Using Gaia for Studying Milky Way Star Clusters

Using Gaia for studying Milky Way star clusters

Eugene Vasiliev

Institute of Astronomy, Cambridge

IAU 351 / MODEST-19, Bologna, 27 May 2019

Internal kinematics and galactic orbits 1811.05345 1807.09775 Overview of Gaia mission and Data Release 2 Scanning the entire sky every couple of weeks I G I DR2 based on 22 months of observations I Astrometry for sources down to 21 mag (1.3 × 109) BP RP RVS I Broad-band blue/red photometry (1.4 × 109) I Radial velocity down to ∼ 13 mag (∼ 7 × 106 stars) ! No special treatment of binary stars

] 10

! Poor completeness in crowded ﬁelds 1 ¡

r proper motion uncertainty [mas/yr] y 5 s a m [ ) x

RV measurements only for stars a 2 m ; m p

¾ 1 with Teﬀ ∈ [3500 ÷ 6900] K ( : m : 0:5 p n i e s

p 0:2 i l l e r

o 0:1 r r e f

o 0:05 s i x

a systematic error r o

j 0:02 a m ¡ i 0:01 1 mas/yr = 4.7 km/s × (D/1 Kpc) m e S 0:005 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 G magnitude [Katz+ 2018] [Lindegren+ 2018] Determination of cluster membership Determination of cluster membership Probabilistic membership determination

A hard cutoﬀ in PM space is not always possible and is conceptually unsatisfactory.

A more mathematically well-grounded alternative: gaussian mixture modelling.

f (µi ) = qcl N (µi | µcl, Σcl;i ) + (1 − qcl) N (µi | µfg, Σfg;i )

exp − 1 (µ − µ)T Σ−1 (µ − µ) N (µ | µ, Σ) ≡ 2 √ , 2π det Σ where the mean PMs µ and dispersions Σ of the cluster and foreground distributions, and the fraction of cluster members qcl, are all inferred by maximizing the likelihood of the observed stellar PMs. Probabilistic membership determination

Take into account the measurement errors µα , µδ , ρµαµδ for each star i:

2 2 ! σcl(ri ) + µα ρµαµδ µα µδ Σcl;i = ρ σ2 (r ) + 2 µαµδ µα µδ cl i µδ

2 ! Sαα + µα Sαδ + ρµαµδ µα µδ Σfg;i = S + ρ S + 2 αδ µαµδ µα µδ δδ µδ

And allow for a spatially-dependent density of cluster members: qcl(ri ). N Pstars Maximize ln L ≡ ln f (µi ) by adjusting free parameters: i=1 µcl, µfg, Sαα, Sδδ, Sαδ, radius and normalization of qcl(r), normalization of σcl(r). Posterior membership probability for each star:

qcl(ri ) N (µi | µcl, Σcl;i ) pcl;i = qcl(ri ) N (µi | µcl, Σcl;i ) + [1 − qcl(ri )] N (µi | µfg, Σfg;i ) Caveat: spatially correlated systematic errors in astrometry ] 2 ) r

y Covariance function 1

/ 0.004

Covariance function V (θij ) = hµi µj i, averaged over s a Covariance function 2 m

pairs of sources separated by angular distance θ: ( [

Data for quasar pairs ) 0.003 θ (

quasars at large scales, LMC stars at small scales. V Data for pairs of LMC stars

n o i t 0.002 ◦ c n

V (θ) = 0.0008 exp(−θ/20 ) u f

e c 0.001 " ◦ n a

0.0036 exp(−θ/0.25 ) (cov.fnc.1) i r

+ a ◦ v o

0.004 sinc(θ/0.5 + 0.25) (cov.fnc.2) c 0.000

M P 0 1 2 3 4 5 6 angular distance θ [deg]

0.07 4 0.10

] µ µ µ µ r cov.fnc.1, unweighted α α δ δ y

/ − − 0.08

s 0.06 cov.fnc.1, error-weighted 3 a ® ® 0.06 m cov.fnc.2, unweighted [

µ 0.05 cov.fnc.2, error-weighted 0.04 f o 1 r 0.02 o 0.04 r r

e 0 0.00

c i 0.03 t Y [deg] a 1 0.02 m

e 0.04 t 0.02

s 2 y

s 0.06

S 0.01 3 M 0.08 R 0.00 4 0.10 10-2 10-1 100 101 102 4 3 2 1 0 1 2 3 44 3 2 1 0 1 2 3 4 angular size of the cluster [deg] X [deg] X [deg] How to properly account for correlated systematic errors N Likelihood function for the entire dataset (µ ≡ {µi }i=1):

L = N (µ | 1 µ, Σ)

 2  V (0) + 1 V (θ12) V (θ13) ··· V (θ1N )  V (θ ) V (0) + 2 V (θ ) ··· V (θ )  Σ =  21 2 23 2N   ......   . . . . .  2 V (θN1) V (θN2) V (θN3) ··· V (0) + N

(1..N are statistical errors of each datapoint). This is easily generalized to 2d case with 2 × 2 covariance matrices of statistical errors, and allowing for spatially-dependent internal dispersion and mean value of µ. The downside is that one needs to invert the N × N covariance matrix Σ for the entire dataset (for the optimal error-weighted estimate). q 1 PN PN Alternatively, an unweighted estimate of the uncertainty on µ is N i=1 j=1 Σij . Spatial correlation should not be ignored!

Doing so underestimates the error bars on ﬁt parameters, even when systematic errors are much smaller than statistical errors.

ignoring correlations taking correlations into account

0. 155 0. 005 2. 707 0. 004 0. 168 0. 044 2. 681 0. 043 − ± − ± − ± − ± µα 0. 123 µδ 2. 628 µα 0. 123 µδ 2. 628 0.20 − − 0.20 − −

0.15 0.15 0.2 0.1 0.0 2.7 2.6 2.5 0.2 0.1 0.0 2.7 2.6 2.5 ] ] r r y y / 0.10 / 0.10 s s a a m m [ [

µ µ σ σ

, 0.05 , 0.05 µ µ

0.00 0.00

0.05 0.05

0 5 10 15 20 25 0 5 10 15 20 25 R [arcmin] R [arcmin] Internal kinematics of globular clusters

Clear signature of rotation in ∼ 10 clusters: see also Bianchini+ 2018, Sollima+ 2019, Jindal+ 2019, all based on Gaia data

0.25 0.6 NGC 6656 (M 22) NGC 5904 (M 5) 8 N=4171, D=3.2 kpc N=4476, D=7.6 kpc 8 0.20 0.5 ] ]

r r 6 ] ] y y

/ / 0.15 s s / / s 0.4 s

a 6 a m m k k m m 4 [ [ [ [

0.10 σ σ µ µ

0.3 σ σ , ,

t t , , v v t 4 t , ,

µ µ 2 r r

0.05 v v , ,

r 0.2 r µ µ 2 0.00 0 0.1

0.05 0.0 0 2 0 5 10 15 0 5 10 15 R [arcmin] R [arcmin] Internal kinematics of globular clusters

Good match between line-of-sight velocity dispersion and PM dispersion: see also Baumgardt+ 2018, Jindal+ 2019 (Gaia PM) and HST measurements in central parts [Bellini+ 2014, Watkins+ 2015]

6 0.5 NGC 6397 0.25 NGC 7089 (M 2) N=10000, D=2.4 kpc 5 N=1296, D=10.5 kpc 0.4 0.20 10 ] ] r 4 r ] ] y y / / s s

/ 0.15 / s 0.3 s a a m m k k m 3 m [ [ [ [

0.10 5 σ σ µ µ

σ σ 0.2 , ,

t t , , v v t 2 t , ,

µ µ 0.05 r r

v v , , r r

µ 0.1 µ 1 0.00 0

0.0 0 0.05

0 5 10 15 20 0 2 4 6 8 10 12 R [arcmin] R [arcmin] Internal kinematics of globular clusters

Mismatch between σlos and PM dispersion in central parts: likely due to crowding issues and aggressive sample cleanup

0.6 NGC 104 (47 Tuc) NGC 6752 0.4 8 N=10000, D=4.4 kpc N=10000, D=4.2 kpc 10 ] ]

r 0.4 r 0.3 6 ] ] y y / / s s / / s s a a m m k k m 5 m [ [ [ [ 0.2 4 0.2 σ σ µ µ

σ σ , ,

t t , , v v t t , , µ µ r r

v v , , 0.1 2 r 0.0 0 r µ µ

0.0 0 0.2 5

0 5 10 15 20 25 30 0 5 10 15 20 R [arcmin] R [arcmin] Internal kinematics of globular clusters

Overall scale mismatch between σlos and σµ: a prime method for measuring the distance from kinematic analysis

0.6 4 NGC 6121 (M 4) 0.20 NGC 6838 (M 71) N=7538, D=2.0 kpc 5 N=1983, D=4.0 kpc 0.5 3 0.15

] 4 ] r r ] ] y 0.4 y / / s s / / s s

a a 2 3 m 0.10 m k k m m [ [

[ 0.3 [

σ σ µ µ

σ σ , ,

t t , , v v t 2 t 0.05 1 0.2 , , µ µ r r

v v , , r r µ 0.1 1 µ 0.00 0

0.0 0 0.05 1 0 5 10 15 20 0 1 2 3 4 5 6 7 8 R [arcmin] R [arcmin] Kinematics of the entire Milky Way globular cluster system

see also Gaia Collaboration (Helmi+) 2018, Baumgardt+ 2018, de Boer+ 2019

∼ 150 globular clusters in the Milky Way Previous measurements of mean PM of globular clusters 10 10 10 10 HST Dinescu Chemel Kharchenko

5 5 5 5 ] r y /

s 0 0 0 0 a m [ r e t

i 5 5 5 5 l , α µ 10 10 10 10

15 15 15 15 15 10 5 0 5 10 15 10 5 0 5 10 15 10 5 0 5 10 15 10 5 0 5 10 µα, this [mas/yr] µα, this [mas/yr] µα, this [mas/yr] µα, this [mas/yr] 5 5 5 5

0 0 0 0 ] r y /

s 5 5 5 5 a m [ r e t

i 10 10 10 10 l , δ µ 15 15 15 15

20 20 20 20 20 15 10 5 0 5 20 15 10 5 0 5 20 15 10 5 0 5 20 15 10 5 0 5 µδ, this [mas/yr] µδ, this [mas/yr] µδ, this [mas/yr] µδ, this [mas/yr] 1.0 6 6 15 ] r 4 4 10 y /

s 0.5 a NGC 6838 M 71 2 2 5 m [ s i

h Terzan 5

Terzan 5 11 t

, 0.0 0 0 0 δ Terzan 8 µ NGC 6101 − Pyxis 2 2 5 r NGC 5466 e t

i 0.5 l ,

δ 4 4 10 µ

1.0 6 6 15 1.0 0.5 0.0 0.5 1.0 6 4 2 0 2 4 6 6 4 2 0 2 4 6 15 10 5 0 5 10 15 µ µ [mas/yr] µ µ [mas/yr] µ µ [mas/yr] µ µ [mas/yr] α, liter − α, this α, liter − α, this α, liter − α, this α, liter − α, this Distribution of globular clusters in position/velocity space

[Fe/H]

2 1 0 200

Crater Crater Crater

AM 1 AM 1 AM 1

Pal 4 Pal 4 Pal 4

100 Pal 3 Eridanus Eridanus Pal 3 Eridanus Pal 3 NGC 2419 NGC 2419 NGC 2419

Pal 14 Pal 14 Pal 14

Pyxis Pal 15 Pyxis Pyxis NGC 7006Pal 15 NGC 7006 NGC 7006Pal 15 Pal 2 Pal 2 Whiting 1 Pal 2 Whiting 1 Whiting 1

NGC 5694 NGC 6229 NGCNGC 6229 5694 NGC 5824 NGC 5694 Pal 13 Pal 13 Pal 13 NGC 6229 NGC 7492 NGC 7492 NGC 5824 NGC 5824 NGC 5634 NGC 7492 NGC 4147 NGCNGC 4147 5634 NGC 4147 Arp 2 Arp 2 Arp 2 M 79 NGC 1261M 79 NGC 5634 20 Rup 106 NGC 1261M 79 Terzan 8 NGCM 5053 53 Pal 5 M 53 Pal 5 M 53 M 54 NGC 1851 TerzanM 854 Pal 5 NGC 5053 NGC 1261 M 54 Rup 106 Terzan 8 IC 1257NGC 1851 NGC 5053 Pal 1 Pal 1 NGC 5466 IC 4499 Pal 1 NGC 1851 NGCIC 12572298 Rup 106 Pal 12 IC 1257 IC 4499 NGC 5466 NGC 2298 NGC 5466 Pal 12 NGC 2298 IC 4499 Pal 12 Terzan 7 NGC 6426 Terzan 7 BH 176 M 75 M 75 M 75 M 72 Terzan 7 NGC 6426 ESO280 NGC 6426

NGC 6101 ESO280 BH 176 ESO280 M 72 NGC 288 M 72 M 3 NGC 288 NGC 6934 NGCM 288 3 NGC 2808 NGC 6934 BH 176 M 3 NGC 6934 NGC 2808 M 15 NGC 6101 NGC 2808 M 2 M 2 M 15 NGC 6101 M 68 M 68 M 2 M 68 M 92 M 15 M 92 NGC 5286 10 NGC 362 NGCM 5286 92 M 56 E 3 NGC 362 M 56 NGC 5286 M 56 E 3 NGC 3201 NGC 362 E 3 NGC 3201 NGC 3201 M 13 NGC 6284 M 13 M 13 NGC 6356 47 TucPal 11 Pal 11NGC 5897 Pal 11 47 Tuc NGC 483347 Tuc M 30 M 30 M 30 NGC 4372 NGC 4372 M 71 NGC 4833 M 71 NGC 4372 NGC 4833 NGC 5897 r [kpc] NGC 5897 M 71 ω Cen ω Cen NGC 6356NGC 6284 Cen NGC 6284 NGC 6356 Pal 10 Pal 10 M 4 Pal 10 NGC 6584 ω NGC 6584 NGC 6397 NGC 6397 M 5 M 5 M 4 NGCM 6584 5 M 4 NGC 6752 NGC 6366NGC 6544 NGC 6397 NGC 5946 NGCPal 8 6362 M 22 NGC 5946 NGC 5946 M 22 Pal 8 NGC 6760 Pal 8 M 12 M 10 NGC 6362 NGC 6362 NGC 6749M 12 NGC 6752 NGC 6544 NGC 6760NGC 6752M 22 5 NGC 6544 NGC 6760 FSR 1735 NGC 6749 NGC 5927 NGC 6366 NGC 5927 NGC 6235 NGC 6366 M 10 M 1210 NGC 5986 FSR 1735 NGC 6749 NGC 5986 NGC 5986 NGC 5927 NGC 6517BH 184 BH 184 BH 184 M 55 FSR 1735 Pal 7 NGC 6535 Terzan 12 NGC 6352 M 80 M 14 NGC 6535 M 55 M 14 M 14 NGC 6535 M 55 Pal 7 NGC 6380 NGC 6496 NGC 6380 NGC 6712 NGC 6496 NGC 6235 NGC 6496 Pal 7 NGC 6712 M 107NGC 6235 NGC 6517 M 80 M 80NGC 6517 NGC 6388

NGC 6540 NGC 6712 NGC 6569 NGC 6388 NGC 6540 NGC 6256 NGC 6441

NGC 6441 NGC NGC6352 6453 NGC 6441 M 107 NGC 6388 NGC 6139 M 107 NGC 6139 NGC 6453 NGC 6453 NGC 6139 Terzan 12 M 28 NGC 6539 Terzan 12 NGC 6539 NGC 6352 NGC 6539 NGC 6652 NGC 6144

NGC 6304 NGC 6316 NGC 6380 M 28 NGC 6401 NGC 6144 M 28 NGC 6144NGC 6723 NGC 6553 Pal 9 NGC 6540 NGC 6569 NGC 6569 NGC 6553 NGC 6256 NGC 6723 NGC 6256 Pal 6 NGC 6723 Terzan 3 Terzan 3 Terzan 10 Terzan 3 Terzan 10 Pal 9 NGC 6652 Terzan 10 Pal 9 NGC 6638 NGC 6287 NGC 6638 NGC 6541 Pal 6 NGC 6541 NGC 6401 Pal 6 NGC 6652 NGC 6401 ESO452 NGC 6316 NGC 6316 NGC 6304 ESO452NGC 6304 NGC 6541 NGC 6293 M 70 NGC 6293 M 70

NGC 6553 M 70 ESO452M 62 2 NGC 6287 ESO456 BH 261 BH 261 NGC 6287 BH 261

NGC 6293 M 62 NGC 6638 M 62 ESO456 ESO456 M 9 Terzan 1 NGC 6642 NGCTerzan 1 6642 M 9 M 69 M 9 NGC 6642 NGC 6342 M 69 Terzan 5 M 19 NGC 6342Terzan 5 M 19 M 19 M 69 NGC 6355 NGC 6355 NGC 6342 NGC 6440 Pismis 26 Pismis 26 Terzan 9 Pismis 26 Terzan 9 NGC 6440 NGC 6624 NGC 6440 Terzan 1

Terzan 4 Terzan 6 Terzan 6 Terzan 6 NGC 6325 Terzan 5 NGC 6624 NGC 6558 NGC 6355 NGC 6624 NGC 6325 NGC 6325

Terzan 9 NGC 6558

Terzan 4 Terzan 4 1 NGC 6558

Terzan 2 Terzan 2 NGC 6522 Terzan 2 Liller 1 Liller 1 Liller 1 NGC 6522 NGC 6528 NGC 6528 NGC 6528 NGC 6522

BH 229 0.5 BH 229 BH 229 0 50 100 150 200 250 300 0 50 100 150 200 250 300 300 200 100 0 100 200 300 v [km/s] v vφ | r| | θ| Velocity dispersion and rotation proﬁles

Main kinematical features of the

entire population of globular clusters: 150 σr I Signiﬁcant overall rotation,

especially within the central 10 kpc 100 σ ] θ (more prominent for metal-rich clusters). s / m k

[ σφ

I Nearly isotropic dispersion at r < 10 kpc, σ

, 50 more radially anisotropic in outer parts; v

a population of ∼ 10 clusters on vφ 0 eccentric orbits [Myeong+ 2018]. vθ Correlated orbits (e.g., Sgr stream: I vr 50 M 54, Terzan 7, Terzan 8, Arp 2, Pal 12, Whiting 1). 1 10 100 r [kpc] Distribution of globular clusters in action space

polar (Jφ =0)

NGC 6723 1 5 M 69 2 10 20 50 100

BH 229 NGC 6624 Rcirc [Kpc]

) ci 0 NGC 6342 rc inner Galaxy = M 80 ul J r NGC 6144 NGC 6522 a ( r outer Galaxy ESO452 ar (J ul r = rc NGC 6325 NGC 6539 0 ci ) NGC 6652 M 107

NGC 6362 Terzan 3

FSR 1735 NGC 6453 Pal 9 NGC 6139 M 12 M 19 NGC 6355 M 62 prograde NGC 6528 NGC 6569

NGC 6541 NGC 6401 Terzan 10 BH 261 M 55 NGC 6752

NGC 6352 M 70 NGC 6558 M NGC10 6397 NGC 6293 Ton 2 Terzan 4 NGC 6304 NGC 5927 NGC 6440 M 14 NGC 5053

NGC 6388 Terzan 12 NGC 6638 Pal 8 NGC 6540 NGC 6553

NGC 6287 retrograde NGC 6366 Pal 7 BH 184 NGC 6535 NGC 6316 Terzan 7 M 28 Terzan 8 NGC 5986 Pal 5 ω NGC 6760 C NGC 6642 e n NGC 6441 Arp 2 M 53 Terzan 2 ESO456 M 54 Pal 6 NGC 6749 NGC 6256 NGC 6712 NGC 5946 i NGC 6517 Terzan 5 n ) Whiting 1 - Terzan 9 p Terzan 6 0 la = n J z e Terzan 1 ( (J NGC 6380 ne NGC 5824 z = Djorg 1 la 0 NGC 6544 -p Pal 12 ) in NGC 5897 NGC 6235 NGC 4833 M 3

M 30 Pyxis

IC 4499 47 Tuc

NGC 6752E 3 M 4 NGC 6397 0 NGC 6356 Pal 11

NGC 288 M 13 Pal 1

NGC 7492 M 68 FSR 1716 NGC 5927 radial (J =0) M 71 φ M 15 BH 176 NGC 5466

NGC 6287 Pal 7 J → Pal 10 z NGC 6101 NGC 6496 NGC 4372 NGC 6284 polar NGC 3201 M 22

FSR 1758 NGC 5634 ω M 5

C M 9 e Pal 13 prograde n ESO280 M 92 NGC 6426

NGC 2298

Rup 106 Jφ NGC 362 180◦ ← inclination → 0◦ NGC 6584 M 75

NGCM 126156 IC 1257 NGC 5286 M 2 Djorg 1 retrograde NGC 4147

NGC 7006 NGC 4833 NGC 5694 NGC 6229

eccentricity M 72 NGC 6934 NGC 1851 NGC 2808 M 79 radialJ

r ← Pal 2 1 Distribution of globular clusters in action space

polar (Jφ =0)

NGC 6723 1 5 M 69 2 10 20 50 100

BH 229 NGC 6624 Rcirc [Kpc]

) ci 0 NGC 6342 rc inner Galaxy = M 80 ul J r NGC 6144 NGC 6522 a ( r outer Galaxy ESO452 ar (J ul r = rc NGC 6325 NGC 6539 0 ci ) NGC 6652 M 107

NGC 6362 Terzan 3

FSR 1735 NGC 6453 Pal 9 NGC 6139 Sagittarius M 12 M 19 NGC 6355 M 62 prograde NGC 6528 NGC 6569

NGC 6541 NGC 6401 Terzan 10 BH 261 M 55 NGC 6752 [Law&Majewski 2010, . . . ]

NGC 6352 M 70 NGC 6558 M NGC10 6397 NGC 6293 Ton 2 Terzan 4 NGC 6304 NGC 5927 NGC 6440 M 14 NGC 5053

NGC 6388 Terzan 12 NGC 6638 Pal 8 NGC 6540 NGC 6553

M 30 Pyxis

IC 4499 47 Tuc

NGC 6752E 3 M 4 NGC 6397 NGC 6356 Pal 11

NGC 288 M 13 Pal 1

NGC 7492 M 68 FSR 1716 NGC 5927 radial (J =0) M 71 φ M 15 BH 176 NGC 5466

NGC 6287 J Pal 7 Pal 10 z NGC 6101 NGC 6496 NGC 4372 NGC 6284 polar NGC 3201 M 22

FSR 1758 NGC 5634 ω M 5

C M 9 e Pal 13 prograde n ESO280 M 92 NGC 6426

NGC 2298

Rup 106 Jφ NGC 362 NGC 6584 radially M 75

NGCM 126156 IC 1257 NGC 5286 M 2 Djorg 1 retrograde NGC 4147 anisotropic

NGC 7006 NGC 4833 NGC 5694 Sequoia M 72NGC 6229 population NGC 6934 NGC 1851 NGC 2808 M 79 radial [Myeong+ 2019] [Myeong+ 2018, Jr Pal 2 Helmi+ 2018] Distribution of globular clusters in action space

Jackson Pollock Kliment Redko Dynamical modelling of the entire globular cluster population

Assume an equilibrium distribution function (in action space):

ηΓ/η η−B/η M J0 g(J) κJφ f (J) = 3 1 + 1 + 1 + tanh , (2π J0) h(J) J0 Jr + Jz + |Jφ|

g(J) ≡ gr Jr + gz Jz + (3 − gr − gz ) |Jφ|, h(J) ≡ hr Jr + hz Jz + (3 − hr − hz )|Jφ|,

and a potential – bulge, disk and a ﬂexible halo proﬁle:

r −γ r α(γ−β)/α ρ(r) = ρh 1 + . rh rh Maximize the likelihood of drawing the observed positions and velocities of clusters (taking into account their uncertainties) by varying the parameters of potential and DF. Results: constraints on the Milky Way potential

circular velocity curve Results are broadly consistent with 300 McMillan (2017) other studies based on globular clusters Bovy (2015) 250 total [Binney&Wong 2017, Sohn+ 2018, Watkins+ disc halo 200

2019, Posti&Helmi 2019, Eadie&Juric 2019]; ] s / m

k 150 the potential from McMillan(2017) is [ c r i c v acceptable, the one from Bovy(2015) 100 has too low rotation curve. 50 Clusters should be combined with 0 other dynamical tracers (dSph, 1 10 100 halo stars) for a more robust R [kpc] inference on the potential. Summary I Gaia revolutionized the study of Milky Way in general, and its star clusters in particular

I Internal kinematics (velocity dispersion, anisotropy, rotation) available for a few dozen globular clusters within 10–20 kpc

I Full 6d phase-space information for almost all globular clusters: orbital properties, groups, constraints on the Milky Way potential

credit: Amanda Smith, IoA