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

SLIDE 1

Debris from dwarf satellites in the Auriga simulations

Christine Simpson University of Chicago

Ignacio Gargiulo Facundo Gómez Rob Grand and The Auriga Collaboration

−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) All sources HITS

Ns: 5.1e+05 Np: 3.2e+04 facc : 0.39

Random Sub-sample

Ns: 3.0e+04 Np: 3.0e+04 facc : 0.37

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) ICC

Ns: 3.9e+05 Np: 3.1e+04 facc : 0.37

−4 −2 2 4 Lz (Mpc km s−1)

Ns: 3.0e+04 Np: 3.0e+04 facc : 0.4

arXiv:1905.09842

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AURIGA disks

HIGH-RESOLUTION SIMULATIONS OF MILKY WAY-SIZED HALOS (Grand et al. 2017) The Set-up & Physics

Cosmological zoom simulations of 1012 M⊙ halos
baryon cell/particle mass ~6 x 103 M⊙ for 6 halos; ~5 x 104 M⊙ for 40 halos
Second-order hydrodynamics on a moving mesh (AREPO)
MHD, SF & stellar feedback, AGN feedback, UV background, atomic & metal line cooling

SLIDE 3

22 20 18 16 14 12 10 MV 100 101 102 Cumulative Number

d < 300 kpc MW M31 L4

Satellites in Auriga

22 20 18 16 14 12 10 MV 100 101 102 Cumulative Number

d < 300 kpc Au-L3 Au-L6 Au-L7 MW M31 L4

Surviving satellite Luminosity Functions

Mhost: 1-2 x 1012 M⊙ (30) Mhost: 0.5-1 x 1012 M⊙ (10)

SLIDE 4

Many satellites don’t survive but they are still present in the Galaxy

V. Belokurov & SDSS

Bullock & Johnston 2005

Pre-Gaia Picture New GAIA Picture

Belokurov et al. Ibata et al. 2019

SLIDE 5

We should expect debris to remain correlated in phase space longer than in position space

.0 .5 .0 .5 .0 Au6

Binding/Orbital Energy: E = v2/2 + ɸ Angular Momentum: L = r x v

Binding Energy z-component Angular Momentum

Prograde (rotating with disk) Retrograde

SLIDE 6

Accreted material in Auriga shows a diversity of phase space structure

−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

Au-24

facc = 0.1 f acc

ret = 0.16

N acc

p

= 1.8e+04

Au-21

facc = 0.07 f acc

ret = 0.24

N acc

p

= 1.7e+04

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

Au-23

facc = 0.1 f acc

ret = 0.09

N acc

p

= 2.1e+04

−4 −2 2 4 Lz (Mpc km s−1)

Au-6

facc = 0.03 f acc

ret = 0.39

N acc

p

= 5.1e+03

(Currently) Highest

resolution Auriga simulations: 5 x 103 M⊙ per star particle

Accreted stars in

2.5 kpc sphere positioned 8 kpc from center are shown

SLIDE 7

−1.0 −0.5 0.0 0.5 1.0 cos(θ) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 pdf

Angle between Lorb and Lhost-disk Red: Dark Satellites Cyan: Luminous satellites

Satellite-Host Disk connection

Lhost-disk host satellite Lorb 𝜄 Grand et al. 2017 Simpson in prep

SLIDE 8

−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) Accreted Np = 20224 facc = 1.0 fret,pro

acc

= 1.0, 1.0 fret = 0.11 −4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) [Fe/H] < 0 [Mg/Fe] > −0.3 ✏ < 0.7 Np = 21055 facc = 0.38 fret,pro

acc

= 0.45, 0.36 fret = 0.22

Chemical and dynamical cuts (aka GAIA doesn’t have accretion flags)

Accreted Only Chemically & Dynamically Selected

Apply cuts in Fe,

Mg, and circularity

Structures in this

case created by massive satellite (Mstar = 5 x 109 Msun) disrupted 3 Gyr ago

SLIDE 9

−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

All sources HITS mock

Ns = 5.1e+05 Np = 3.2e+04 facc = 0.39

Random Sub-sample

Ns = 3.0e+04 Np = 3.0e+04 facc = 0.37

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

ICC mock

Ns = 3.9e+05 Np = 3.1e+04 facc = 0.37

−4 −2 2 4 Lz (Mpc km s−1)

Ns = 3.0e+04 Np = 3.0e+04 facc = 0.4

Mock Observations: Aurigaia

Use mock-Gaia catalogues of our

simulations (Grand et al. 2018).

Two methods applied with different

assumptions about phase space smoothing (HITS,ICC)

Use a 3 component fit for the galaxy

potential with mock (use true potential for simulations)

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) [Fe/H] < 0 [Mg/Fe] > −0.3 ✏ < 0.7 Np = 21055 facc = 0.38 fret,pro

acc

= 0.45, 0.36 fret = 0.22

101 102 103 104 105 106 Number HITS ICC Simulation −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) 2 4 6 8 Normalized Number

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−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

All sources HITS mock

Ns = 5.1e+05 Np = 3.2e+04 facc = 0.39

Random Sub-sample

Ns = 3.0e+04 Np = 3.0e+04 facc = 0.37

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

ICC mock

Ns = 3.9e+05 Np = 3.1e+04 facc = 0.37

−4 −2 2 4 Lz (Mpc km s−1)

Ns = 3.0e+04 Np = 3.0e+04 facc = 0.4

Mock Observations: Aurigaia

2pt correlation functions measure the

excess of star pairs as a function of their velocity difference

Low velocity difference excess doesn’t

seem to correlate with phase space structures

High velocity excess does not indicate

a counter rotating disk

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) [Fe/H] < 0 [Mg/Fe] > −0.3 ✏ < 0.7 Np = 21055 facc = 0.38 fret,pro

acc

= 0.45, 0.36 fret = 0.22

0.9 1.1 1.3 1.5 1.7 1.9 ξ + 1 Au-23

Sim, all accreted Sim, all CHDYN HITS-mock, CHDYN, unique parents (UP) HITS-mock, CHDYN, non-UP ICC-mock, CHDYN, UP ICC-mock, CHDYN, non-UP

100 200 300 400 500 600 700 800 |vi − vj| (km s−1) 0.9 1.1 1.3 1.5 1.7 1.9 ξ + 1 ICC-mock volumes

Au-6 Au-16 Au-21 Au-23 Au-24 Au-27

SLIDE 11

z=0.1 d=48 kpc z=0.11 d=61 kpc

Satellite Quenching in Auriga

1010 1011 Host Stellar Mass (M) 2 4 6 8 10 12 Number of quenched satellites within 300 kpc quenched Auriga quenched SAGA 1010 1011 Host Stellar Mass (M) 2 4 6 8 10 12 Number of SF satellites within 300 kpc SF Auriga SF SAGA

Magnitude Limit: Mr < -12.3

106 107 108 109 1010 1011 Final Mstar (M) 0.0 0.2 0.4 0.6 0.8 1.0 Fraction of Quenched Satellites

distance < 300 kpc Level 4: all (356) Level 4: subset (76) Level 3: subset (83)

Simpson et al. 2018

Is the MW typical? The SAGA survey

SLIDE 12

Conclusions

Auriga hosts satellite debris that

can be seen in position & phase space

There is a diversity in accreted

structures between halos

Mock observations are

necessary to make

bservational predictions, but

challenges remain in this step of the process

Future work will entail

connecting debris structures to progenitor properties & orbits and modifying simulations to better capture dynamical mixing

−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) All sources HITS

Ns: 5.1e+05 Np: 3.2e+04 facc : 0.39

Random Sub-sample

Ns: 3.0e+04 Np: 3.0e+04 facc : 0.37

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) ICC

Ns: 3.9e+05 Np: 3.1e+04 facc : 0.37

−4 −2 2 4 Lz (Mpc km s−1)

Ns: 3.0e+04 Np: 3.0e+04 facc : 0.4

SLIDE 13

−2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

All sources HITS mock

Ns = 5.1e+05 Np = 3.2e+04 facc = 0.39

Random Sub-sample

Ns = 3.0e+04 Np = 3.0e+04 facc = 0.37

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2)

ICC mock

Ns = 3.9e+05 Np = 3.1e+04 facc = 0.37

−4 −2 2 4 Lz (Mpc km s−1)

Ns = 3.0e+04 Np = 3.0e+04 facc = 0.4

A note on ‘stretching’

Child star c comes from Parent particle p: r(c) = r(p) + dr v(c) = v(p) + dv Ekin(c) = Ekin(p) + v(p)·dv + 0.5 dv2 Even if E(p1) = E(p2), the energy of their children won’t be E(c1) ≠ E(c2)

SLIDE 14

Chemical and Dynamical Selection cuts

−4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) All Np: 240077 fret: 0.02 fret,pro

acc

0.44, 0.08 −400 −200 200 400 vrad (km s−1) −400 −200 200 400 vcirc (km s−1) All −3 −2 −1 1 [Fe/H] −0.5 −0.4 −0.3 −0.2 −0.1 0.0 0.1 0.2 [Mg/Fe] All −1.0 −0.5 0.0 0.5 1.0 Circularity ✏ −0.5 −0.4 −0.3 −0.2 −0.1 0.0 0.1 0.2 [Mg/Fe] All −4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) Accreted Np: 20224 fret: 0.11 −4 −2 2 4 Lz (Mpc km s−1) −2.0 −1.5 −1.0 −0.5 0.0 E × 10−5 (km2 s−2) CHDYN Np: 21055 fret: 0.22 fret,pro

acc

0.45, 0.36

SLIDE 15