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: 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) 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 (CCOs) (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 (CCOs) (Zhitnitsky 08) Sommerfeld-enhanced DM (Lattanzi 08) 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. 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 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 CWRU, February 2009 Foregrounds: Dust Thermal dust emission Microscopic dust grains vibrating in thermal equilibrium with ambient radiation field Finkbeiner Davis and Schlegel 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 94 GHz may also trace electric dipole emission from smallest dust grains Excited into rotational modes by collisions with ions 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 MeV) energies Subsequently lose energy from ICS (Starlight or CMB) and Synchrotron emission (Galactic Magnetic Field) Measured best at v 1 significant 2 K = (16.59), 2 Ka = 1.65 (2.42), 2 Q = 1.60 (2.84) [< 50 ] CWRU, February 2009 Using ratios of elements of a Using ratios of elements of a 3-template fit CWRU, February 2009 Correlation Matrix: 3-template fit 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 50k 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 50k Allow for spatial variation in sync. by using multiple templates 3-template fit = 50 CWRU, February 2009 Minimise 2 red. w.r.t. using two Synchrotron templates 4-template fit (ILC)(Gibbs) CWRU, February 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) [ / B (i.e. x 12GeV) contribute significantly CWRU, February 2009 Synchrotron Radiation Spectrum CWRU, February 2009 DM Synchrotron Flux Synchrotron Power for individual e +/- Integrate along l.o.s. with inclination wrt GC CWRU, February 2009 Results for DM Synchrotron Flux Significant Boost Factors (BF) required for Haze! 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~ ) 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~ ) in order to account for Haze. BF~100 may be obtainable from Dark Matter Substructures.