A Last Look at the Microwave Haze/Bubbles with WMAP

Abstract

The microwave "haze" was first discovered with the initial release of the full sky data from the Wilkinson Microwave Anisotropy Probe. It is diffuse emission towards the center of our Galaxy with spectral behavior that makes it difficult to categorize as any of the previously known emission mechanisms at those wavelengths. With now seven years of WMAP data publicly available, we have learned much about the nature of the haze, and with the release of data from the Fermi Gamma-Ray Space Telescope and the discovery of the gamma-ray haze/bubbles, we have had a spectacular confirmation of its existence at other wavelengths. As the WMAP mission winds down and the Planck mission prepares to release data, I take a last look at what WMAP has to tell us about the origin of this unique Galactic feature. Much like the gamma-rays, the microwave haze/bubbles is elongated in latitude with respect to longitude by a factor of roughly two, and at high latitudes, the microwave emission cuts off sharply above ~35 degrees (compared to ~50 degrees in the gammas). The hard spectrum of electrons required to generate the microwave synchrotron is consistent with that required to generate the gamma-ray emission via inverse Compton scattering, though it is likely that these signals result from distinct regions of the spectrum (~10 GeV for the microwaves, ~1 TeV for the gammas). While there is no evidence for significant haze polarization in the 7-year WMAP data, I demonstrate explicitly that it is unlikely such a signal would be detectable above the noise.

9 pages, 6 figures; accepted in ApJ; matches published version with significantly enhanced figures

References in corpus (15)

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• Separation of anomalous and synchrotron emissions using WMAP polarization data
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• Fermi gamma-ray `bubbles' from stochastic acceleration of electrons
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• Constraining Spinning Dust Parameters with the WMAP Five-Year Data
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• Identification of Spinning Dust in Halpha-Correlated Microwave Emission
• The WMAP haze from the Galactic Center region due to massive star explosions and a reduced cosmic ray scale height
• Systematic effects in the extraction of the 'WMAP haze'

Cited by in corpus (32)

• The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter
• The Spectrum and Morphology of the Fermi Bubbles
• The Fermi Bubbles. I. Possible Evidence for Recent AGN Jet Activity in the Galaxy
• Dark Matter Evidence, Particle Physics Candidates and Detection Methods
• The Fermi Bubbles: Supersonic AGN Jets with Anisotropic Cosmic Ray Diffusion
• A Unified Model of the Fermi Bubbles, Microwave Haze, and Polarized Radio Lobes: Reverse Shocks in the Galactic Center's Giant Outflows
• The Galactic Center GeV Excess from a Series of Leptonic Cosmic-Ray Outbursts
• Non-Thermal Insights on Mass and Energy Flows Through the Galactic Centre and into the Fermi Bubbles
• Fermi Bubbles in the Milky Way: the closest AGN feedback laboratory courtesy of Sgr A*?
• The Fermi Bubbles. II. The Potential Roles of Viscosity and Cosmic Ray Diffusion in Jet Models
• The Fermi Bubbles as Starburst Wind Termination Shocks
• The Fermi Bubbles: Gamma-ray, Microwave, and Polarization Signatures of Leptonic AGN Jets
• Unveiling the Origin of the Fermi Bubbles
• A Search for Neutrino Emission from the Fermi Bubbles with the ANTARES Telescope
• Detection Potential of the KM3NeT Detector for High-Energy Neutrinos from the Fermi Bubbles
• Steady-State Hadronic Gamma-Ray Emission from 100-Myr-Old Fermi Bubbles
• Identifying the Radio Bubble Nature of the Microwave Haze
• A novel analytical model of the magnetic field configuration in the Galactic Center
• A Latitude-Dependent Analysis of the Leptonic Hypothesis for the Fermi Bubbles
• IceCube and HAWC constraints on very-high-energy emission from the Fermi bubbles
• Analysis of WMAP 7-year Temperature Data: Astrophysics of the Galactic Haze
• The spectral index of polarized diffuse Galactic emission between 30 and 44 GHz
• Emission from hadronic and leptonic processes in galactic jet-driven bubbles
• On energetics and progenitors of Odd Radio Circles: A causal connection with tidal disruption of stars?
• Testing the dark matter origin of the WMAP-Planck Haze with radio observations of Spiral Galaxies
• QUIJOTE scientific results -- VI. The Haze as seen by QUIJOTE
• Quark Nugget Dark Matter: Comparison with radio observations of nearby galaxies
• Galactic breeze origin for the Fermi bubbles emission
• The AGN Jet Model of the Fermi Bubbles
• Fermi-bubble bulk and edge analysis reveals dust, cooling breaks, and cosmic-ray diffusion, facilitating a self-consistent model
• Detection of polarized Fermi-bubble synchrotron and dust emission
• Fermi Bubbles: an Elephant in the Gamma-ray Sky