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 j θmemb) + (1 − η) ffield(xi j 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<R<14, 13.0<G<17.0 0<R<14, 17.0<G<18.5 0<R<14, 18.5<G<20.0 0<R<14, 6p 10-4 centre 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<R<20, 13.0<G<17.0 14<R<20, 17.0<G<18.5 14<R<20, 18.5<G<20.0 14<R<20, 6p 10-4 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<R<40, 13.0<G<17.0 20<R<40, 17.0<G<18.5 20<R<40, 18.5<G<20.0 20<R<40, 6p 10-4 4 3 2 1 0 1 2 3 4 4 3 2 1 0 1 2 3 4 4 3 2 1 0 1 2 3 4 4 3 2 1 0 1 2 3 4 ( )/² ( )/² ( )/² ( )/² i − , i i − , i i − , i i − , i 1.1 Statistical uncertainties are slightly underestimated 1.30 5p, 13.0<G<17.0 5p, 17.0<G<18.5 5p, 18.5<G<20.0 6p NGC 1.25 104 η 3201 r o 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<G<17.0 5p, 17.0<G<18.5 5p, 18.5<G<20.0 6p NGC 1.25 104 η 3201 r o 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<G<18 13<G<19 13<G<21 80 150 300 104 60 5139 6397 100 200 ] 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 $ after applying the parallax zero-pointmean correction parallaxes from of Lindegren+ cluster members vs. literature distances $; ∆ i sys $ − 1 ' ' = D 0 0 : : i 008 01 ∼ N mas mas . (∆ ; $; $; 2 i + 2 $; 2 sys NGC 7492 (compilation of literature data by H.Baumgardt) NGC 5824 ), 1.5 Pal 11 NGC 6356 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 NGC 6355 NGC 6287 1.2 M 62 e NGC 6934 c 2012.01742 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] 2.1 Internal kinematics: rotation, dispersion Good agreement with HST µ σ rot µ σ µ [Watkins+ 2015, Cohen+ 2021] 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 / 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 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] and 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 σ 0.8 20 0.15 LOS 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 from literature [ [ [ 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] 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.