Exploring the metal-poor inner Galaxy with the survey · 3/26/2019 · A. Arentsen - OCA seminar, Nice, March 26, 2019 Exploring the metal-poor inner Galaxy with the survey With:

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


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


B/P Bulges: deformed bars

Wegg & Gerhard (2013)Martinez-Valpuesta+06


Data: BRAVA survey (Howard+08,09)

Model: Shen+10

Cylindrical rotation

Kinematics: room for a classical bulge?


Metallicity distribution

�8

Metallicity Distribution Function (MDF) in the ARGOS red clump survey (Ness+2013)


ARGOS [Fe/H] < −1.0 (MP)

What about the metal-poor component?

Slight rotation in MP stars (?)

ARGOS data (Ness+13)


No signature of rotation in metal-poor BRAVA RR Lyrae stars

(Kunder+16)

What about the metal-poor component?


Model with ARGOS/APOGEE data

Chemodynamical modelling of the Galactic Bulge and Bar (Portail+2017)

�11


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


Beers & Christlieb 2005

[Fe/H] = log(Fe/H)⇤ � log(Fe/H)�

Metal-poor stars


Fraction of CEMP ([C/Fe] > +0.7) stars(Lee+13)



Metal-poor stars




[Fe/H] 0−1−2−3−∞

Starkenburg+17a

CaHK filter @ CFHT

Metal-poor stars with Pristine


Starkenburg+17a

With SDSS photometry & CaHK




With Gaia DR2 photometry & CaHK


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


Very few stars!

~150 stars [Fe/H] < -2.5 9 stars [Fe/H] < −3.0

�19





Almost no CEMP stars (3%)! In the halo it is ~27% for stars with [Fe/H] < −2.0

�20





Comparison of the Pristine and SkyMapper filters

SkyMapperPristine

�21


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)


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


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]




APOGEE


�24



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]




APOGEE


�25



~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


Teff, logg, [Fe/H] and [C/Fe]

(3 stars of similar Teff, log g and S/N)



Radial velocities, metallicities (& some abundances?)

(3 stars of similar Teff, log g and S/N)



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


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


�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



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]


�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 closer look at the selection

�34


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]



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]



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]



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)


- 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)


extinction map)


- 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


extinction map)


- 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


extinction map)


Kinematics of the Pristine stars

�42


�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


�43



MDF



�44

ARGOS ([Fe/H] < −1) (Ness+13)



�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

)



[]

�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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)



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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)





[]

�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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)



[]

�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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)



−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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)




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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)



[]

�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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)



[]

�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)


100

150

200

Vel

ocity

disp

ersi

on(k

m/s

)




Kinematics of the Pristine stars: rv dispersion

Johnson+13 (3 outer bulge fields) Ness+13 (ARGOS fields)


�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)


➤ 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


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)


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

Documents

Exploring the metal-poor inner Galaxy with the survey · 3/26/2019 · A. Arentsen - OCA seminar, Nice, March 26, 2019 Exploring the metal-poor inner Galaxy with the survey With: