Abundance analysis on Late G giants

—59 stars of Xinglong Planet search sample

Yujuan Liu( 劉玉娟 ) NAOC/NAOJAndo H., G. Zhao,

Sato Bun’ei, Takeda Y.,

Contents• Introduction of purpose of this work• Sample observation and reduction• Stellar parameters and kinematic parameters• Surface chemical compositions analysis

Host Stars’ Metallicity--dwarfMore planets around more metal-rich starsNo planets around metal-poor (-2<[Fe/H]<-0.8) stars so far

Fisher et al. 2005

Host Stars’ Metallicity--giants• About 20 candidates around giants, more than half of them are under solar metallicity• Pasquini et al. 2007 blue line- 14 giants red dashed line--dwarfs

The giants show a distribution shifted to lower metallicity by about 0.2-0.3 dex withrespect to the dwarf.

Takeda et al. 2008

Since the small number of detected planets around giants, this statistics results remain unclear.

Lack of giants with [Fe/H] > 0.2

Soubiran et al. 2008 (891 sample)

Takeda et al. 2008 (322 sample)Metallicity distribution of thin disk clump giants of the local (filled) and distant sample (red line)

Red giants Branch

• CNO cycle: C decrease N increase O decrease or unchanged• NaNe cycle: Na increase

When the star moves towards RGB, the nucleosynthesis products penetrate into the atmosphere due to first dredge-up phase, changing the surface abundance of Li, C, N, O and Na. The effect depends both on the stellar mass and metallicity.

Mishenina et al. (2006)-177 RCG

Na

C deplete 0.28 dex N overabundance 0.21 dex

O no changeNa overabundance 0.1dex

Luck et al. 2007-298 giants

• C depleted

• O unaffected

Purpose of this work

• Establish stellar parameters and kinematic parameters

• Determine surface chemical compositions, focusing on C, O, Na

• Find super metal-rich stars ([Fe/H]>0.2)

Observational Data Sample selection B-V: 0.6-1.0 Mv: -3 -- 2.5 V: 6 δ: >-20° Data Observation HIDES attached to OAO R=67000 wavelength coverage: 44 stars 5000-6200 15 stars 4000-7500 S/N: 100-250

Data reduction IRAF: bias subtraction, flat-fielding, scattered-light subtraction, spectrum extraction, wavelength calibration, continuum normalization EW: fitting by a Gaussion function--SPSHOW program developed by Takeda et al. 2005

Stellar Parameters-Teff Effective temperature – (B-V) color index and [Fe/H] from empirical calibration of Alonso et al. (1999) E(B-V)s --Schlegel et al. (1998)

( ) , ( ) 0.10

0.10 0.65[ ( ) 0.10], ( ) 0.10( ) S s

s s

E B V E B VA E B V E B V

E B V

•For nearby stars

( ) ( ) [1 exp( sin /125)]AE B V E B V d b

0.00 0.02 0.04 0.06 0.08 0.10

0

50

100

150

200

dTef

f

E(B-V)

0.00 0.02 0.04 0.06 0.08 0.10-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

[Fe/

H] II-

[Fe/

H] I

E(B-V)

Stellar Parameters-Teff

E(B-V) can be acceptable

Stellar Parameters-logg Surface gravity log(g/g⊙) = log(M/M⊙) + 4 log(Teff/Teff⊙) + 0.4(Mbol - Mbol⊙) where ： Mbol = V + BC - 5 logπ + 5-Av Av = 3.1E(B-V)Mass– evolution track of Yonsei-Yale (Yi et al. 2003) within 0.3 M ⊙ difference with those from Giradi (2000)---Liu et al. 2007

Stellar Parameters-Vt Microturbulent velocities were calibrated by forcing different Fe I lines with 10< EW <120 mÅ give a uniform iron abundance value. Finally, the whole procedure of determination of Teff, logg and metallicity was repeated until the final metallcity from the equivalent width calculation was full consistency with input [Fe/H] within 0.01 dex.

Ionization equilibrium test

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3-0.4

-0.2

0.0

0.2

0.4

[Fe/

H] II-[F

e/H

] I

[Fe/H]

4500 4600 4700 4800 4900 5000 5100 5200 5300-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

[Fe/

H] II-[F

e/H

] I

Teff (K)

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

[Fe/

H] II-[F

e/H

] I

log g (cm s-2)

Ionization equilibrium test

4600 4700 4800 4900 5000 5100 5200 5300 54004600

4700

4800

4900

5000

5100

5200

5300

5400

T eff(K

) (ot

hers

)

Teff

(K) (this study)

1.0 1.5 2.0 2.5 3.0 3.5 4.01.0

1.5

2.0

2.5

3.0

3.5

4.0

log

g(cm

s-2) (

othe

rs)

log g(cm s-2) (this study)

◊ Brown et al. 1989 (7 stars)○ Mishenina et al. 2006 (4 stars)∆ Luck et al. 2007 (4 stars)

stellar parameter consistency check with literatures

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

[F

e/H

] (ot

hers

)

[Fe/H] (this study)

[Fe/H] 0.05 dex higher than literature

Stellar parameters with Takeda 2008

4400 4600 4800 5000 5200 5400 5600 5800 6000

1.2

1.6

2.0

2.4

2.8

3.2

3.6

4.0

(a)

log

g(cm

s-2)

Teff

(K)

4400 4600 4800 5000 5200 5400 5600 5800 6000-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

[Fe/

H]

Teff

(K)

(b)

Stellar parameters with Takeda 2008

1.0 1.5 2.0 2.5 3.0 3.5 4.00.5

1.0

1.5

2.0

2.5

3.0

3.5

V

t (K

m s

-1)

log g(cm s-2)

(c)

Stellar parameters with Takeda 2008

0 2 4 64400

4600

4800

5000

5200

5400

5600

5800

6000

T eff (K

)

M/Msun

(a)

0 2 4 6-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

[Fe/

H]

M/Msun

(c)

Error analysis(HD47366, Teff=4834,logg=2.76,vt=1.3,[Fe/H]=-0.01)

Δ Teff(+100K)Δ Logg (0.1)

Δ[Fe/H] (0.1) Δvt(0.3kms-1)

tot

Δ[Fe/H] 0.08 0.01 0.02 -0.08 0.12Δ[Fe/H]II -0.06 0.05 0.04 -0.08 0.12Δ[C/FeII] -0.01 -0.01 -0.04 0.07 0.09Δ[O/Fe] -0.09 0.03 0.02 0.08 0.13Δ[Na/Fe] 0.02 -0.02 -0.01 0.02 0.04Δ[Si/Fe] -0.07 0.01 0.00 0.05 0.09Δ[Ca/Fe] 0.04 -0.03 -0.01 -0.04 0.07Δ[Ti/Fe] 0.07 -0.01 0.00 0.01 0.07Δ[Cr/Fe] 0.03 -0.02 -0.02 0.01 0.04Δ[Ni/Fe] -0.03 0.00 0.00 -0.01 0.03Δ[Y/Fe]II 0.08 -0.01 0.00 0.05 0.09

Kinematic parameters

6 8 100.0

0.1

0.2

0.3

0.4

ecce

ntric

ity

Rg

-250 -200 -150 -100 -50 0 500.0

0.2

0.4

0.6

0.8

1.0

Z max

VLSR

thin diskthick diskHalo

5268

21665

22799

Most stars belong to thin disk.

Thick disk stars—higher eccentricity

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.30

20

40

60

80

100

VLS

R(k

m s

-1)

[Fe/H]1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

0

20

40

60

80

100

VLS

R(k

m s

-1)

M/MSUN

Thick disk stars—higher space velocity —low mass (old stars)

-0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

[O/F

e]

[O/Fe]6300

● O 6363Δ O 5557

Abundance Analysis

[O/Fe]6300= -0.02±0.04 dex + [O/Fe]6363

Abundance AnalysisO5577-- O6300

-0.3 -0.2 -0.1 0.0 0.1 0.2

-0.4

-0.3

-0.2

-0.1

0.0

0.1

[O/F

e]55

77-[O

/Fe]

6300

[Fe/H]

SD=0.05

[O/Fe]6300= 0.08±0.05 dex + [O/Fe]5577

CarbonCarbonOxygenOxygen

C depleted O remain unaffected

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

[O/F

e]63

00

[Fe/H]

-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

[C/F

e]

[Fe/H]II

-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

[O/F

e]50

57

[Fe/H]

Sodium

-0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4-0.2

0.0

0.2

0.4

0.6

0.8

[Na/

Fe]

[Fe/H]

Na overabundance 0.1 dex

C,O,Na with Mass

1 2 3 4 5-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

[O/F

e]

M/Msun

1 2 3 4 5-1.0-0.9-0.8-0.7-0.6-0.5-0.4-0.3-0.2-0.10.00.10.20.30.40.50.6

[C

/Fe]

M/Msun

1 2 3 4 5-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

[Na/

Fe]

M/Msun

Si,Ca

-0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Si/F

e]

[Fe/H]-0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Ca/

Fe]

[Fe/H]

Ti, Cr

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Ti/F

e]

[Fe/H]-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Cr/F

e]

[Fe/H]

Ni, Mn

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Ni/F

e]

[Fe/H]-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Mn/

Fe]

[Fe/H]

Ce,Y

-0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Y/F

e]

[Fe/H]II

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Ce/

Fe]

[Fe/H]II

Sc

-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

[Sc/

Fe] II

[Fe/H]II

Remind problems Abundance from O 5057 maybe not

correct

Conclusion Stellar parameter lie in the main group of Takeda et al. 2008, lack of stars [Fe/H]>0.2 Most sample belong to thin disk stars C depleted 0.13 dex(-0.1<[Fe/H]<0.1) O remain unaffected Na overabundance 0.1 dex The effect dependt on [Fe/H] and Mass. Other elements remain unaffected, consisting with results of Takeda et al. (2008) Consist with theoretical results