Gaia EDR3 view on Galactic globular clusters

Eugene Vasiliev

Institute of Astronomy, Cambridge 1 10 100 distance

MW-Gaia workshop, 10 February 2021 The Gaia [r]evolution

DR1 =⇒ DR2 The Gaia [r]evolution

DR1 =⇒ DR2 The Gaia [r]evolution

DR1 =⇒ DR2 =⇒ EDR3 The Gaia [r]evolution

pre-Gaia =⇒ DR1 =⇒ DR2 =⇒ EDR3 =⇒ Determination of cluster properties and membership Criteria for selecting a “clean” subset of stars: G ≥ 13; 0 RUWE < 1.15; 2 ] r y /

astrometric excess noise sig < 2; s

a 4 m

  [

ipd gof harmonic amplitude < exp 0.18 (G − 33) ; δ µ ipd frac multi peak ≤ 2; 6

visibility periods used ≥ 10; 8 ? phot bp rp excess factor < C (bp rp) + 3 C ? (G); usually only 5p sources (when have enough of them). 10 8 6 4 2 0 µα [mas/yr]

Mixture modelling approach: measurements: $, µ, R XNstars   maximize ln L ≡ ln η fmemb(xi | θmemb) + (1 − η) ffield(xi | θfield) , i=1 membership probability of i-th star: parameters of distributions η fmemb(xi ) pi = η fmemb(xi ) + (1 − η) ffield(xi ) fraction of members

Results: $, µ, σµ(R), µrot(R), η, pi ,... 1.1 Statistical uncertainties are slightly underestimated bright ⇐⇒ faint

10-1

10-2

η=1.203 η=1.165 η=1.142 η=1.188 -3 10 N=2083 N=5822 N=7253 N=8980 0

10-1

10-2

⇐⇒ η=1.087 η=1.080 η=1.077 η=1.127 -3 10 N=1043 N=5055 N=11879 N=7231 14

10-1 outskirts 10-2

η=1.108 η=1.073 η=1.041 η=1.066 -3 10 N=664 N=3679 N=9952 N=4046 20

1.30 5p, 13.0

t 1.20 5139 c

a 5272 f

n 1.15 5904 o i

t 6121 a

l 1.10

f 6205 n i

6254 r 1.05 o 6362 r r

e 6397 1.00 6752 0.95 6809 3 10 30 100 300 3 10 30 100 300 3 10 30 100 300 3 10 30 100 300 density [sources/arcmin²] Actual vs. formal uncertainty: 2 2 2 2 actual = η formal + add, error inflation factor ζ η = (1 + Σ/Σ0) , 2 Σ0 = 10 stars/arcmin , ζ = 0.04,

add = 0.01 mas. 1.1 Statistical uncertainties are slightly underestimated

1.30 5p, 13.0

t 1.20 5139 c

a 5272 f

n 1.15 5904 o i

t 6121 a

l 1.10

f 6205 n i

6254 r 1.05 o 6362 r r

e 6397 1.00 6752 0.95 6809 3 10 30 100 300 3 10 30 100 300 3 10 30 100 300 3 10 30 100 300 density [sources/arcmin²] Actual vs. formal uncertainty: Deconvolved PM dispersion profiles 2 2 2 2  = η  +  , 0.20 NGC 3201 0.20 NGC 3201 actual formal add (nominal errors) (η-scaled errors) error inflation factor 0.15 0.15 ζ

η = (1 + Σ/Σ0) , µ µ

σ 0.10 σ 0.10 2 Σ0 = 10 stars/arcmin , G ²µ G ²µ 0.05 13.0 17.0 0.03 0.05 13.0 17.0 0.03 − − 17.0 18.5 0.10 17.0 18.5 0.10 − − ζ = 0.04, 18.5 20.0 0.23 18.5 20.0 0.23 − − 0.00 0.00 add = 0.01 mas. 0 5 10 15 20 0 5 10 15 20 Radius [arcmin] Radius [arcmin] 1.2 Systematic errors are spatially correlated NGC 104 parallax G G G 0.20 0.21 0.22 0.23 0.24 13 16 18 20 13 16 18 20 13 16 18 20 30 0.24 20 0.23 10

0.22 0 parallax Y [arcmin] 10 0.21 20

0.20 NGC 104 30 30 20 10 0 10 20 30 0' < R < 10' 10' < R < 15' 15' < R < 30' X [arcmin]

NGC 5139 parallax 0.21 G G G 0.17 0.18 0.19 0.20 0.21 13 16 18 20 13 16 18 20 13 16 18 20 30 0.20 20

0.19 10

0

parallax 0.18 Y [arcmin] 10

0.17 20

NGC 5139 30 30 20 10 0 10 20 30 0' < R < 14' 14' < R < 20' 20' < R < 40' X [arcmin] 1.2 Systematic errors are spatially correlated

13

2 40 6752 s a µ

[ 50 100 20 ) θ ( 0 0 0 V

20 50 100

40 0.0 0.1 0.2 0.3 0.4 0.5 0.0 0.1 0.2 0.3 0.4 0.5 0.0 0.1 0.2 0.3 0.4 0.5 θ [deg] θ [deg] θ [deg]

Spatial covariance function: V$(θ) = ($i − $)($j − $) , where θ is the angular distance between stars i and j. see Lindegren+ 2012.03380, Ma´ızApell´aniz+ 2101.10206 ◦ for V$(θ) determined on scales θ & 1 from LMC stars and quasars. p For bright stars (13 < G < 18): $,sys ≡ V$(θ = 0) ' 0.01 mas; DR2: for fainter stars it may be ∼ 1.5 − 2× higher. $,sys ∼ 0.043 µ,sys ∼ 0.066 Same for PM: µ,sys ' 0.025 mas/yr. 1.3 [Corrected] parallaxes might be slightly overestimated

2 mean parallaxes of cluster members vs. literature distances

after applying the parallax zero-point correction from Lindegren+ 2012.01742 NGC 7492 NGC 5824 2 2 1.5 $i − 1/Di ∼ N (∆$, $,i + $,sys), Pal 11 NGC 6356 ∆$ ' 0.008 mas, NGC 6284 Pal 8 M 72 FSR 1758 Rup 106 ESO 93-8 M 54 BH 176 NGC 5634 Pal 1 M 75 NGC 6316 Terzan 8 M 53 $,sys ' 0.01 mas. NGC 6355 NGC 6287 1.2 M 62 e NGC 6934 c n M 55 NGC 6229 a t s i BH 140 n M 107 e C d

NGC 6752 M 28 M 12 M 4 NGC 6397

ω NGC 6544 × NGC 1261

1 47 Tuc M 22

NGC 3201 M 71 NGC 6352 NGC 6553 M 10 x IC 4499 NGC 6366 NGC 6426 a l l NGC 5466 a M 2 r NGC 6528 a p Pal 9 Pal 7 NGC 6540

0.8 BH 229 NGC 5053 FSR 1716

Pal 6 104 Terzan 2 Terzan 9 3 Pal 10 10 Terzan 12

0.6 102

101 number of stars 0.5

2 3 5 7 10 NGC 4147 20 30 distance [Kpc] (compilation of literature data by H.Baumgardt) 2.1 Internal kinematics: rotation, dispersion

0.6 NGC 104 (47 Tuc) NGC 288 NGC 6838 (M 71) 3.5 N=39993 (33195), D=4.5 kpc 0.08 N=4734 (241), D=8.9 kpc N=3022 (842), D=4.0 kpc 3 0.15 10 3.0

] 0.4 ] ] r r 0.06 r

y y 2.5 y ] ] ] / / / s s s

s s s 2 a a a

/ / 0.10 / σµ 5 2.0 m m m m m m

[ 0.2 [ [ k k k

[ 0.04 [ [ µ µ µ

s 1.5 s s σ σ σ o o o l l l

, , , σ σ σ t t t 0.05 1 o o o

r r 1.0 r

µ 0.0 µrot 0 µ 0.02 µ 0.5 0.00 0 0.2 0.00 0.0 5

0 5 10 15 20 25 30 35 40 0 2 4 6 8 10 12 14 0 2 4 6 8 10 R [arcmin] R [arcmin] R [arcmin]

25 NGC 5139 (ω Cen) NGC 4590 (M 68) 0.20 NGC 6681 (M 70) N=53202 (37323), D=5.5 kpc 0.10 N=3296 (148), D=10.5 kpc 5 N=852 (49), D=9.4 kpc 8 0.8 20 0.15 0.08 4 ] ] ]

r r r 6 y y y ] ] ] / / / s s s s 0.6 s 0.06 3 s a a a 15 / / / 0.10 m m m m m m [ [ [

k k 4 k

[ [ [ µ µ µ 0.04 2 s s s σ σ σ o o o l l l 0.4

, 10 , , σ σ σ t t t

o o o 0.05 r r 0.02 1 r 2 µ µ µ

0.2 5 0.00 0 0.00 0 0.02 1 0.0 0 0 5 10 15 20 25 30 35 40 0 2 4 6 8 10 12 14 0 1 2 3 4 5 6 R [arcmin] R [arcmin] R [arcmin] Good agreement with HST σµ [Watkins+ 2015, Cohen+ 2021] and σLOS from literature 2.2 Dynamical distance determination

20 0.12 NGC_6362 old D=7.62 0.05 10 ± new D=8.13 0.46 4 0.10 ± 0

] 0.08 ] ] r 3 s s y / / 10 / s m m 30 a k k [ 0.06 [

m

s s [ o o

l 20 l

µ 2 V σ σ 0.04 20 30 1 0.02 40 σµ (16059.9 stars in fit)

σlos (374.3 members, 4.7 outliers) 0.00 0 0 2 4 6 8 10 12 0 2 4 6 8 10 12 10 R [arcmin] R [arcmin]

7

6 0.12 NGC_4590_M_68 5 old D=10.13 0.81 70 ±

new D=10.24 0.94 5 dynamical distance [kpc] 0.10 ± 80 4 3

] 0.08 ] ] r s s y / / 90 / s m m a k 3 k [ 0.06 [

m

s s [ 2 o o

l l µ

V 100 σ σ 0.04 2 110 2 3 5 7 10 20 30 0.02 1 literature distance [kpc] σµ (147.0 stars in fit) 120 σlos (256.4 members, 7.6 outliers) 0.00 0 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 large uncertainties but R [arcmin] R [arcmin] general agreement with literature 2.3 PM anisotropy profiles

0.3 NGC 104 0.3 NGC 3201 0.3 NGC 6218

1 0.2 1 0.2 1 0.2

− 0.1 − 0.1 − 0.1 R R R tangential , , ,

µ 0.0 µ 0.0 µ 0.0 σ σ σ ↔ / / /

t 0.1 t 0.1 t 0.1 , , , µ 0.2 µ 0.2 µ 0.2 σ σ σ

0.3 radial 0.3 0.3

0 5 10 15 20 25 30 0 5 10 15 20 0 2 4 6 8 Radius [arcmin] Radius [arcmin] Radius [arcmin]

0.3 NGC 5139 0.3 NGC 6121 0.1 NGC 7078

1 0.2 1 0.2 1 0.0

− 0.1 − 0.1 − 0.1 R R R , , ,

µ 0.0 µ 0.0 µ 0.2 σ σ σ / / /

t 0.1 t 0.1 t 0.3 , , , µ 0.2 µ 0.2 µ 0.4 σ σ σ 0.3 0.3 0.5

0 5 10 15 20 25 30 35 0 5 10 15 20 0 2 4 6 8 Radius [arcmin] Radius [arcmin] Radius [arcmin] variety of profiles, mostly weakly radial or isotropic 2.4 Perspective effects in the radial PM component Perspective contraction/expansion due to line-of-sight motion: ◦ µR (R) = ξ R, ξexpected = −vLOS/D × (π/180 /4.74) mas/yr/degree.

0.4 20 NGC 3201 0.3 15 0.2 n d e C e

r ω u M 4 s 0.1 a 10 M 5 e count m

ξ 0.0 47 Tuc NGC 6397 M 3 NGC 6752 0.1 5 M 22 M 13 0.2 0 0.2 0.1 0.0 0.1 0.2 0.3 0.4 2 1 0 1 2 ξexpected (ξ ξ )/² meas − exp ξ (error bars take into account spatially correlated systematics) 2.5 Orbits of clusters in the Milky Way

NGC 6712 M 79 1.0 NGC 5946 Pal 14 1.0 NGC 362 M 72 NGC 4147 NGC 6287 NGC 1851

M 92 M 75 NGC 6229 NGC 7006 Pal 2 Pal 6 M 2 Pal 15 NGC 5694

Pal 4 NGC 5286 IC 1257 NGC 6544 NGC 1261 VVV CL002 NGC 6642 NGC 6638 NGC 6401 NGC 6284 NGC 2298 M 56 ESO 452 M 70 NGC 2808 NGC 6934 UKS 1 NGC 6440 NGC 4833

Djorg 1 M 4 NGC 6584 NGC 6652 NGC 5986 M 5 Eridanus Terzan 2 NGC 6528 NGC 5634 NGC 7492 NGC 6355 NGC 6293 AM 1 Terzan 10 M 9 ESO 280 0.8 M 13 NGC 2419 Ryu 059 NGC 6453 Ryu 879 Pal 13 NGC 288 Rup 106 Laevens 3 NGC 6380 M 30 NGC 6517 NGC 5466 BH 229 M 19 0.5 NGC 6558 Terzan 9 M 14 M 55 M 28 Terzan 6

Liller 1 NGC 6426 M 80 BH 140 Pyxis Terzan 5 FSR 1735 Kim 3

NGC 6535 VVV CL001 ω

C )

e

NGC 6624 FSR 1758

n

IC 4499 L NGC 5897

0.6 Terzan 1 / z NGC 6316 M 22 NGC 6522 M 107 NGC 6541 NGC 6101 L NGC 6749

M 3 Terzan 7 ( Gran 1 NGC 6388 Pal 12 Terzan 8

NGC 6366 M 54

NGC 3201M 68 n

Arp 2 o NGC 6139 0.0

NGC 6397 Whiting 1 i Terzan 4 NGC 6723 Mercer 5 NGC 6760 Pal 8 M 15 t MBH 10184NGC 6441 M 53 NGCNGC 62356356 a Pal 9 NGC 4372 n

NGC 6144 M 12 NGC 5824 i l eccentricity

0.4 M 62 c NGC 6496

FSR 1716NGC 6362 n i NGC 6325 Ton 2 Pal 7 Terzan 12 Pal 3 Djorg 2 M 69 BH 261 Pal 11 Pal 5 Pfleiderer 2 NGC 6342 NGC 6304 Pal 10 NGC 5053 NGC 6540 NGC 6752 Ko 2

Bliss 1 NGC 6539 Munoz 1 Ko 1 0.5

Terzan 3

NGC 6569 Crater 0.2 M 71 BH 176

47 Tuc E 3 NGC 6553

NGC 6256 AM 4 NGC 5927 NGC 6352 Pal 1

ESO 93-8 Segue 3 retrograde prograde 0.0 1.0 0.7 1 2 3 5 7 10 20 30 50 70 100 semimajor axis [kpc] distance errors are the major source of uncertainty in orbit parameters Summary: Gaia EDR3 ⇐⇒ globular clusters

I Statistical uncertainties are underestimated by 10 − 20% in dense regions (even for the clean subset); I Spatially correlated systematic errors on sub-degree scales: $ ' 0.01 − 0.02 mas, µ ' 0.025 mas/yr; I Parallax zero-point correction overshoots by ∼ 0.008 mas.

I Mean parallaxes, PM and orbits determined for 170 globular clusters; I PM dispersions and dynamical distances – for ∼ 100 clusters; I Rotation detected in ∼ 20 clusters; I PM anisotropy measured in ∼ 20 clusters.