10 R200 = 1.1 Mpc

Ngal>Npaper

else

Biweight

Keep literature value

Remove duplicates

R200 =

final result


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Final matching


I d < R200

I |zhost − zcl| < 3σVc

I + X-ray→ 11 SNe

0.00 0.02 0.04 0.06 0.08 0.10z

40

41

42

43

44

45

46

log(

L50

0[e

rgs−

1 ])

300

500

700

900

1100

1300

1500

σ V[k

ms−

1 ]Xavier et al. 2013 (1.5 Mpc, σV = 500 km s−1);Dilday et al. 2010 (1.0 Mpc h−1, ∆z = 0.015)

Red sequence

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0

1

2

g−

r

SN2009hi PTF09foz SNF20060609-002

12 14 16 18 20

0

1

2 SNF20080612-003

12 14 16 18 20r

SNF20061020-000

12 14 16 18 20

SN2007nq

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X-ray emission (ROSAT)


SNF20080731-000 SN2007nq

ZwCl 1742+3306 A0119

Host clusters data. Ensemble cluster

0 1 2 3 4 5

r/R200

4

3

2

1

0

1

2

3

4

v/σV

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

g−r

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Hubble diagram

χ2 =∑(

µi(MB, α, β)− µthi

σtoti

)2

(1)

µ = m∗b −MB + αX1 − βC (2)

µ th = 5 log10 dL−5, dL =c

H0(1+zh)

∫ zc

0

dz′c√ΩΛ + Ωm(1 + z′c)3

(3)

σ toti

2= σ 2

LCi+ σ 2

z + σ 2int (4)

zc =

z cl

c

z hostc

σz =

5√

z cl 2err

z cl ln(10), if inside a galaxy cluster

5√

z host 2err +0.0012

z host ln(10), otherwise

(5)14/18

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Hubble diagram

wRMS = 0.137m (without correction); wRMS = 0.130m (with correction); p = 5.9× 10−4

wRMS = 0.130m (inside clusters); wRMS = 0.151m (outside clusters); p = 3.8× 10−1

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09zc

−0.4

−0.3

−0.2

−0.1

0.0

0.1

0.2

0.3

0.4

∆µ

SNe Ia inside clusters, before correctionSNe Ia inside clusters, after correctionSNe Ia outside clusters

0.002 0.004 0.006 0.008

zc

−2.0

−1.6

−1.2

−0.8

∆µ

SN2006X

wRMS=0.151±0.010 magwRMS=0.137±0.036 magwRMS=0.130±0.038 mag


?

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The environment of SN Ia

The influence of the environmental effects on the SN Ia intrinsicluminosity was proved in many works:

I host galaxy morphology and stellar population age (Hamuy et al.1995,1996,2000; Riess et al. 1999; Sullivan 2003; Hicken et al. 2009;Pruzhinskaya et al. 2011; Hill et al. 2016; Henne et al. 2017)

I galocentric distance (Sullivan et al. 2003; Hill et al. 2016)I star-formation rate (Sullivan et al. 2006; Neill et al. 2009; Lampeitl

et al. 2010; Sullivan et al. 2010; Smith et al. 2012; Johansson 2013)I local star-formation rate (1-3 kpc; Rigault et al. 2013; Roman et al.,

arXiv:1706.07697)I stellar mass of host galaxy (Kelly et al. 2010; Sullivan et al. 2010;

Johansson 2013)I host metallicity (Gallagher et al. 2005,2008; Howell et al. 2009)


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Physical properties of SNe Ia in clusters


Host morphology:I E/S0 (4), Spirals (7)

Highest correction:

I X1 ' 0I blue galaxiesI high local sSFRI smaller Mstellar

I r/R200 ' 0.7

−3 −2 −1 0 1X1

0.0

0.4

0.8

1.2

1.6

−0.1 0.0 0.1 0.2C

0.0

0.4

0.8

1.2

1.6

−15−14−13−12−11−10 −9log(LsSFR)

0.0

0.4

0.8

1.2

1.6

9 10 11 12log(Mstellar)

0.0

0.4

0.8

1.2

1.6

E S0 Sab Sb Sbc ScMorphology

0.0

0.4

0.8

1.2

1.6

c|∆z|

[100

0km

s−1 ]

−0.4 −0.3 −0.2 −0.1 0.0RS residuals

0.0

0.4

0.8

1.2

1.6

0.0 0.4 0.8 1.2r/R200

0.0

0.4

0.8

1.2

1.6

14.0 14.5 15.0log(M200)

0.0

0.4

0.8

1.2

1.6

-13

-12

-11

-10

log(

LsS

FR)

Conclusions

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I We studied how the peculiar velocities of SNe Ia in galaxy clustersaffect the redshift measurements by matching 145 SNFACTORY

supernovae with known clusters of galaxies.I The applied technique allowed to decrease the spread on the Hubble

diagram. For the SNe in clusters wRMS is improved from 0.137m to0.130m with p-value = 5.9× 10−4.

I The described effect influences the distance measurements in thenearby Universe (z < 0.1) and has to be taken into account in futurecosmological surveys.

I The difference in SN light curve parameters inside and outside theclusters could be fruitful avenue of investigation for futurecosmological analysis.

Thanks for the attention!

correcting for peculiar velocities of type ia supernovae ... · p.-f. leget,´ m. v. pruzhinskaya,...

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