Debris from dwarf satellites in the Auriga simulations 0 . 0 All - PowerPoint PPT Presentation

Debris from dwarf satellites in the Auriga simulations 0 . 0 All sources Random Sub-sample E × 10 − 5 (km 2 s − 2 ) Christine Simpson − 0 . 5 University of Chicago − 1 . 0 − 1 . 5 N s : 5.1e+05 N s : 3.0e+04 N p : 3.2e+04 N p : 3.0e+04 HITS − 2 . 0 Ignacio Gargiulo f acc : 0.39 f acc : 0.37 Facundo Gómez 0 . 0 E × 10 − 5 (km 2 s − 2 ) Rob Grand − 0 . 5 − 1 . 0 and − 1 . 5 N s : 3.9e+05 N s : 3.0e+04 The Auriga Collaboration N p : 3.1e+04 N p : 3.0e+04 ICC − 2 . 0 f acc : 0.37 f acc : 0.4 − 4 − 2 0 2 4 − 4 − 2 0 2 4 L z (Mpc km s − 1 ) L z (Mpc km s − 1 ) arXiv:1905.09842

AURIGA disks HIGH-RESOLUTION SIMULATIONS OF MILKY WAY-SIZED HALOS (Grand et al. 2017) The Set-up & Physics • Cosmological zoom simulations of 10 12 M ⊙ halos • baryon cell/particle mass ~6 x 10 3 M ⊙ for 6 halos; ~5 x 10 4 M ⊙ for 40 halos • Second-order hydrodynamics on a moving mesh (AREPO) • MHD, SF & stellar feedback, AGN feedback, UV background, atomic & metal line cooling

Satellites in Auriga M host : 1-2 x 10 12 M ⊙ (30) M host : 0.5-1 x 10 12 M ⊙ (10) 10 2 10 2 MW Au-L3 Surviving d < 300 kpc d < 300 kpc M31 Au-L6 Cumulative Number Cumulative Number L4 Au-L7 satellite MW M31 10 1 10 1 Luminosity L4 Functions 10 0 10 0 � 10 � 12 � 14 � 16 � 18 � 20 � 22 � 10 � 12 � 14 � 16 � 18 � 20 � 22 M V M V

Many satellites don’t survive but they are still present in the Galaxy New GAIA Picture Pre-Gaia Picture V. Belokurov & SDSS Ibata et al. 2019 Bullock & Johnston 2005 Belokurov et al.

We should expect debris to remain correlated in phase space longer than in position space Binding/Orbital Energy: Angular Momentum: E = v 2 /2 + ɸ L = r x v Prograde Retrograde (rotating with disk) Binding Energy . 0 Au6 . 5 . 0 . 5 . 0 z-component Angular Momentum

Accreted material in Auriga shows a diversity of phase space structure 0 . 0 N acc N acc = 1.8e+04 = 1.7e+04 Au-24 Au-21 E × 10 − 5 (km 2 s − 2 ) p p − 0 . 5 • (Currently) Highest resolution Auriga − 1 . 0 simulations: 5 x 10 3 − 1 . 5 M ⊙ per star particle f acc = 0.1 f acc = 0.07 f acc f acc ret = 0.16 ret = 0.24 − 2 . 0 • Accreted stars in 0 . 0 2.5 kpc sphere N acc N acc = 2.1e+04 = 5.1e+03 Au-23 Au-6 E × 10 − 5 (km 2 s − 2 ) p p positioned 8 kpc − 0 . 5 from center are − 1 . 0 shown − 1 . 5 f acc = 0.1 f acc = 0.03 f acc f acc ret = 0.09 ret = 0.39 − 2 . 0 − 4 − 2 0 2 4 − 4 − 2 0 2 4 L z (Mpc km s − 1 ) L z (Mpc km s − 1 )

Satellite-Host Disk connection Angle between L orb and L host-disk Red: Dark Satellites Cyan: Luminous satellites 0 . 9 satellite Grand et al. 2017 L host-disk 0 . 8 L orb 𝜄 0 . 7 0 . 6 0 . 5 pdf host 0 . 4 0 . 3 0 . 2 0 . 1 Simpson in prep 0 . 0 − 1 . 0 − 0 . 5 0 . 0 0 . 5 1 . 0 cos( θ )

Chemical and dynamical cuts (aka GAIA doesn’t have accretion flags) N p = 20224 0 . 0 Accreted f acc = 1.0 f ret , pro = 1.0, 1.0 acc E × 10 − 5 (km 2 s − 2 ) − 0 . 5 • Apply cuts in Fe, Accreted − 1 . 0 Mg, and circularity Only • Structures in this − 1 . 5 case created by f ret = 0.11 − 2 . 0 massive satellite (Mstar = 5 x 10 9 N p = 21055 [Fe / H] < 0 0 . 0 f acc = 0.38 [Mg / Fe] > − 0 . 3 Msun) disrupted 3 f ret , pro = 0.45, 0.36 ✏ < 0 . 7 acc E × 10 − 5 (km 2 s − 2 ) − 0 . 5 Chemically & Gyr ago Dynamically − 1 . 0 Selected − 1 . 5 f ret = 0.22 − 2 . 0 − 4 − 2 0 2 4 L z (Mpc km s − 1 )

Mock Observations: Aurigaia Use mock-Gaia catalogues of our • N p = 21055 0 . 0 [Fe / H] < 0 f acc = 0.38 [Mg / Fe] > − 0 . 3 f ret , pro = 0.45, 0.36 ✏ < 0 . 7 acc E × 10 − 5 (km 2 s − 2 ) simulations (Grand et al. 2018). − 0 . 5 − 1 . 0 Two methods applied with different • − 1 . 5 assumptions about phase space f ret = 0.22 − 2 . 0 smoothing (HITS,ICC) − 4 − 2 0 2 4 L z (Mpc km s − 1 ) Use a 3 component fit for the galaxy • potential with mock (use true potential for simulations) 0 . 0 All sources Random Sub-sample E × 10 − 5 (km 2 s − 2 ) − 0 . 5 10 6 − 1 . 0 10 5 HITS ICC Simulation − 1 . 5 10 4 Number N s = 5.1e+05 N s = 3.0e+04 N p = 3.2e+04 N p = 3.0e+04 − 2 . 0 10 3 HITS mock f acc = 0.39 f acc = 0.37 10 2 10 1 0 . 0 E × 10 − 5 (km 2 s − 2 ) − 0 . 5 Normalized 8 Number 6 − 1 . 0 4 2 − 1 . 5 0 N s = 3.9e+05 N s = 3.0e+04 − 2 . 0 − 1 . 5 − 1 . 0 − 0 . 5 0 . 0 N p = 3.1e+04 N p = 3.0e+04 − 2 . 0 ICC mock f acc = 0.37 f acc = 0.4 E × 10 − 5 (km 2 s − 2 ) − 4 − 2 0 2 4 − 4 − 2 0 2 4 L z (Mpc km s − 1 ) L z (Mpc km s − 1 )

Mock Observations: Aurigaia 2pt correlation functions measure the • N p = 21055 0 . 0 [Fe / H] < 0 f acc = 0.38 [Mg / Fe] > − 0 . 3 f ret , pro = 0.45, 0.36 excess of star pairs as a function of ✏ < 0 . 7 acc E × 10 − 5 (km 2 s − 2 ) − 0 . 5 their velocity difference − 1 . 0 Low velocity difference excess doesn’t • − 1 . 5 f ret = 0.22 seem to correlate with phase space − 2 . 0 − 4 − 2 0 2 4 structures L z (Mpc km s − 1 ) High velocity excess does not indicate • a counter rotating disk 0 . 0 All sources Random Sub-sample E × 10 − 5 (km 2 s − 2 ) 1 . 9 Sim, all accreted − 0 . 5 Au-23 Sim, all CHDYN 1 . 7 HITS-mock, CHDYN, unique parents (UP) − 1 . 0 1 . 5 HITS-mock, CHDYN, non-UP ξ + 1 ICC-mock, CHDYN, UP − 1 . 5 1 . 3 ICC-mock, CHDYN, non-UP N s = 5.1e+05 N s = 3.0e+04 1 . 1 N p = 3.2e+04 N p = 3.0e+04 − 2 . 0 HITS mock f acc = 0.39 f acc = 0.37 0 . 9 1 . 9 0 . 0 Au-6 Au-23 E × 10 − 5 (km 2 s − 2 ) ICC-mock Au-16 Au-24 1 . 7 volumes − 0 . 5 Au-21 Au-27 1 . 5 ξ + 1 − 1 . 0 1 . 3 − 1 . 5 1 . 1 N s = 3.9e+05 N s = 3.0e+04 N p = 3.1e+04 N p = 3.0e+04 0 . 9 − 2 . 0 ICC mock f acc = 0.37 f acc = 0.4 0 100 200 300 400 500 600 700 800 − 4 − 2 0 2 4 − 4 − 2 0 2 4 | v i − v j | (km s − 1 ) L z (Mpc km s − 1 ) L z (Mpc km s − 1 )

Satellite Quenching in Auriga Simpson et al. 2018 z=0.11 d=61 kpc distance < 300 kpc Level 4: all (356) Fraction of Quenched Satellites 1 . 0 Level 4: subset (76) Level 3: subset (83) 0 . 8 0 . 6 z=0.1 0 . 4 d=48 kpc 0 . 2 0 . 0 10 6 10 7 10 8 10 9 10 10 10 11 Final M star (M � ) Is the MW typical? The SAGA survey Number of SF satellites within 300 kpc 12 12 SF Auriga quenched Auriga Number of quenched satellites 10 10 SF SAGA quenched SAGA 8 8 within 300 kpc 6 6 4 4 Magnitude 2 2 Limit: M r < -12.3 0 0 10 10 10 11 10 10 10 11 Host Stellar Mass (M � ) Host Stellar Mass (M � )

Conclusions •Auriga hosts satellite debris that can be seen in position & phase 0 . 0 All sources Random Sub-sample space E × 10 − 5 (km 2 s − 2 ) − 0 . 5 •There is a diversity in accreted − 1 . 0 structures between halos − 1 . 5 •Mock observations are N s : 5.1e+05 N s : 3.0e+04 N p : 3.2e+04 N p : 3.0e+04 HITS − 2 . 0 f acc : 0.39 f acc : 0.37 necessary to make observational predictions, but 0 . 0 E × 10 − 5 (km 2 s − 2 ) challenges remain in this step of − 0 . 5 the process − 1 . 0 •Future work will entail − 1 . 5 N s : 3.9e+05 N s : 3.0e+04 N p : 3.1e+04 N p : 3.0e+04 ICC connecting debris structures to − 2 . 0 f acc : 0.37 f acc : 0.4 progenitor properties & orbits − 4 − 2 0 2 4 − 4 − 2 0 2 4 L z (Mpc km s − 1 ) L z (Mpc km s − 1 ) and modifying simulations to better capture dynamical mixing

A note on ‘stretching’ Child star c comes from 0 . 0 All sources Random Sub-sample E × 10 − 5 (km 2 s − 2 ) Parent particle p: − 0 . 5 r (c) = r (p) + dr − 1 . 0 v (c) = v (p) + dv − 1 . 5 N s = 5.1e+05 N s = 3.0e+04 N p = 3.2e+04 N p = 3.0e+04 − 2 . 0 HITS mock f acc = 0.39 f acc = 0.37 E kin (c) = E kin (p) + v (p) · dv + 0 . 0 E × 10 − 5 (km 2 s − 2 ) 0.5 dv 2 − 0 . 5 − 1 . 0 Even if E(p 1 ) = E(p 2 ), the energy of their − 1 . 5 N s = 3.9e+05 N s = 3.0e+04 children won’t be N p = 3.1e+04 N p = 3.0e+04 − 2 . 0 ICC mock f acc = 0.37 f acc = 0.4 E(c 1 ) ≠ E(c 2 ) − 4 − 2 0 2 4 − 4 − 2 0 2 4 L z (Mpc km s − 1 ) L z (Mpc km s − 1 )

Chemical and Dynamical Selection cuts E × 10 − 5 (km 2 s − 2 ) E × 10 − 5 (km 2 s − 2 ) E × 10 − 5 (km 2 s − 2 ) N p : 240077 N p : 20224 N p : 21055 0 . 0 0 . 0 0 . 0 All Accreted CHDYN f ret : 0.02 f ret : 0.11 f ret : 0.22 − 0 . 5 − 0 . 5 − 0 . 5 − 1 . 0 − 1 . 0 − 1 . 0 − 1 . 5 − 1 . 5 − 1 . 5 f ret , pro f ret , pro acc acc − 2 . 0 − 2 . 0 − 2 . 0 0.44, 0.08 0.45, 0.36 − 4 − 2 0 2 4 − 4 − 2 0 2 4 − 4 − 2 0 2 4 L z (Mpc km s − 1 ) L z (Mpc km s − 1 ) L z (Mpc km s − 1 ) 0 . 2 0 . 2 400 All All All 0 . 1 0 . 1 v circ (km s − 1 ) 0 . 0 0 . 0 200 [Mg/Fe] [Mg/Fe] − 0 . 1 − 0 . 1 0 − 0 . 2 − 0 . 2 − 200 − 0 . 3 − 0 . 3 − 0 . 4 − 0 . 4 − 400 − 0 . 5 − 0 . 5 − 400 − 200 0 200 400 − 3 − 2 − 1 0 1 − 1 . 0 − 0 . 5 0 . 0 0 . 5 1 . 0 v rad (km s − 1 ) [Fe/H] Circularity ✏