Reionization and the radial distribution of satellites

Transcription

1 Reionization and the radial distribution of satellites Andrew Graus (UC Irvine) Collaborators: James Bullock (UC Irvine) Tyler Kelley Oliver Elbert Claire Qi Michael Boylan-Kolchin (UT Austin) Alex Fitts

2 Introduction Subhalo destruction of satellites around the Milky Way - Simulating disk disruption in cosmological simulations Comparison to the distribution of galaxies The dark fraction of galaxies Fitting galaxies into halos (and failing)!2

3 Subhalo Destruction Recent state-of-the-art hydrodynamics simulations of the Milky Way have shown a decrease in the number of satellites around galaxies like the Milky Way Relative to dark matter only simulations (Brooks & Zolotov 2014, Zhu , Garrison-Kimmel ) Garrison-Kimmel !3

4 Subhalo Destruction Garrison-Kimmel !4

5 Subhalo Destruction New suite of Milky Way-like simulations (Kelley + In prep.) - 12 cosmological zoom in simulations of Milky Way like galaxies with an analytic disk (Resolve subhalos down to Vmax = 4.5 km s -1 )!5

6 Subhalo Destruction New suite of Milky Way-like simulations (Kelley + In prep.) - 12 cosmological zoom in simulations of Milky Way like galaxies with an analytic disk (Resolve subhalos down to Vmax = 4.5 km s -1 ) - Disk potential modeled similar to that in Garrison-Kimmel but with a more realistic galaxy potential!6

7 Subhalo Destruction New suite of Milky Way-like simulations (Kelley + In prep.) - 12 cosmological zoom in simulations of Milky Way like galaxies with an analytic disk (Resolve subhalos down to Vmax = 4.5 km s -1 ) - Disk potential modeled similar to that in Garrison-Kimmel but with a more realistic galaxy potential - Three component Miyamoto-Nagai potential (Smith ) with stellar / gas masses and scales matched to observations!7

8 Subhalo Destruction Kelley + In prep!8

9 Subhalo Destruction Kelley + In prep!9

10 Subhalo Destruction Factor of 2 at large radii Kelley + In prep!10

11 Subhalo Destruction Factor of 4 at small radii Kelley + In prep!11

12 Infall times Kelley + In prep!12

13 Halo pericenters Kelley + In prep!13

14 Radial distribution of Satellites Kelley + In prep!14

15 Radial distribution of Satellites Kelley + In prep!15

16 Radial distribution of Satellites!16

17 Dark fraction of galaxies Ocvirk+2017!17

18 Dark fraction of galaxies Vmax ~ 20 km s -1 Ocvirk+2017!18

19 Dark fraction of galaxies Vmax ~ 10 km s -1 Ocvirk+2017!19

20 Dark Fraction of Galaxies!20

21 Radial distributions!21

22 Radial distributions!22

23 Radial distributions!23

24 Radial distributions!24

25 Radial distributions!25

26 How do we solve this?!26

27 How do we solve this? Satellites fell in with the LMC?!27

28 How do we solve this? Satellites fell in with the LMC? Change how ultrafaints form? - Changing the timing of reionization?!28

29 How do we solve this? Satellites fell in with the LMC? Change how ultrafaints form? - Changing the timing of reionization? Subhalo destruction is too aggressive?!29

30 How do we solve this? Satellites fell in with the LMC? Change how ultrafaints form? - Changing the timing of reionization? Subhalo destruction is too aggressive? Thanks!!30