exploring the metal-poor inner galaxy with the survey · 3/26/2019 · a. arentsen - oca seminar,...
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A. Arentsen - OCA seminar, Nice, March 26, 2019
Exploring the metal-poor inner Galaxy
with the survey
With: Else Starkenburg (AIP), Nicolas Martin (Observatoire de Strasbourg), Kim Venn (University of Victoria), Dan Zucker (Macquarie University), Andrea Kunder (Saint
Martin’s University), Vanessa Hill (OCA), Mathias Schultheis (OCA) and the Pristine team
Anke Arentsen (AIP, Potsdam, Germany)
@Anke_NL
A. Arentsen - OCA seminar, Nice, March 26, 2019 �2
Where are the oldest stars?
Colour-coded by density Colour-coded by fraction of old stars
Starkenburg+17b
A. Arentsen - OCA seminar, Nice, March 26, 2019 �3
Where are the oldest stars?
Colour-coded by density Colour-coded by fraction of old stars
Starkenburg+17b
The Inner Galaxy
Artist Impression, Credit: ESO/NASA/JPL-Caltech/M. Kornmesser/R. Hurt
The Inner Galaxy: Boxy, Peanut-shaped Bulge with an X-Shape
Artist Impression, Credit: Anke Arentsen Background: ESO/NASA/JPL-Caltech/M. Kornmesser/R. Hurt
A. Arentsen - OCA seminar, Nice, March 26, 2019 �6
B/P Bulges: deformed bars
Wegg & Gerhard (2013)Martinez-Valpuesta+06
A. Arentsen - OCA seminar, Nice, March 26, 2019 �7
Data: BRAVA survey (Howard+08,09)
Model: Shen+10
Cylindrical rotation
Kinematics: room for a classical bulge?
A. Arentsen - OCA seminar, Nice, March 26, 2019
Metallicity distribution
�8
Metallicity Distribution Function (MDF) in the ARGOS red clump survey (Ness+2013)
A. Arentsen - OCA seminar, Nice, March 26, 2019 �9
ARGOS [Fe/H] < −1.0 (MP)
What about the metal-poor component?
Slight rotation in MP stars (?)
ARGOS data (Ness+13)
A. Arentsen - OCA seminar, Nice, March 26, 2019 �10
No signature of rotation in metal-poor BRAVA RR Lyrae stars
(Kunder+16)
What about the metal-poor component?
A. Arentsen - OCA seminar, Nice, March 26, 2019
Model with ARGOS/APOGEE data
Chemodynamical modelling of the Galactic Bulge and Bar (Portail+2017)
�11
A. Arentsen - OCA seminar, Nice, March 26, 2019
Why look for metal-poor stars in the bulge? ➤ Find the oldest (metal-poor) stars in the Galaxy ➤ Need of a larger sample of metal-poor stars to study
that component of the bulge
A. Arentsen - OCA seminar, Nice, March 26, 2019 �13
Beers & Christlieb 2005
[Fe/H] = log(Fe/H)⇤ � log(Fe/H)�
Metal-poor stars
A. Arentsen - OCA seminar, Nice, March 26, 2019 �14
Fraction of CEMP ([C/Fe] > +0.7) stars(Lee+13)
[Fe/H] = log(Fe/H)⇤ � log(Fe/H)�
Beers & Christlieb 2005
Metal-poor stars
A. Arentsen - OCA seminar, Nice, March 26, 2019 �15
Beers & Christlieb 2005
[Fe/H] = log(Fe/H)⇤ � log(Fe/H)�
[Fe/H] 0−1−2−3−∞
Starkenburg+17a
CaHK filter @ CFHT
Metal-poor stars with Pristine
A. Arentsen - OCA seminar, Nice, March 26, 2019 �16
Starkenburg+17a
With SDSS photometry & CaHK
Metal-poor stars with Pristine
A. Arentsen - OCA seminar, Nice, March 26, 2019 �17
Metal-poor stars with Pristine
With Gaia DR2 photometry & CaHK
A. Arentsen - OCA seminar, Nice, March 26, 2019
MDF in the SkyMapper/EMBLA survey (Howes+14,15,16) compared to
the ARGOS survey (Ness+13)
The metal-poor stars in the bulge
�18
A. Arentsen - OCA seminar, Nice, March 26, 2019
Very few stars!
~150 stars [Fe/H] < -2.5 9 stars [Fe/H] < −3.0
�19
MDF in the SkyMapper/EMBLA survey (Howes+14,15,16) compared to
the ARGOS survey (Ness+13)
The metal-poor stars in the bulge
A. Arentsen - OCA seminar, Nice, March 26, 2019
Almost no CEMP stars (3%)! In the halo it is ~27% for stars with [Fe/H] < −2.0
�20
MDF in the SkyMapper/EMBLA survey (Howes+14,15,16) compared to
the ARGOS survey (Ness+13)
The metal-poor stars in the bulge
A. Arentsen - OCA seminar, Nice, March 26, 2019
Comparison of the Pristine and SkyMapper filters
SkyMapperPristine
�21
A. Arentsen - OCA seminar, Nice, March 26, 2019
Pristine in the Bulge
�22
black+magenta squares = observed blue line = proposed
Using the PanSTARRS1 Bayestar extinction map
(Green+15,18)
We are limited by observing from the North (CFHT)
A. Arentsen - OCA seminar, Nice, March 26, 2019
Pristine in the bulge
�23
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8(BP-RP)
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
(Cah
k-G
) - 2
.5(B
P-R
P)
- 4
- 3
- 2
- 1
0
[Fe/
H]
Pilot photometry Pristine colour-colour plot with
spectroscopic metallicities from EMBLA, ARGOS,
APOGEE
broadband photometry from Gaia (with quality cuts)
We thank Louise Howes and Melissa Ness for sharing (part) of the EMBLA and ARGOS metallicities
A. Arentsen - OCA seminar, Nice, March 26, 2019
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8(BP-RP)
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
(Cah
k-G
) - 2
.5(B
P-R
P)
- 4
- 3
- 2
- 1
0
[Fe/
H]
Pristine in the bulge
Pilot photometry Pristine colour-colour plot with
spectroscopic metallicities from EMBLA, ARGOS,
APOGEE
broadband photometry from Gaia (with quality cuts)
�24
We thank Louise Howes and Melissa Ness for sharing (part) of the EMBLA and ARGOS metallicities
A. Arentsen - OCA seminar, Nice, March 26, 2019
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8(BP-RP)
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
(Cah
k-G
) - 2
.5(B
P-R
P)
- 4
- 3
- 2
- 1
0
[Fe/
H]
Pristine in the bulge
Pilot photometry Pristine colour-colour plot with
spectroscopic metallicities from EMBLA, ARGOS,
APOGEE
broadband photometry from Gaia (with quality cuts)
�25
We thank Louise Howes and Melissa Ness for sharing (part) of the EMBLA and ARGOS metallicities
A. Arentsen - OCA seminar, Nice, March 26, 2019
~6000 stars
AAT/AAOmega+2dF (400 fibres in 2 degree field)
R~1300 in blue arm R~10000 in red (CaT)
Low-/intermediate resolution follow-up
�26
A. Arentsen - OCA seminar, Nice, March 26, 2019 �27
Teff, logg, [Fe/H] and [C/Fe]
(3 stars of similar Teff, log g and S/N)
Low-/intermediate resolution follow-up
A. Arentsen - OCA seminar, Nice, March 26, 2019 �28
Radial velocities, metallicities (& some abundances?)
(3 stars of similar Teff, log g and S/N)
Low-/intermediate resolution follow-up
A. Arentsen - OCA seminar, Nice, March 26, 2019 �29
Full spectrum fitting of the blue spectra using the empirical MILES library with the ULySS fitting code (Koleva+09)
> Teff, logg & [Fe/H] down to [Fe/H] = −2.8
Low resolution follow-up
A. Arentsen - OCA seminar, Nice, March 26, 2019 �30
4000500060007000Te↵
0
1
2
3
4
5
log
g
�3.0 �2.5 �2.0 �1.5 �1.0 �0.5 0.0 0.5[Fe/H]
0
50
100
150
200
250
300
350
400
450
Num
ber
ofst
ars
full sample
1.0 < log g < 3.5
�2.5
�2.0
�1.5
�1.0
�0.5
0.0
0.5
[Fe/
H]
VMP MP
Low resolution follow-up
A. Arentsen - OCA seminar, Nice, March 26, 2019
�3.0 �2.5 �2.0 �1.5 �1.0 �0.5 0.0 0.5[Fe/H]
0.0
0.2
0.4
0.6
0.8
1.0
1.2R
elat
ive
num
ber
ofst
ars
Pristine
ARGOS (overlapping fields)
EMBLA
Metallicity Distribution Function of our sample
�31
We thank Louise Howes and Melissa Ness for sharing (part) of the EMBLA and ARGOS metallicities
A. Arentsen - OCA seminar, Nice, March 26, 2019 �32
Low-[Fe/H] tail and [C/Fe] are still work in progress, using the synthetic CRUMP library with FERRE (Allende Prieto+06)
> below [Fe/H] = −2.0 (down to −6.0)
Low resolution follow-up: metal-poor tail & [C/Fe]
A. Arentsen - OCA seminar, Nice, March 26, 2019
�3.4 �3.2 �3.0 �2.8 �2.6 �2.4 �2.2[Fe/H]
0
20
40
60
80
100
120
Num
ber
ofst
ars
ULySS (general method)
FERRE (VMP tail + [C/Fe])
Metallicity Distribution Function of our sample
�33
Our two methods at low [Fe/H]
PRELIMINA
RY
A. Arentsen - OCA seminar, Nice, March 26, 2019
A closer look at the selection
�34
A. Arentsen - OCA seminar, Nice, March 26, 2019 �35
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8bp_rp_0bay
- 2 . 0
- 1 . 5
- 1 . 0
- 0 . 5
cahk
_0ba
y - g
_0ba
y - 2
.5*b
p_rp
_0ba
y
- 2
- 1
0
FeH
Low extinction region (EBV < 0.2) (dereddened using PanSTARRS Bayestar extinction map)
BP - RP
CaH
K - G
- 2.
5*(B
P - R
P)
[Fe/
H]
A closer look at the selection
A. Arentsen - OCA seminar, Nice, March 26, 2019
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8bp_rp_0bay
- 2
- 1
0
cahk
_0ba
y - g
_0ba
y - 2
.5*b
p_rp
_0ba
y
- 2
- 1
0
FeH
�36
BP - RP
CaH
K - G
- 2.
5*(B
P - R
P)for regions with |b| > 7
(EBV from 0.2 - 0.5) (dereddened using PanSTARRS Bayestar extinction map)
[Fe/
H]
A closer look at the selection
A. Arentsen - OCA seminar, Nice, March 26, 2019
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8bp_rp_0bay
- 2
- 1
0
cahk
_0ba
y - g
_0ba
y - 2
.5*b
p_rp
_0ba
y
- 2
- 1
0
FeH
�37
BP - RP
CaH
K - G
- 2.
5*(B
P - R
P)for regions with |b| > 7
(EBV from 0.2 - 0.5) (dereddened using PanSTARRS Bayestar extinction map)
[Fe/
H]
A closer look at the selection
A. Arentsen - OCA seminar, Nice, March 26, 2019
0.6 0.8 1.0 1.2 1.4 1.6bp_rp_0bay
- 2 . 0
- 1 . 5
- 1 . 0
cahk
_0ba
y - g
_0ba
y - 2
.5*b
p_rp
_0ba
y
- 2 . 5
- 2 . 0
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
FeH
All follow-up: Gaia DR2 photometry
�38
[Fe/
H]
BP - RP
CaH
K - G
- 2.
5*(B
P - R
P)
(dereddened using PanSTARRS Bayestar
extinction map)
A. Arentsen - OCA seminar, Nice, March 26, 2019
- 0 . 2 0 0.2 0.4 0.6 0.8 1.0g_rPS_0bay
- 1 . 0
- 0 . 5
0
0.5
cahk
_0ba
y - g
PS_0
bay
- 2.0
*g_r
PS_0
bay
- 2 . 5
- 2 . 0
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
FeH
All follow-up: PanSTARRS DR1 photometry
�39
[Fe/
H]
g - r
CaH
K - g
- 2.
0*(g
- r)
(dereddened using PanSTARRS Bayestar
extinction map)
A. Arentsen - OCA seminar, Nice, March 26, 2019
- 0 . 2 0 0.2 0.4 0.6 0.8 1.0g_rPS_0bay
- 1 . 0
- 0 . 5
0
0.5
cahk
_0ba
y - g
PS_0
bay
- 2.0
*g_r
PS_0
bay
- 2 . 5
- 2 . 0
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
FeH
PanSTARRS DR1 photometry: efficiency
�40
[Fe/
H]
g - r
CaH
K - g
- 2.
0*(g
- r)
90% [Fe/H] < -1.070% [Fe/H] < -1.525% [Fe/H] < -2.0
(dereddened using PanSTARRS Bayestar
extinction map)
A. Arentsen - OCA seminar, Nice, March 26, 2019
- 0 . 2 0 0.2 0.4 0.6 0.8 1.0g_rPS_0bay
- 1 . 0
- 0 . 5
0
0.5
cahk
_0ba
y - g
PS_0
bay
- 2.0
*g_r
PS_0
bay
- 2 . 5
- 2 . 0
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
FeH
PanSTARRS DR1 photometry: efficiency
�41
[Fe/
H]
g - r
CaH
K - g
- 2.
0*(g
- r)
80% [Fe/H] < -1.550% [Fe/H] < -2.020% [Fe/H] < -2.5
(dereddened using PanSTARRS Bayestar
extinction map)
A. Arentsen - OCA seminar, Nice, March 26, 2019
Kinematics of the Pristine stars
�42
A. Arentsen - OCA seminar, Nice, March 26, 2019
�3.0 �2.5 �2.0 �1.5 �1.0 �0.5 0.0 0.5[Fe/H]
0.0
0.2
0.4
0.6
0.8
1.0
1.2R
elat
ive
num
ber
ofst
ars
Pristine
ARGOS (overlapping fields)
�43
We thank Louise Howes and Melissa Ness for sharing (part) of the EMBLA and ARGOS metallicities
Kinematics of the Pristine stars
MDF
A. Arentsen - OCA seminar, Nice, March 26, 2019
Kinematics of the Pristine stars
�44
ARGOS ([Fe/H] < −1) (Ness+13)
A. Arentsen - OCA seminar, Nice, March 26, 2019
Kinematics of the Pristine stars
�45
ARGOS ([Fe/H] < −1) (Ness+13)Pristine (−2 < [Fe/H] < −1)
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
Pristine −1.5 < [Fe/H] < −1.0
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
A. Arentsen - OCA seminar, Nice, March 26, 2019 �46
Kinematics of the Pristine stars
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
[]
�50
0
50
100M
ean
velo
city
(km
/s)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
−1.5 < [Fe/H] < −1.0 −2.0 < [Fe/H] < −1.5 −2.0 < [Fe/H] < −3.0
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
A. Arentsen - OCA seminar, Nice, March 26, 2019 �47
Kinematics of the Pristine stars: rotation?
(model: Shen+10 for [metal-rich] BRAVA giants)
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
b = -4 (model)
b = -6 (model)
b = -8 (model)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
[]
�50
0
50
100
Mea
nve
loci
ty(k
m/s
)
�1.5 < [Fe/H] < �1.0 (MP)
b = -4 (model)
b = -6 (model)
b = -8 (model)
+4.0 < b < +6.0
�2.0 < b < �5.0
�5.0 < b < �8.0
�8.0 < b < �11.0
[]
�2.0 < [Fe/H] < �1.5 (IMP)
[]
�3.0 < [Fe/H] < �2.0 (VMP)
�10 �5 0 5 10Galactic Longitude (degrees)
100
150
200
Vel
ocity
disp
ersi
on(k
m/s
)
�10 �5 0 5 10Galactic Longitude (degrees)
�10 �5 0 5 10Galactic Longitude (degrees)
A. Arentsen - OCA seminar, Nice, March 26, 2019 �48
Kinematics of the Pristine stars: rv dispersion
Johnson+13 (3 outer bulge fields) Ness+13 (ARGOS fields)
A. Arentsen - OCA seminar, Nice, March 26, 2019
�3.0 �2.5 �2.0 �1.5 �1.0 �0.5 0.0[Fe/H]
75
100
125
150
175
200
Vel
ocity
disp
ersi
on(k
m/s
)
-5 < b < -2
-8 < b < -5
-11 < b < -8
�49
Kinematics of the Pristine stars: rv dispersion
PristineNess+13
(ARGOS fields)
A. Arentsen - OCA seminar, Nice, March 26, 2019
➤ We can effectively select metal-poor stars in the Bulge with Pristine & Gaia/PanSTARRS
➤ Spectroscopic follow-up has been successful
Summary
�50
�3.0 �2.5 �2.0 �1.5 �1.0 �0.5 0.0 0.5[Fe/H]
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Rel
ativ
enu
mber
ofst
ars
Pristine
ARGOS (overlapping fields)
EMBLA
- 0 . 2 0 0.2 0.4 0.6 0.8 1.0g_rPS_0bay
- 1 . 0
- 0 . 5
0
0.5
cahk
_0ba
y - g
PS_0
bay
- 2.0
*g_r
PS_0
bay
- 2 . 5
- 2 . 0
- 1 . 5
- 1 . 0
- 0 . 5
0
0.5
FeH
[Fe/
H]
g - r
CaH
K - g
- 2.
0*(g
- r)
A. Arentsen - OCA seminar, Nice, March 26, 2019
Summary
�51
Work in progress!
➤ kinematics
➤ fraction of carbon-enhanced metal-poor stars
➤ study some (very) metal-poor stars in detail (select for high-res follow-up)
➤ We can effectively select metal-poor stars in the Bulge with Pristine & Gaia/PanSTARRS
➤ Spectroscopic follow-up has been successful
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