SN Ia Rate Dependence on Host Galaxy Properties in Subaru SXDS and Implications for Delay Time Distribution

Jun Okumura (Kyoto Univ.)

Tomonori Totani (Kyoto Univ), Yutaka Ihara (Tokyo Univ.), Tomoki Morkuma (NAOJ), Mamoru Doi (Tokyo Univ.),

Naoki Yasuda (IPMU)

Delay Time Distribution (DTD)

• SNe Ia are expected to have a wide range of delay times from star formation to supernova explosions, and the DTD can be used to discriminate the the proposed progenitor models

early type late type

Mannucci+05

Delay Time Distribution (DTD)

• SNe Ia are expected to have a wide range of delay times form star formation to supernova explosions, and the DTD can be used to discriminate the the proposed progenitor models

- DD : the delay times is mainly determined by the from the formation of a DD binary to a merger after angular momentum loss by gravitational wave radiation

- power-law like DTD

tGW

Delay Time Distribution (DTD)

• SNe Ia are expected to have a wide range of delay times form star formation to supernova explosions, and the DTD can be used to discriminate the the proposed progenitor models

- DD : the delay times is mainly determined by the from the formation of a DD binary to a merger after angular momentum loss by gravitational wave radiation

- power-law like DTD

tGW

tIa ∼ tGW ∝ a4 a : separation

fsep(a) ∝ aβ

fD ∝ fsep(a)da

dtIa∝ t−(3−β)/4

Ia

Delay Time Distribution (DTD)

• SNe Ia are expected to have a wide range of delay times form star formation to supernova explosions, and the DTD can be used to discriminate the the proposed progenitor models

- SD : the delay time is essentially determined by the main-sequence lifetime of the secondary star in a binary

- some characteristic secondary mass scales preferred for successful SN Ia events

Totani+08• measured the SN Ia DTD in a delay time range of

0.1-8.0 Gyr by using faint variable objects detected in Subaru/XMM-Newton Deep Survey (SXDS)

• passive galaxy sample (already formed 90% of stars)

> delay time can be approximated by stellar age

• 65 SN candidates showing significant spatial offset fromthe nuclei of the host galaxies

• Power-law DTD at ~0.1-10Gyr

DTD ∝ t−1

Totani+08• measured the SN Ia DTD in a delay time range of

0.1-8.0 Gyr by using faint variable objects detected in Subaru/XMM-Newton Deep Survey (SXDS)

• passive galaxy sample (already formed 90% of stars)

> delay time can be approximated by stellar age

• 65 SN candidates showing significant spatial offset fromthe nuclei of the host galaxies

• Power-law DTD at ~0.1-10Gyr

DTD ∝ t−1

< tIa >=� tga0 tIaψ(tga − tIa)fD(tia)dtIa� tga

0 ψ(tga − tIa)fD(tIa)dtIa

DTD and Ia progenitor

- consistent with generic DTD features of DD models

- in SD case, observed DTD strongly constrain the parameter space of SD models

This Work• In Totani+08, only passive galaxies were selected and SN

Ia candidate were picked up as transient having significant offset so that DTD can be measured safely

> Motivation: would like to examine the DTD including all types of galaxies using SN Ia sample identified by LC fitting

• the correlation between SN Ia rate and host properties

• Investigate the correlation between SN Ia rate and host galaxy properties (SSFR, stellar mass, SFR) and test various DTD models/functions

This Work• In Totani+08, only passive galaxies were selected and SN

Ia candidate were picked up as transient having significant offset so that DTD can be measured safely

> Motivation: would like to examine the DTD including all types of galaxies using SN Ia sample identified by LC fitting

• the correlation between SN Ia rate and host properties

• Investigate the correlation between SN Ia rate and host galaxy properties (SSFR, stellar mass, SFR) and test various DTD models/functions

Mannucci+05Nearby (~100Mpc)

Sullivan+060.2 < z < 0.75

SXDS Data - Galaxy- wide (~1deg^2)

- multi-wavelength surveyoptical: B,V,Rc,i’,z(Subaru/Suprime-Cam)NIR: J, K (UKIDSS survey)IR: 3.6μm, 4.5μm (Spitzer/IRAC)X-ray: 0.5-2.0, 2.0-100keV (XMM-Newton)

• ~10 epochs during 2002/09-2005/09

• hyperz code

> SFH, stellar mass, Av

• > 69159 galaxieswave length

flu

x

Rc, i�, 3.6µm detection (mlim = 27.7, 27.7, 23.1)

SNe sample (Ihara+10, in prep)

• photometrically confirmed 46 SNe Ia (0.2 < z < 1.3)

- Light curve fitting with Hsiao+08 template

- in our galaxy sample > 39 SNe Ia Free parameter:• maximum brightness• stretch• redshift

testing DTD models• Power-law DTD

- Totani+08 DTD

- Pritchet+08 DTD

- index -1.5 DTD

• A+B model (Scannapieco & Bildsten 05)

SNR = AMtot(t) + Bψ(t)delayed prompt

DTD ∝ t−0.5(Pritchet + 08)

DTD ∝ t−1.08(Totani + 08)

Maoz+10

SNR =� t

0ψ(t�)DTD(t− t�) dt�

A = 8.4 [10−14yr−1 M−1⊙ ]

B = 9.4 [10−4M−1⊙ ]

Rate Calculation

• control time (CT) : detectable time of SN Ia

• SNR: Suprenova rate

- SN rate can be affected by dust extinction- photo-z Av (might be an overcorrection)- tried to see how extinction can affect the SN rate for

two extreme case (w/o extinction, photo-z Av)

0

10

20

30

40

50

60

70

0.2 0.4 0.6 0.8 1 1.2 1.4

cont

rol t

ime

[day

]

redshift

Av 0.0Av 0.2Av 0.4Av 0.6Av 0.8Av 1.0Av 1.2Av 1.4Av 1.6Av 1.8Av 2.0

con

trol

tim

eredshift

SNR =Nobs

Σ CTi(z,AV )

Observation

Why extinction ?

result - stellar massSN

Ia R

ate

stellar mass

A+B Power-law DTD

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

8 8.5 9 9.5 10 10.5 11 11.5 12

LOG

SN

Ia ra

te p

er g

alax

y [y

r-1]

stellar mass [Msun]

w/ extinctionw/o extinction

This WorkSullivan+06

Neil+06Scannappieco ildsten 05

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

8 8.5 9 9.5 10 10.5 11 11.5 12LO

G S

N Ia

rate

per

gal

axy

[yr-1

]

stellar mass [Msun]

w/ extinctionw/o extinction

Totani+08 DTDPritchet+08 DTD

index -1.5 DTD

result - SFRSN

Ia R

ate

SFR

A+B Power-law DTD

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5

LOG

SN

Ia ra

te p

er g

alax

y [y

r-1]

LOG SFR [Msun yr-1]

w/ extinctionw/o extinction

This WorkSullivan+06

Neil+06Scannappieco ildsten 05 -4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5LO

G S

N Ia

rate

per

gal

axy

[yr-1

]

LOG SFR [Msun yr-1]

w/ extinctionw/o extinction

Totani+08 DTDPritchet+08 DTD

index -1.5 DTD

result - SSFRSN

uM

SSFR

A+B Power-law DTD

-14

-13.5

-13

-12.5

-12

-11.5

-11

-10.5

-13 -12 -11 -10 -9 -8LO

G S

NuM

[yr-1

Msu

n-1]

LOG SSFR[yr-1]

w/ extinctionw/o extinction

Totani+08 DTDPritchet+08 DTD

index -1.5 DTD-14

-13.5

-13

-12.5

-12

-11.5

-11

-10.5

-13 -12 -11 -10 -9 -8

LOG

SNu

M [y

r-1M

sun-1

]

LOG SSFR[yr-1]

w/ extinctionw/o extinction

This WorkSullivan+06

Neil+06Scannapieco ildsten 05

conclusion• the correlation between SN Ia rate and host galaxy

properties is confirmed at z=0.2-1.3

• extinction correction can affect the SN rate estimates significantly and must be carefully taken into account

• Totani+08 DTD is consistent with the data within the uncertainty of extinction, but Pritchet DTD seems to be shallow in SSFR-SNuM plot

• A+B model is also consistent with the data, but the AB values are significantly different among different samples/papers