1. CWRU, February 2009 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

2. CWRU, February 2009 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  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)

3. CWRU, February 2009 WMAP Haze  Excess Free-Free emission from hot gas (T~10 5 K)  Gas thermally unstable  Insufficient gas abundance at 10 4 K (recombination lines) or 10 6 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~10 5 K)  Gas thermally unstable  Insufficient gas abundance at 10 4 K (recombination lines) or 10 6 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)

4. CWRU, February 2009 CMB Estimators  Internal Linear Combination (ILC)  Adopted by previous studies (e.g. Hooper, Finkbeiner & Dobler (2007), Finkbeiner & Dobler (2007) )  Gibbs Sampling  CMB maps are a by-product of the Gibbs sampling method of parameter estimation.  MCMC method that generates posterior samples of the signal map, power spectrum and foreground components.  Reliable because it is the output of a well understood statistical process known to provide good results.  Internal Linear Combination (ILC)  Adopted by previous studies (e.g. Hooper, Finkbeiner & Dobler (2007), Finkbeiner & Dobler (2007) )  Gibbs Sampling  CMB maps are a by-product of the Gibbs sampling method of parameter estimation.  MCMC method that generates posterior samples of the signal map, power spectrum and foreground components.  Reliable because it is the output of a well understood statistical process known to provide good results.

5. CWRU, February 2009 Foregrounds: 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) CWRU, February 2009

6. Foregrounds: 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

7. CWRU, February 2009 Foregrounds: 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

8. CWRU, February 2009 Foregrounds: 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.)

9. CWRU, February 2009 Template Fitting Solve Matrix Equation: Pa = w

10. CWRU, February 2009 Template Fitting  P ≠square  P ≠ linearly independent rows  Minimise by solving for pseudoinverse P + P ≠invertible

11. CWRU, February 2009 3-template fit  Multi-linear regression of free-free, dust and synchrotron templates  N side =64  Beam Width=3  Determined by Gibbs Sampling  Residual Map  r=Pa-wr=Pa-w (Gibbs)(ILC) Unwanted sources

12. CWRU, February 2009 3-template fit  Remove point sources, re-fit … (K-Band)(Ka-Band) (Q-Band)

13. CWRU, February 2009 3-template fit Introduce  2 : (K-Band)(Ka-Band) (Q-Band)  2 K = 5.54 (6.59),  2 Ka = 0.88 (1.45),  2 Q = 1.08 (2.12) [Full-Sky]   2 >1 significant  2 K = 14.69 (16.59),  2 Ka = 1.65 (2.42),  2 Q = 1.60 (2.84) [< 50  ]

14. CWRU, February 2009  Using ratios of elements of a   Using ratios of elements of a  3-template fit

15. CWRU, February 2009  Correlation Matrix: 3-template fit  Haze is correlated with Synchrotron Emission

16. 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  50°k  Allow for spatial variation in  sync. 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  50°k  Allow for spatial variation in  sync. by using multiple templates… 3-template fit  = 50 

17. CWRU, February 2009  Minimise  2 red. w.r.t.  using two Synchrotron templates 4-template fit (ILC)(Gibbs)

18. CWRU, February 2009 4-template fit (K-Band)(Ka-Band) (Q-Band) ∆  2 K (%)=20.0 (18.7), ∆  2 Ka (%) =7.7 (6.8), ∆  2 Q (%)=6.3 (4.9) [FS] ∆  2 K (%)=46.0(45.5), ∆  2 Ka (%) =24.8(24.9), ∆  2 Q (%)=25.2(22.0) [<50  ]

19. CWRU, February 2009  Using ratios of elements of a for synchrotron components   Using ratios of elements of a for synchrotron components  4-template fit

20. CWRU, February 2009 Dark 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

21. CWRU, February 2009  Neutralino DM (LSP): Neutralino Models  4 Benchmark models:  (Gaugino) (Higgsino) (Mixed)

22. CWRU, February 2009  Solve diffusion-loss equation: Steady-State e +/- distribution  Charged particles undergo random walk  Cylindrical (uniform) diffusion zone of depth 2L  Assume no re-acceleration of solar modulation

23. CWRU, February 2009 Steady-State e +/- distribution

24. CWRU, February 2009 Steady-State e +/- distribution

25. CWRU, February 2009 Synchrotron Radiation Spectrum  e +/- accelerated by galactic B-field, confined to helical paths  Lorentz factor  =E/m e  isotropic distribution of pitch angles 

26. CWRU, February 2009 Synchrotron Radiation Spectrum Only e +/- with  2 > / B (i.e. x 12GeV) contribute significantly

27. CWRU, February 2009 Synchrotron Radiation Spectrum

28. CWRU, February 2009 DM Synchrotron Flux Synchrotron Power for individual e +/-  Integrate along l.o.s. with inclination  wrt GC

29. CWRU, February 2009 Results for DM Synchrotron Flux  Significant Boost Factors (BF) required for Haze!

30. CWRU, February 2009 Summary  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.