can the wmap haze really be a signature of annihilating neutralino dark matter?
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Can the WMAP haze really be a signature of annihilating neutralino dark matter?. Daniel Cumberbatch (CWRU), Joe Zuntz (Oxford), Joe Silk (Oxford) and Hans Kristian Kamfjord Eriksen (Oslo). arXiv:0902.0039. Wilkinson Microwave Anisotropy Probe (WMAP). Cosmic Microwave Background (CMB) - PowerPoint PPT PresentationTRANSCRIPT
CWRU, February 2009
Can the WMAP haze really be a signature of annihilating neutralino dark matter?
Can the WMAP haze really be a signature of annihilating neutralino dark matter?
Daniel Cumberbatch (CWRU), Joe Zuntz (Oxford),
Joe Silk (Oxford) and Hans Kristian Kamfjord Eriksen (Oslo)
Daniel Cumberbatch (CWRU), Joe Zuntz (Oxford),
Joe Silk (Oxford) and Hans Kristian Kamfjord Eriksen (Oslo)
arXiv:0902.0039
CWRU, February 2009
Wilkinson Microwave Anisotropy Probe (WMAP)
Wilkinson Microwave Anisotropy Probe (WMAP)
Cosmic Microwave Background (CMB) Temperature anisotropies Polarization anisotropies Cosmological parameter estimation
Cosmic Microwave Background (CMB) Temperature anisotropies Polarization anisotropies Cosmological parameter estimation
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Galactic Foregrounds Requires estimation before CMB signal extraction Multiple sources Dominant foregrounds:
Free-Free (Thermal Bremsstrahlung) Thermal Dust Synchrotron
Minimized in WMAP range (23 < < 94 GHz)
CWRU, February 2009
WMAP HazeWMAP Haze Excess Free-Free emission from hot gas (T~105 K)
Gas thermally unstable Insufficient gas abundance at 104 K (recombination lines) or 106 K (X-rays).
Exotic Sources of synchrotron emission Ultra-relativistic electrons from supernovae Dark Matter annihilation
SUSY neutralinos (Hooper ‘07) Exciting DM (XDM) (Weiner ‘08) Compact Composite Objects (CCO’s) (Zhitnitsky ‘08) Sommerfeld-enhanced DM (Lattanzi ‘08)
Excess Free-Free emission from hot gas (T~105 K) Gas thermally unstable Insufficient gas abundance at 104 K (recombination lines) or 106 K (X-rays).
Exotic Sources of synchrotron emission Ultra-relativistic electrons from supernovae Dark Matter annihilation
SUSY neutralinos (Hooper ‘07) Exciting DM (XDM) (Weiner ‘08) Compact Composite Objects (CCO’s) (Zhitnitsky ‘08) Sommerfeld-enhanced DM (Lattanzi ‘08)
CWRU, February 2009
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Foregrounds: Free-FreeForegrounds: Free-Free
Free-Free (or thermal Bremsstrahlung) emission Coulomb interactions between free e- and hot interstellar gas Maps of H recombination line emission EM H maps can trace morphology of Free-Free emission
Wisconsin H Mapper (WHAM) Southern H Sky Survey Atlas (SHASSA) Virginia Tech Spectral-Line Survey (VTSS)
Free-Free (or thermal Bremsstrahlung) emission Coulomb interactions between free e- and hot interstellar gas Maps of H recombination line emission EM H maps can trace morphology of Free-Free emission
Wisconsin H Mapper (WHAM) Southern H Sky Survey Atlas (SHASSA) Virginia Tech Spectral-Line Survey (VTSS)
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I ∝ ne2dl∫ = Emission Measure (EM)
CWRU, February 2009
CWRU, February 2009
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Foregrounds: Free-FreeForegrounds: Free-Free
Correct H map for dust-extinction assume uniform mixing of warm gas and dust in E(B-V) magnitudes Mask out regions A(H)=2.65E(B-V)>1
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τ =2.65 /1.086*SFD
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⇒ Iv,obs. = Iv,em.(1− e−τ ) /τ
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T ∝ v−2.15
CWRU, February 2009
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Foregrounds: DustForegrounds: Dust
Thermal dust emission Microscopic dust grains vibrating in thermal equilibrium
with ambient radiation field Finkbeiner Davis and Schlegel (FDS) @ 94 GHz may also
trace electric dipole emission from smallest dust grains Excited into rotational modes by collisions with ions
Thermal dust emission Microscopic dust grains vibrating in thermal equilibrium
with ambient radiation field Finkbeiner Davis and Schlegel (FDS) @ 94 GHz may also
trace electric dipole emission from smallest dust grains Excited into rotational modes by collisions with ions
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Ttherm. ∝ v +1.3
Tspin ∝ v−2.85
CWRU, February 2009
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Foregrounds: SynchrotronForegrounds: Synchrotron
Mainly from e- near supernovae explosions Shock-accelerated to relativistic (i.e. >MeV) energies Subsequently lose energy from ICS (Starlight or CMB)
and Synchrotron emission (Galactic Magnetic Field) Measured best at v <1 GHz Full-sky map at 408 MHz (Haslam et al.)
Mainly from e- near supernovae explosions Shock-accelerated to relativistic (i.e. >MeV) energies Subsequently lose energy from ICS (Starlight or CMB)
and Synchrotron emission (Galactic Magnetic Field) Measured best at v <1 GHz Full-sky map at 408 MHz (Haslam et al.)
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−2.3 < β < −3.05
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T ∝ v β
CWRU, February 2009
Template FittingTemplate Fitting
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P =
P1
P2
P3
P4
P5
⎛
⎝
⎜ ⎜ ⎜ ⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟ ⎟ ⎟ ⎟
Solve Matrix Equation: Pa = w
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Pi =
f1,i d1,i s1,i
f2,i d2,i s2,i
. . .
. . .
. . .
fN p ,i dN p ,i sN p ,i
⎛
⎝
⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟€
⇑
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w =
T1,1 − c1
T2,1 − c2
.
.
.
T1,2 − c1
.
.
.
TN p ,5 − cN p
⎛
⎝
⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟
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a =
a f ,1
ad ,1
as,1
a f ,2
ad ,2
as,2
.
.
.
as,5
⎛
⎝
⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟
CWRU, February 2009
Template Fitting
P ≠square P ≠ linearly independent rows
Minimise
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χ 2 =P
σa −
w
σ by solving for pseudoinverse P+
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a = P+w€
} P ≠invertible
CWRU, February 2009
3-template fit3-template fit Multi-linear regression of free-free, dust and synchrotron templates Multi-linear regression of free-free, dust and synchrotron templates
Nside=64
Beam Width=3
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} Determined by Gibbs Sampling
Residual Map r=Pa-w
(Gibbs) (ILC)
Unwanted sources
CWRU, February 2009
3-template fit3-template fit Remove point sources, re-fit … Remove point sources, re-fit …
(K-Band) (Ka-Band)
(Q-Band)
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χ red.2 =
χ 2
v, v = N p − Na
χ red.2 = 7.85 (Gibbs), 11.05 (ILC)
CWRU, February 2009
3-template fit3-template fitIntroduce 2:Introduce 2:
(K-Band) (Ka-Band) (Q-Band)
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2 =1
N p
ζ i, j2 =
1
N p
x i, j − xi( )
2
σ i, j2
j=1
N p
∑j=1
N p
∑
2K = 5.54 (6.59), 2
Ka = 0.88 (1.45), 2Q = 1.08 (2.12) [Full-Sky]
2>1 significant
2K = 14.69 (16.59), 2
Ka = 1.65 (2.42), 2Q = 1.60 (2.84) [< 50]
CWRU, February 2009
Using ratios of elements of a
Using ratios of elements of a
3-template fit
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Iv ∝ v β
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+1.14 (+1.23) < β dust < − 2.93 (−2.99)
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β ff = −1.93 (−1.80)
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βsync = −2.93 (−3.13)
CWRU, February 2009
Correlation Matrix: Correlation Matrix:
3-template fit
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φX,r =x i − x[ ] ri − r[ ]
x i − x[ ]2
ri − r[ ]2
Haze is correlated with Synchrotron Emission
CWRU, February 2009
Haze is statistically significant < 50 around GC Haze is correlated with Synchrotron emission
Exotic component (e.g. Dark Matter) ??? If so, would expect β<50° ≠ β>50°k
Allow for spatial variation in βsync. by using multiple templates…
Haze is statistically significant < 50 around GC Haze is correlated with Synchrotron emission
Exotic component (e.g. Dark Matter) ??? If so, would expect β<50° ≠ β>50°k
Allow for spatial variation in βsync. by using multiple templates…
3-template fit
= 50
CWRU, February 2009
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min . = 46.5o
χ red.,min.2 = 9.173 (17%)
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min . = 48.5o
χ red.,min.2 = 6.379 (16%)
Minimise χ2red. w.r.t. using two Synchrotron templates Minimise χ2red. w.r.t. using two Synchrotron templates
4-template fit
(ILC)(Gibbs)
CWRU, February 2009
4-template fit4-template fit(K-Band) (Ka-Band) (Q-Band)
∆2K(%)=20.0 (18.7), ∆ 2
Ka(%) =7.7 (6.8), ∆2Q(%)=6.3 (4.9) [FS]
∆2K(%)=46.0(45.5), ∆2
Ka(%) =24.8(24.9), ∆2Q(%)=25.2(22.0) [<50]
CWRU, February 2009
Using ratios of elements of a for synchrotron components
Using ratios of elements of a for synchrotron components
4-template fit
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Iv ∝ v β
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β>50o = −2.89 (−3.11)
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β<50o = −2.99 (−3.13)
CWRU, February 2009
Dark MatterDark Matter WIMP DM candidates annihilate to e+/- +…other SM particles DM annihilation Rate (r)2 hence increases towards GC
e+/- propagate ISM
e+/- interact with galactic magnetic field
e +/- radiate via synchrotron (i.e. Haze)
WIMP DM candidates annihilate to e+/- +…other SM particles DM annihilation Rate (r)2 hence increases towards GC
e+/- propagate ISM
e+/- interact with galactic magnetic field
e +/- radiate via synchrotron (i.e. Haze)
Ingredients for DM contribution: Calculate e+/- injection spectrum for WIMPs (i.e. per annihilation) Calculate steady-state e+/- distribution in the galactic halo Calculate fractional power of sync. rad. that e+/- of a given E
contributes to a given frequency (e.g. K-band, 23GHz) Calculate total flux radiated by e+/- along a given line of sight
Ingredients for DM contribution: Calculate e+/- injection spectrum for WIMPs (i.e. per annihilation) Calculate steady-state e+/- distribution in the galactic halo Calculate fractional power of sync. rad. that e+/- of a given E
contributes to a given frequency (e.g. K-band, 23GHz) Calculate total flux radiated by e+/- along a given line of sight
CWRU, February 2009
Neutralino DM (LSP): Neutralino DM (LSP):
Neutralino ModelsNeutralino Models
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χ10
~
= N11 B0~
+ N12 W30
~
+ N13 H10
~
+ N14 H20
~
4 Benchmark models:
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mχ = 50 GeV, B(χχ → bb) = 0.96, B(χχ → τ +τ −) = 0.04
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mχ =150 GeV, B(χχ → bb) = 0.96, B(χχ → τ +τ −) = 0.04
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mχ = 600 GeV, B(χχ → bb) = 0.87, B(χχ → τ +τ −) = 0.13
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mχ =150 GeV, B(χχ → W +W −) = 0.58, B(χχ → Z 0Z 0) = 0.42
(Gaugino)
(Gaugino)
(Higgsino)
(Mixed)
CWRU, February 2009
Solve diffusion-loss equation: Solve diffusion-loss equation:
Steady-State e+/- distributionSteady-State e+/- distribution
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Q(ε,r)∝σv
mχ2 ρ(r)2 dφ
dε
Charged particles undergo random walk Cylindrical (uniform) diffusion zone of depth 2L Assume no re-acceleration of solar modulation
CWRU, February 2009
Steady-State e+/- distributionSteady-State e+/- distribution
CWRU, February 2009
Steady-State e+/- distributionSteady-State e+/- distribution
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K = K0 = 9 ×1027cm s-1,τ E =1016s, L =10kpc, (α ,β ,γ) = (1,3,1), rs = 20kpc, ρ s = 5.6 ×10−25g cm-3
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mχ = 50 GeV, B(χχ → e+e−) =1
σv = 2 ×10−26cm3s−1
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mχ = 50 GeV, B(χχ → bb) = 0.96,
B(χχ → τ +τ −) = 0.04, σv = 2.7 ×10−26cm3s−1
CWRU, February 2009
Synchrotron Radiation SpectrumSynchrotron Radiation Spectrum e+/- accelerated by galactic B-field, confined to helical paths Lorentz factor =E/me
isotropic distribution of pitch angles
CWRU, February 2009
Synchrotron Radiation SpectrumSynchrotron Radiation Spectrum
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B =10μG, vobs. = 22.8 GHz (K - band)
Only e+/- with 2>/B (i.e. x<1, E>12GeV) contribute significantly
CWRU, February 2009
Synchrotron Radiation SpectrumSynchrotron Radiation Spectrum
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mχ = 50 GeV, B(χχ → bb) = 0.96,
B(χχ → τ +τ −) = 0.04, σv = 2.7 ×10−26cm3s−1
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mχ = 50 GeV, B(χχ → e+e−) =1
σv = 2 ×10−26cm3s−1
CWRU, February 2009
DM Synchrotron FluxDM Synchrotron Flux
Synchrotron Power for individual e+/-
Integrate along l.o.s. with inclination wrt GC
CWRU, February 2009
Results for DM Synchrotron FluxResults for DM Synchrotron Flux
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K0 =1028cm2s−1,α = 0.33,τ E = 2 ×1015s, f sync. = 0.25,B =10μG,L = 3kpc
Significant Boost Factors (BF) required for Haze!
CWRU, February 2009
SummarySummary There is a statistically significant residual emission surrounding
GC remaining after fitting Free-Free, Dust and Sync. foregrounds. Largely consistent results between Gibbs and ILC CMB
estimators. Haze can be significantly reduced by allowing for a slight spatial
dependence in Synchrotron emission within 50° of GC, with a similar spectral dependence as that further out.
The DM contribution to the Haze depends sensitively on its fractional power to synchrotron emission for e+/- with
2>/B .
DM requires significant boosting in Synchrotron power
(BF~100-1000) in order to account for Haze. BF~100 may be obtainable from Dark Matter Substructures.
There is a statistically significant residual emission surrounding GC remaining after fitting Free-Free, Dust and Sync. foregrounds.
Largely consistent results between Gibbs and ILC CMB estimators.
Haze can be significantly reduced by allowing for a slight spatial dependence in Synchrotron emission within 50° of GC, with a similar spectral dependence as that further out.
The DM contribution to the Haze depends sensitively on its fractional power to synchrotron emission for e+/- with
2>/B .
DM requires significant boosting in Synchrotron power
(BF~100-1000) in order to account for Haze. BF~100 may be obtainable from Dark Matter Substructures.