The sky distribution of 511 keV positron annihilation line emission as measured with INTEGRAL/SPI

Abstract

The imaging spectrometer SPI on board ESA's INTEGRAL observatory provides us with an unprecedented view of positron annihilation in our Galaxy. The first sky maps in the 511 keV annihilation line and in the positronium continuum from SPI showed a puzzling concentration of annihilation radiation in the Galactic bulge region. By now, more than twice as many INTEGRAL observations are available, offering new clues to the origin of Galactic positrons. We present the current status of our analyses of this augmented data set. We now detect significant emission from outside the Galactic bulge region. The 511 keV line is clearly detected from the Galactic disk; in addition, there is a tantalizing hint at possible halo-like emission. The available data do not yet permit to discern whether the emission around the bulge region originates from a halo-like component or from a disk component that is very extended in latitude.

arXiv commentto be published in the proceedings of the 6th INTEGRAL Workshop "The Obscured Universe" (3-7 July 2006, Moscow)

Cited by in corpus (8)

• Consistent Scenarios for Cosmic-Ray Excesses from Sommerfeld-Enhanced Dark Matter Annihilation
• Interacting dark matter contribution to the Galactic 511 keV gamma ray emission: constraining the morphology with INTEGRAL/SPI observations
• Decaying into the Hidden Sector
• Updated Constraints on Primordial Black Hole Evaporation
• ATIC and PAMELA Results on Cosmic e^\pm Excesses and Neutrino Masses
• Exciting dark matter in the galactic center
• 511 keV Line Emission from Nearby Spherical Dwarf Galaxies
• The dark connection between the EGRET excess of diffuse Galactic gamma rays, the Canis Major dwarf, the Monoceros ring, the INTEGRAL 511 keV annihilation line, the gas flaring and the Galactic rotation curve