Slide Deck - There is No Missing Satellites Problem

A critical challenge to the cold dark matter (CDM) paradigm is that there are fewer satellites observed around the Milky Way than found in simulations of dark matter substructure. We show that there is a match between the observed satellite counts corrected by the detection efficiency of the Sloan Digital Sky Survey (for luminosities L≳ 340 L⊙) and the number of luminous satellites predicted by CDM, assuming an empirical relation between stellar mass and halo mass. The "missing satellites problem", cast in terms of number counts, is thus solved. We also show that warm dark matter models with a thermal relic mass smaller than 4 keV are in tension with satellite counts, putting pressure on the sterile neutrino interpretation of recent X-ray observations. Importantly, the total number of Milky Way satellites depends sensitively on the spatial distribution of satellites, possibly leading to a "too many satellites" problem. Measurements of completely dark halos below 10^8 M⊙, achievable with substructure lensing and stellar stream perturbations, are the next frontier for tests of CDM.

Transcript

1. Stacy Kim, Annika H. G. Peter, Jonathan Hargis there is no missing satellites problem GAIA DR1 sky map DES DR1 Workshop 2018
2. dark matter only simulations ~100 satellites Garrison-Kimmel+ 2017
3. LMC SMC Fornax Sculptor Draco Ursa Minor Carina Sextans Leo I Leo II Sagittarius GAIA DR1 sky map ~10 satellites! observed
4. LMC SMC Fornax Sculptor Draco Ursa Minor Carina Sextans Leo I Leo II Sagittarius GAIA DR1 sky map missing satellites problem observed ~10 satellites!
5. LMC SMC Fornax Sculptor Draco Ursa Minor Carina Sextans Leo I Leo II Sagittarius GAIA DR1 sky map observed ~27 post-SDSS
6. LMC SMC Fornax Sculptor Draco Ursa Minor Carina Sextans Leo I Leo II Sagittarius GAIA DR1 sky map observed ~44 with DES
7. LMC SMC Fornax Sculptor Draco Ursa Minor Carina Sextans Leo I Leo II Sagittarius GAIA DR1 sky map observed ~50 with DES + a few others
8. Tollerud+ 2008 where’s the rest?
9. Tollerud+ 2008 where’s the rest? Milky Way radius
10. Tollerud+ 2008 where’s the rest? visible
11. Tollerud+ 2008 where’s the rest? invisible visible
12. Tollerud+ 2008 where’s the rest? invisible visible MW satellites
13. completeness corrections
14. completeness corrections r (kpc) 1 0 radial distribution (plotted as a CDF) percent observed within r
15. completeness corrections for each dwarf observed, with luminosity MV , completeness
16. completeness corrections for each dwarf observed, with luminosity MV , completeness
17. completeness corrections for each dwarf observed, with luminosity MV , completeness
18. completeness corrections for each dwarf observed, with luminosity MV , completeness
19. completeness corrections for each dwarf observed, with luminosity MV , completeness
20. completeness corrections for each dwarf observed, with luminosity MV , completeness
21. completeness corrections for each dwarf observed, with luminosity MV , sum for
22. 101 102 r (kpc) 10 3 10 2 10 1 100 N(<r)/Ntotal Segue I NFW SIS ELVIS, stripped D17 DMO + gal DMO + gal + GK17 stripping radial distributions
23. total MW dwarfs, corrected based on SDSS DR 8
24. predictions from simulations
25. predictions from simulations luminous subhalos galaxies unsuppressed
26. predictions from simulations mass of Segue I based on SMHM relations
27. predictions from simulations mass of Segue I based on SMHM relations CDM predicts
28. total MW dwarfs, corrected
29. total MW dwarfs, corrected
30. total MW dwarfs, corrected no missing satellites! …if not too many
31. total MW dwarfs, corrected 10-100 satellites for DES based on radial distribution
32. 103 104 105 106 107 108 109 M⇤ (M ) 100 101 102 103 Nsats > M⇤ observed observed + area cor. NFW SIS ELVIS, stripped D17 DMO + gal DMO + gal + GK17 stripping Behroozi+ 2013 Moster+ 2013 Brook+ 2014 Behroozi+ 2013 Moster+ 2013 Brook+ 2014 corrected luminosity function
33. insights on dark matter
34. insights on dark matter
35. insights on dark matter could constrain
36. insights on dark matter could constrain
37. missing satellites: a summary no missing satellites problem if completeness corrections and reionization taken into account
38. missing satellites: a summary no missing satellites problem if completeness corrections and reionization taken into account places stringent constraints on dark matter models WDM thermal relic mass likely < 4 keV 7 keV sterile neutrino highly likely to be ruled out!
39. missing satellites: a summary no missing satellites problem if completeness corrections and reionization taken into account new frontier for tests of CDM is 108 M¤ places stringent constraints on dark matter models WDM thermal relic mass likely < 4 keV 7 keV sterile neutrino highly likely to be ruled out!
40. EXTRAS: MSP
41. 103 104 105 106 107 108 109 M⇤ (M ) 100 101 102 103 Nsats > M⇤ observed observed + area cor. NFW SIS ELVIS, stripped D17 DMO + gal DMO + gal + GK17 stripping Behroozi+ 2013 Moster+ 2013 Brook+ 2014 Behroozi+ 2013 Moster+ 2013 Brook+ 2014 corrected luminosity function
42. 103 104 105 106 107 108 109 M⇤ (M ) 100 101 102 103 Nsats > M⇤ observed observed + area cor. NFW SIS ELVIS, stripped D17 DMO + gal DMO + gal + GK17 stripping zre = 9.3 zre = 11.3 zre = 14.4 zre = 9.3 zre = 11.3 zre = 14.4 corrected luminosity function
43. 100 101 102 103 cumulative number of satellites < Minfall 107 108 109 1010 1011 infall mass (M ) Brook+ 2014 Moster+ 2013 Behroozi+ 2013 CDM WDM, 8.0 keV WDM, 4.0 keV WDM, 2.0 keV WDM, 1.0 keV corrected luminosity function
44. 106 107 108 109 Lowest mass galaxy halo (Minfall /M ) NFW SIS ELVIS, stripped DMO + gal DMO + gal, GK17 stripping MSP not enough subhalos 106 107 108 hMz=0 i/M mass of Segue I z = 9.3
45. 106 107 108 109 Lowest mass galaxy halo (Minfall /M ) NFW SIS ELVIS, stripped DMO + gal DMO + gal, GK17 stripping MSP not enough subhalos 106 107 108 hMz=0 i/M mass of Segue I z = 11.3
46. 106 107 108 109 Lowest mass galaxy halo (Minfall /M ) NFW SIS ELVIS, stripped DMO + gal DMO + gal, GK17 stripping MSP not enough subhalos 106 107 108 hMz=0 i/M mass of Segue I z = 14.4