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Quasars and Low Surface Brightness Galaxies as Probes of Dark Matter Erik Zackrisson.

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Presentation on theme: "Quasars and Low Surface Brightness Galaxies as Probes of Dark Matter Erik Zackrisson."— Presentation transcript:

1 Quasars and Low Surface Brightness Galaxies as Probes of Dark Matter Erik Zackrisson

2 Outline Dark matter Dark matter Dark matter halos Dark matter halos Baryonic and non-baryonic dark matter Baryonic and non-baryonic dark matter Cold dark matter Cold dark matter Quasars Quasars Gravitational lensing Gravitational lensing Redshift Redshift Low Surface Brightness Galaxies Low Surface Brightness Galaxies Rotation curves Rotation curves Summary of Results Summary of Results

3 Dark matter Luminous matter Dark Matter

4 First detection of dark matter Fritz Zwicky (1933): Dark matter in the Coma Cluster

5 The Dark Matter Problem ~2% (Luminous) ~98% (Dark)

6 Dark Matter Halos I Galaxy  Stars + Gas + Dust + Supermassive Black Hole + Dark Matter

7 Dark Matter Halos II Luminous galaxy Dark halo

8 Baryonic & Non-Baryonic Dark Matter Baryonic matter: ~15% Example: Stars, gas clouds, planets… Example: Stars, gas clouds, planets… Missing: ~ 35% Missing: ~ 35% Non-baryonic matter: ~85% Example: Axions, neutralinos, Example: Axions, neutralinos, primordial black holes… primordial black holes… Missing: ~ 100% Missing: ~ 100% Best model: Cold Dark Matter (CDM) Best model: Cold Dark Matter (CDM)

9 Cold dark matter and the evolution of structure

10 Cold dark matter and the evolution of structure II

11 Cold Dark Matter Halos R R Dark matter halo Density Central density cusp predicted by cold dark matter Observed

12 Quasars

13

14 Gravitational lensing

15 Gravitational lensing II

16 Microlensing Made Simple Obs! Fel bild!

17 Microlensing Made Simple II

18 Claim: The long-term optical variability of quasars is quased by microlensing Hawkins, M.R.S. (1993, 1996, 1997, 2000, 2001, 2002, 2003)

19 The dark matter puzzle solved? M compact  M solar Almost all of the dark matter in this form Primordial black holes?

20 Expansion of the Universe

21 Redshifts High z  Large distance Low z  Small distance

22 Claims of non-cosmological redshifts Low-z galaxy surrounded by overdensity of high-z quasars Low-z galaxy with pairs of high-z quasars (with z 1  z 2 ) aligned along minor axis z1z1 z2z2

23 Ejection scenarios Local galaxy, very low redshift (z 1 ) Faint quasar, high redshift (>>z 1 ) Bright quasar, low redshift (>z 1 ) New galaxy (?), very low redshift (z 1 ) ? ? ? ? ?

24 Low Surface Brightness Galaxies The Very Large Telescope Examples of Target Galaxies

25 The Central Mass Budget Low Surface Brightness Galaxies High Surface Brightness Galaxies Dark matter Luminous matter Dark matter Luminous matter

26 Rotation Curves Radius V rot Radius Density Spectroscopy → Rotation Curve → Density Profile CDM prediction Observed

27 Results Paper I Uncertainties in the typical quasar size  Quasar variability cannot easily be used to constrain dark matter at the current time Uncertainties in the typical quasar size  Quasar variability cannot easily be used to constrain dark matter at the current time Paper II Microlensing cannot explain the long-term optical variability of quasars – Hawkins is wrong! Microlensing cannot explain the long-term optical variability of quasars – Hawkins is wrong! Paper III Non-cosmological redshift scenarios involving quasar ejection can be tested with observations of quasar host galaxies made a small telescope Non-cosmological redshift scenarios involving quasar ejection can be tested with observations of quasar host galaxies made a small telescope

28 Results II Paper IV The bluest low surface brightness galaxies can be used to test hierarchical galaxy formation models – provided that we can derive their ages The bluest low surface brightness galaxies can be used to test hierarchical galaxy formation models – provided that we can derive their ages The star formation rate of the bluest low surface brightness galaxies cannot have been constant or increasing – unless the stellar initial mass function is unusual The star formation rate of the bluest low surface brightness galaxies cannot have been constant or increasing – unless the stellar initial mass function is unusual Paper V The density profiles of the dark halos surrounding the bluest low surface brightness galaxies are in conflict with the Cold Dark Matter predictions The density profiles of the dark halos surrounding the bluest low surface brightness galaxies are in conflict with the Cold Dark Matter predictions

29 Errata Spikblad: Polhemssalen  Polhemsalen Spikblad: Polhemssalen  Polhemsalen Page v: optical long-term  long-term optical Page v: optical long-term  long-term optical Page 3: as the ray crossed  as its ray grazed Page 3: as the ray crossed  as its ray grazed Page 24 (twice): reflectance  reflection Page 24 (twice): reflectance  reflection Page 33: z  2—3  z  2—4 Page 33: z  2—3  z  2—4 Page 35: the latter variations  these variations Page 35: the latter variations  these variations Page 35: hoever are  are however Page 35: hoever are  are however Page 37: by fast rise  by a fast rise Page 37: by fast rise  by a fast rise Page 44: —10 14 m  —3  m Page 44: —10 14 m  —3  m Page 56: disk by  disk is given by Page 56: disk by  disk is given by Page 69: ett par procent  några få procent Page 69: ett par procent  några få procent Page 69: välkända astronomiska objekt  välkända typer av astronomiska objekt Page 69: välkända astronomiska objekt  välkända typer av astronomiska objekt Page 69: både vår och andra  både vår egen och andra Page 69: både vår och andra  både vår egen och andra Paper I, page 26, column 2, paragraph 1: higher angular size distance  higher light travel time distance Paper I, page 26, column 2, paragraph 1: higher angular size distance  higher light travel time distance Paper V, page 8: Division line should not be dashed Paper V, page 8: Division line should not be dashed


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