Theorem : Proof... Pavel Kroupa. Pavel Kroupa: AIfA, University of Bonn

Transcription

1 Theorem : dsph = TDG = LCDM Proof... Pavel Kroupa 1

2 Two Zwicky Conjectures of fundamental importance : 1. Zwicky (1937) galaxies are about 500 times heavier in the Coma galaxy cluster than judged from their light emission. This is his famous conjecture that there must be dark matter. 2. Zwicky (1956) : when galaxies interact (e.g. when they collide), the expelled matter can re-condense in regions and form new smaller (dwarf) galaxies. This is his famous conjecture that tidal-dwarf galaxies can form out of the collisional debris of other galaxies. Both have to be true... 2

3 the LCDM model Structures form according to the cosmological merger tree the beginning Lacey & Cole (1993) today 3

4 250 kpc by Zwicky's 1st conjecture Astrophysics of Galaxies VIII: LG 4

5 Structures form according to the cosmological merger tree the beginning Lacey & Cole (1993) by Zwicky's 2nd conjecture TDGs form today 5

6 (Weilbacher et al. 2000) N TDG 14 6

7 Fritz Zwicky's two conjectures have two immediate implications : 1. There exist large numbers of dark-matter dominated satellite galaxies (e.g. Moore et al., Klypin et al.). 2. There exist large numbers of newly formed (tidal-dwarf) satellite galaxies (they do not contain dark matter) (Okazaki & Taniguchi 2000). This is OK, but are there two different types of dwarf galaxy? 7

8 Radius vs luminosity : Dabringhausen, Hilker, Kroupa 2008; Misgeld & Hilker 2011 Forbes, Lasky, Graham, Spitler 2008 dsph satellite galaxies de galaxies E galaxies star clusters UCDs/ Hilker objects faint / low-mass 10 6 M 8 bright / massive 8

9 Radius vs luminosity : Dabringhausen, Hilker, Kroupa 2008; Misgeld & Hilker 2011 Forbes, Lasky, Graham, Spitler 2008 dsph satellite galaxies Our dwarfs of interest de galaxies E galaxies Gilmore gap star clusters UCDs/ Hilker objects M M faint / low-mass 10 6 M 9 bright / massive 9

10 Radius vs luminosity : Dabringhausen, Hilker, Kroupa 2008; Misgeld & Hilker 2011 Forbes, Lasky, Graham, Spitler 2008 dsph satellite galaxies Our dwarfs of interest de galaxies E galaxies Gilmore gap star clusters UCDs/ Hilker objects M M faint / low-mass 10 6 M 10 bright / massive 10

11 Radius vs luminosity : Dabringhausen, Hilker, Kroupa 2008; Misgeld & Hilker 2011 Forbes, Lasky, Graham, Spitler 2008 dsph satellite galaxies Our dwarfs of interest de galaxies E galaxies Gilmore gap star clusters t relax > τ Hubble = galaxies UCDs/ Hilker objects M M faint / low-mass 10 6 M 11 bright / massive 11

12 Fritz Zwicky's two conjectures have two immediate implications : 1. There exist large numbers of dark-matter dominated satellite galaxies. 2. There exist large numbers of newly formed (tidal-dwarf) satellite galaxies (they do not contain dark matter). This is OK, but are there two different types of dwarf galaxy? 12

13 No, there is only one type of dwarf galaxy! But, which one? And why only one? 13

14 Lets consider first the dark-matter type satellite dwarf galaxy. Test this idea with calculations within the LCDM framework: 14

15 The mass-luminosity relation : energy balance: more gravitating mass, more luminous mass? 15

16 The mass - luminosity relation of satellite galaxies expected κ > 0 log 20 (M 0.3 kpc /M ) = log 10 (M 03 /M )+κ log 10 (L V /L V, ) 16

17 The DM-mass--luminosity relation of satellite galaxies Theory - Models of Satellites Wadepuhl & Springel (2010) + many other groups Dark-matter models behave correctly expected κ > 0 L/Lsun 17

18 The DM-mass--luminosity relation of satellite galaxies Observations - empirical data of Satellites Observations observed : κ =0 expected κ > 0 Strigari et al. (2008) confirmed by Wolf et al. (2010) 18

19 Kroupa et al. (2010, A&A) A) Dekel & Silk (1986); Dekel &Woo (2003), stellar feedback; B) Busha et al. (2010), their SPS in-homogeneous re-ionisation; C) Macci`o et al. (2010), SAM; D) Okamoto & Frenk (2009), Aq-D-HR; E) 1 and 5 kev WDM model of Macci`o & Fontanot (2010); F) Aquarius sub-halo-infall models of Cooper et al. (2010). log 20 (M 0.3 kpc /M ) = log 10 (M 03 /M )+κ log 10 (L V /L V, ) 19

20 All model satellite populations have κ > 0 The lack of an observed mass-luminosity relation ( κ 0 ) nature apparently does not care about the existence of the putative dark matter halo. 20

21 Thus, the concept of dark-matter halos appears to be unphysical for dsph satellites dark-matter halos 21

22 Individual dsph morphology : DM gravitating potential : smooth luminous morphology? 22

23 Significant isophote structure is present in many dsph satellites despite a large σ 700 pc/100 Myr Substructure should smear-out if is really due to a DM halo, unless it has a harmonic core. σ consistent with DM halo? 23

24 ( M L ( M L UMi D=65kpc (Kleyna et al. 1998) ) ) 0,V tot,v (Mateo 1998) But : ( M L ) = 60 = 79 = 12 particles (Gomez-Flechoso & Martinez-Delgado 2003) 24

25 UMi D=65kpc (Martinez-Delgado et al., in prep) Substructure significant : (Kleyna et al. 2003) 25

26 UMi D=65kpc (Martinez-Delgado et al., in prep) S shape : strong evidence for extra-tidal stars Massive CDM halo? 26

27 Fornax D=140kpc (Demers et al. 1994) ( ) M L ( ) M L 0,V tot,v (Mateo 1998) =4.8 =4.4 Not consistent with being embedded / shielded by an extensive dark-matter subhalo! 27

28 Carina D=93kpc (Walcher et al. 2003) ( M L ( M L ) ) 0,V 0,V (Mateo 1998) = 30 = 31 28

29 Hercules D=130kpc (Coleman et al. 2007) 29

30 The distortions apparent in many of the dsph satellites do not support the notion that they are shielded by dark-matter halos M dark-matter halos 30

31 The spatial distribution of the MW satellites... further clues 31

32 Structures form according to the cosmological merger tree the beginning Lacey & Cole (1993) today 32

33 250 kpc Astrophysics of Galaxies VIII: LG 33

34 MW satellites are in a disk-like configuration: the 11 classical (brightest) satellites new satellites Kroupa et al. (2010, A&A) 34

35 MW satellites are in a disk-like configuration: the 11 classical (brightest) satellites new satellites Kroupa et al. (2010, A&A) N out N out N out N in N in N out 35

36 MW satellites are in a disk-like configuration: Kroupa et al. (2010, A&A) N in N out N in = N out 36

37 MW satellites are in a disk-like configuration: Kroupa et al. (2010, A&A) 37

38 MW satellites are in a disk-like configuration: Kroupa et al. (2010, A&A) 38

39 Thus, the 13 new ultra-faint and the 11 classical satellites independently define the same Disk of Satellites (DoS). 39

40 Disk of Satellites a rotational structure? the 11 classical (brightest) satellites new satellites Kroupa et al. (2010, A&A) inner satellites define { orbital angular momentum 40

41 the Galactic sky (Galactic spherical coordinates) Directions of orbital angular momentum Galactic equator South GP Pawlowski et al

42 the Galactic sky (Galactic spherical coordinates) Directions of orbital angular momentum South GP Pawlowski et al

43 Disk of Satellites a rotational structure? the 11 classical (brightest) satellites new satellites Kroupa et al. (2010, A&A) inner satellites define { orbital angular momentum } } n outer satellites define n normal to DoS 43

44 the Galactic sky (Galactic spherical coordinates) South GP Pawlowski et al

45 the Galactic sky (Galactic spherical coordinates) South GP Pawlowski et al

46 This correlated phase-space population is inconsistent with the satellites being dark-matter sub-haloes that fell into the MW halo in a group or individually. dark-matter halos 46

47 Logical inconsistencies within LCDM framework 47

48 Deason et al. (2011, MNRAS) (abstract): To get the DoS: "The satellite galaxies have been accreted relatively recently" Nichols & Bland-Hawthorn (2011, ApJ) ignore the DoS (abstract): Get gas-poor dsph around the Galaxy and M31: "if the dwarfs fell in at high redshifts (z~3-10)." 48

49 All these independent arguments The dark-matter ansatz fails. (no consistent natural solution has come forth) 49

50 Remember the two implications of Fritz Zwicky's two conjectures : 1. There exist large numbers of dark-matter dominated satellite galaxies 2. There exist large numbers of newly formed (tidal-dwarf) satellite galaxies. No, there is only one type of dwarf galaxy! But, which one? And why only one? 50

51 Lets consider now the tidal-dwarf type satellite dwarf galaxy : 51

52 Pioneering work by Tidal dwarf galaxies. Felix Mirabel, Pierre-Alain Duc, Frederic Bournaud, Francoise Combes, Olivier Tiret = "The French" And see also Barnes & Hernquist; Elmegreen; Wetzstein 52

53 Tidal tails Miho & Maxwell, web 53

54 54

55 (Weilbacher et al. 2000) N TDG 14 55

56 Relevance : The collision of two disks at high redshift Wetzstein, Naab & Burkert

57 Wetzstein, Naab & Burkert

58 Thus, by direct observation new dwarf galaxies with masses comparable to de/dsph galaxies form like shrapnel. They are baryon dominated (Barnes & Hernquist 1992). 58

59 Evolution of TDGs The Time 59 59

60 Evolve dwarf galaxies w/o dark matter in a computer 60

61 61

62 Star-cluster complex (cf Tadpole) 50 clusters each 10 6 M clusters as fundamental galactic building blocks Spheroidal dwarf galaxy! (Fellhauer et al. 2001, 2002a,b,c, 2005; Bekki et al. 2004) 62

63 1-10% of population in remnant 63

64 (Kroupa 1997) e =0.74 Remnants have a highly anisotropic f(r,v) and mass 10 5 M R few 100 pc M L 102 3! and e =

65 Hercules D=130kpc (Coleman et al. 2007) 65

66 Hercules D=130kpc (Coleman et al. 2007) 66

67 !{ (Kroupa 1997) very similar to Hercules M V = 9 mag r 0.5 = 180 pc M L =

68 This is a real prediction 10 years before the discovery of this type of celestial object! 68

69 For TDGs we know today that The early (<100Myr) star-formation and chemical enrichment evolution is similar to the observed dsph satellites. (Recchi et al. 2007) Later dynamical evolution does not destroy the satellites. (Kroupa 1997) The number of old TDGs amounts to the de population observed. (Okazaki & Taniguchi 2000) de galaxies are observed to contain no Dark Matter, consistent with them being TDGs. (Toloba et al. 2010, arxiv: v1) 69

70 What about the disklike configuration of MW satellites? the 11 classical (brightest) satellites new satellites Kroupa et al. (2010, A&A) 70

71 (Weilbacher et al. 2000) bulge formation Phase-space correlated satellites form naturally in the same event as a bulge does. TDG formation 71

72 ... and, a bulge mass vs number of satellites correlation? bulge 72

73 A bulge - satellite correlation Kroupa et al. (2010, A&A) 73

74 Both, the Disk of Satellites and the bulge--satellite correlation are naturally understandable if the MW satellites are ancient TDGs. (Kroupa et al. 2010) 74

75 Other extragalactic correlated dsph satellite systems 75

76 NGC 1097 s dog-leg tidal stream Galianni, Patat et al. (2010 A&A) NGC 1097A "Jet2" = dog leg is a stellar stream NGC

77 NGC 1097 s dog-leg tidal stream Galianni, Patat et al. (2010 A&A) Knot B Knot A (Kroupa et al. 2010) 77

78 NGC 5557 (post-merger 2-3 Gyr) Duc et al. (2011 MNRAS) 200 kpc dsph dsph Text dsph (Kroupa et al. 2010) 78

79 The observed and theoretical TDGs coincide with de galaxies! 79

80 Thus, (1) a fully self-consistent TDG scenario thus emerges which very naturally accounts for the properties of de and satellite galaxies; (2) no consistent, and in fact a contradictory picture emerges in the dark-matter framework; (3) there is simply no evidence for the existence of DM satellites. 80

81 Dark matter galaxies vs baryonic ones : why so similar? 81

82 Gentile et al., dark matter objects 2007} The Tully -Fisher Relation : 82

83 TDGs } dark matter objects But TDGs are purely baryonic objects. So, why are they so similar to the other galaxies? Gentile et al., 2007 The Tully -Fisher Relation and internal dynamics of young TDGs : 83

84 ... Summary & Conclusions... 84

85 The two Fritz Zwicky Conjectures : A. DM dominates large galaxies (postulate from kinematics). CONTRADICTION because B. New dwarf galaxies form in tidal debris (direct observational fact). 1. There must be many satellite galaxies with massive dark matter halos (type A dwarfs). 2. there must be many (tidal - dwarf) satellite galaxies without dark matter (type B dwarfs). But only one type of de / dsph galaxy is observed to exist. This can only be type B because this type is a consequence of well-known physical laws. The DoS and bulge-satellite correlation are additional, independent, supporting evidence. DISCARD Conjecture A. 85

86 I think, this is where we are seeing new physics worthy of exploration. 86

87 dsph = TDG = LCDM 87

88 The END 88