A Method for Obtaining Detailed Abundances of Extragalactic Globular Clusters w/ Andy McWilliam (Carnegie Obs.) Scott Cameron, Janet Collucci (UM) QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. MW- 47Tuc NGC 5128 LMC- NGC 2005
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A Method for Obtaining Detailed Abundances of Extragalactic Globular Clusters
A Method for Obtaining Detailed Abundances of Extragalactic Globular Clusters. LMC- NGC 2005. MW- 47Tuc. NGC 5128. w/ Andy McWilliam (Carnegie Obs.) Scott Cameron, Janet Collucci (UM). The goal: formation histories of galaxies. Galaxy #1, Milky Way: - PowerPoint PPT Presentation
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A Method for ObtainingDetailed Abundances of Extragalactic Globular Clusters
w/ Andy McWilliam (Carnegie Obs.)Scott Cameron, Janet Collucci (UM)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
MW- 47Tuc NGC 5128LMC- NGC 2005
Galaxy #1, Milky Way:
Formation: halo bulge/thick disk thin disk Evidence: abundances (Fe,O,Mg,Eu…) & kinematics (bulk, streams)
(1) Stars : *timescales*, substructure (recent: Ivans et al 2003)
The goal: formation histories of galaxies
halo thick bulge thin
Prochaska et al 2004 Yanny et al 2003
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Galaxy #1, Milky Way:
Formation: halo bulge/thick disk thin disk Evidence: abundances & kinematics
*note blends are worse!! (metal rich GC) Need to synthesize blended lines
Training Set: step 1 - isochrone CMD (4 GCs)
1- Balmer lines -
H, H, H, H EW’s
47Tuc match:
Age ≈ 10-12 Gyr[A/H] ≈ -0.9
2- FeI & FeII
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, unadjusted isochrones)
2- FeI & FeII
[FeI/H] input [A/H] input age
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, unadjusted isochrones)
2- FeI & FeII
[FeI/H] input [A/H] input age
+/-0.1 !!
at <1 Gyr: young = hot modeled lines=weak. at >1 Gyr: models not changing much
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, unadjusted isochrones)
Training Set: step 2 - isochrone CMD (47 Tuc)
FeI checks: no FeI slope w/ EP if: age > 2 & [A/H] < -1
w/ if: age > 3 w/ EW if: age > 3 Gyrs
2- FeI & FeII
[FeI/H] input [A/H] input age
+/- 0.05 !!
[FeII/H] input [A/H] input age
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, unadjusted isochrones)
Training Set: step 2 - isochrone CMD (47 Tuc)
The age-metallicity degeneracy!
2- FeI & FeII
[FeI/H] input [A/H] input age
+/- 0.05 !!
[FeII/H] input [A/H] input age
expected age to increase giant:dwarf… g … N(e-).
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, unadjusted isochrones)
2- FeI & FeII
[FeI/H] input [A/H] input age
+/-0.05 !! (statistical)
[FeII/H] input [A/H] ( N(e-)) input age
[Fe/H]=[FeII/H]:[Fe/H] -0.6age = 5-16 Gyrs
Best FeI solution: [Fe/H] -0.6(10Gyr, [A/H]=-0.68)
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, unadjusted isochrones)
Training Set: step 2 - isochrone CMD (47 Tuc)
1- iron peak
x (x) N-lines [X/Fe][Fe/H] [X/Fe] (C’04) Sc II 2.53 ... 1 +0.13 +0.13V I 3.40 0.31 5 +0.11 +0.05Cr I 4.87 0.14 3 -0.19 +0.11Mn I 4.49 0.30 4 -0.31 -0.29Fe I 6.78 0.24 71 -0.73 -0.67, -0.79 (KI’03)Fe II 6.81 0.15 8 -0.70 -0.56Ni I 5.47 0.18 12* -0.05 +0.06
Abundance results for 47Tuc!
Carretta et al 2004Kraft & Ivans 2003(Padova, 10Gyr, [A/H]=-0.68, adjusted)
Isochrone analysis (w/ mass segregation +boosted AGB dump)
CONSISTENT with solution from individual stars.
unambiguous [Fe/H]=0.7
Training Set: step 2 - isochrone CMD (47 Tuc)
(Padova, 10Gyr, [A/H]=-0.68, adjusted)
Abundance results for 47Tuc!
Training Set: step 2 - isochrone CMD (47 Tuc)
2. -elements
x (x) N-lines [X/Fe] [X/Fe] (CG04)[O I] 8.45 ... 1 +0.45 +0.23 Mg I 7.02 ... 1 +0.17 +0.40Si I 7.16 0.21 6 +0.33 +0.30Ca I 5.81 0.24 12 +0.19 +0.20Ti I 4.55 0.24 13 +0.34 +0.26Ti II 4.68 0.16 3 +0.44 +0.38
3- non-alpha, light elements
Na I 5.97 0.19 3 +0.38 +0.23 Al I 6.19 0.02 2 +0.43
(Padova, 10Gyr, [A/H]=-0.68, adjusted)
Carretta & Gratton 2004
Abundance results for 47Tuc!
Training Set: step 2 - isochrone CMD (47 Tuc)
4- neutron-capture elements (s-, r-process)
x (x) N-lines [X/Fe] [X/Fe]Y II 1.34 ... 1 -0.19 +0.49? (Brown+Wallerstein’89)
Y I: 1.29 ... 1 -0.24 Zr I 1.80 0.21 2* -0.08 -0.22?Ba II 1.41 0.09 3* -0.11 La II 0.57 0.38 2 +0.05Nd II 0.80 ... 1 +0.01Eu II -0.12 ... 1 +0.04 +0.36?
(Padova, 10Gyr, [A/H]=-0.68, adjusted)
Abundance results for 47Tuc!
Results for 47Tuc:
-elements:
Similar to halo/bulge.
Exactly as expected.
light-elements: (Na, Al)
HIGH!
Consistent with proton-burning(self-enrichment!) in GCs: NeNa, MgAl
Gratton, Sneden, Carretta 2004
halo thick bulge thin
Results on 47Tuc:halo thick bulge thin
Fe-Peak elements:
Similar to halo/bulge.
Exactly as expected.
Results on 47Tuc:
Heavy elements: (r-, s-process)
Similar to halo… close to solar.
Sites of r-process not well known.Differences in SN yields with metallicity…
Second Training Set - LMC
Important because:
1- MW GCs all age > 8 Gyrs … LMC 0.1 < Age < 5 Gyr
2- Test the standard model for chemical enrichment!
[/Fe] > 0 when metal poor, [/Fe] ~ 0 when metal rich