matteo viel- warm dark matter and structure formation
TRANSCRIPT
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
1/30
MATTEO VIEL
WARM DARK MATTER AND STRUCTURE FORMATION
INAF and
INFN Trieste
(Italy)
ENTApP, DESY, Hamburg (Germany) - 25th February 2008
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
2/30
Intergalactic Medium + first stars +
Dwarf galaxies + cluster
Credit: NASA
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
3/30
OUTLINE
Impact of warm dark matter particles on structure formation
- Dark matter haloes and galaxies
- IGM and the Lyman- forest
Natarajan: impact on first stars
Ruchayskiy: X-ray constraints
Pieri: Substructures and dark matter
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
4/30
WARM DARK MATTER
HALOES
Smoothing of halo coresLower characteristic density
Late (z
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
5/30
Dark Matter projected density
Bode, Ostriker & Turok 2001
z=3
z=2
z=1
CDM m = 350 eV m = 175 eV
5 keV
0.2 keV
~ 1
~
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
6/30
Number of dark matter haloes
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
7/30
Number of dark mattersatellites as a function of
parent halo mass
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
8/30
Halo-density profilessteeper than NFW with sterile of
0.5 keV?
Colin, Valenzuela, Avila-Reese (2008)
R (kpc/h)
Haloes A and B close to the filtering
Mass 3x10 12 Msun
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
9/30
Concentration (ratio of the halo radiusand radius which contains 1/5 of the mass)
of host haloes is smaller in WDM than CDM
Colin, Valenzuela, Avila-Reese (2008)
1. In WDM the accretion/formation rate of guest haloes is smaller than CDM
2. In WDM the destruction rate of guest haloes is more efficient than CDM
In WDM models the haloes tend to form later when the universe is denser: c is lower
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
10/30
Wang & White 2007
Numerical artifacts?
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
11/30
Anomalous flux ratios in strong
QUASAR gravitational lensing
(cusp configuration)
Miranda & Maccio 2007
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
12/30
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
13/30
Strigari et al. 2007
You cannot put dwarf galaxies in the most massive subhaloes..
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
14/30
Strigari et al 2008
Common mass scale 2x107 Msun this correspond to a thermal mass
of ~ 6 keV
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
15/30
Strigari et al 2006 Fitting of the Fornax dSph core 5 globular clusters
whose evolution could be explained (?) by a core of 1.5 kpc
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
16/30
Simon & Geha 2007
8 ultra-faint dwarf galaxies
If galaxy formation in low-mass dark matterhaloes is strongly suppressed after reionization
there are still a factor of ~4 too few dwarf
galaxies compared to CDM
m > 3.16 keV
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
17/30
GAS
Intergalactic Medium: afaithful tracer of dark matter at
high-z and small scales
Inanu
tshe
ll
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
18/30
80 % of the baryons at z=3are in the Lyman- forest
baryons as tracer of the dark
matter density field
IGM ~ DM at scales larger than the
Jeans length ~ 1 com Mpc
-
Bi & Davidsen (1997), Rauch (1998)
THEORY
DATA
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
19/30
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
20/30
Lyman- and Warm Dark Matter - I
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
21/30
Lyman- and Warm Dark Matter - I
CDM GAS WDM GAS 0.5 keV
30 comoving Mpc/h z=3
MV, Lesgourgues, Haehnelt, Matarrese, Riotto, PRD, 2005, 71, 063534
k FS ~ 5 Tv/Tx (m x/1keV) Mpc-1
In general
Set by relativistic degrees of freedom at decoupling
See Colombi, Dodelson, Widrow, 1996Colin, Avila-Reese, Valenzuela 2000Bode, Ostriker, Turok 2001
Abazajian, Fuller, Patel 2001Wang & White 2007Colin, Avila-Reese, Valenzuela 2008
Lyman- and Warm Dark Matter - II
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
22/30
Lyman and Warm Dark Matter II
CDM
MV, Lesgourgues, Haehnelt, Matarrese, Riotto, PRD, 2005, 71, 063534
[P (k) WDM/P (k) CDM ]1/2
P(k) = A kn T2 (k)
Tx 10.75
=
T g (TD)
1/3
1/3
Light gravitino contributingto a fraction of dark matter
Warm dark matter
10 eV
100eV
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
23/30
Lyman- and Warm Dark Matter - IV
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
24/30
mWDM
> 550 eV thermal
> 2keV sterile neutrino
WDM CWDM
(gravitinos)
neutrinos
Lyman and Warm Dark Matter IV
Viel et al. (2005)from high-res
z=2.1 sample
Seljak, Makarov, McDonald, Trac, PhysRevLett, 2006, 97, 191303
mWDM
> 1.5-2 keV thermal
> 10-14 keV sterile neutrino
MATTER FLUX
FLUX FLUX
MV, Lesgourgues, Haehnelt, Matarrese, Riotto, PhysRevLett, 2006, 97, 071301
Lyman- and Warm Dark Matter - V
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
25/30
MV et al., Phys.Rev.Lett. 100 (2008) 041304
Tightest constraints on mass ofWDM particles to date:
m WDM > 4 keV (early decoupled
thermal relics)
m sterile > 28 keV
SDSS + HIRES data
SDSS range Completely new small scale regime
Lyman and Warm Dark Matter V
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
26/30
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
27/30
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
28/30
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
29/30
-
8/3/2019 Matteo Viel- Warm Dark Matter and Structure Formation
30/30