Morphology of the dark matter contribution to the 511 keV gamma ray sky:
constraints from INTEGRAL/SPI observations
Aaron Vincent
McGill University
Observations from the past 40 years show a clear, unambiguous detection
of a 511 keV gamma-ray line originating in a spherically-symmetric region
around the centre of the Milky Way, in addition to a fainter, disk-like
component extending along the galactic plane. This implies the annihilation
- and thus, the creation - of 1.5 x 10^43 electron-positron pairs every
second. Known astrophysical positron sources mainly predict a bulge-to-disk
(B/D) luminosity < 0.5, far below the B/D > 1.4 required by the most
recent observations from the INTEGRAL/SPI space-borne experiment. I
will introduce the 511 keV anomaly, and present a brief review of these
sources. I will then show that interacting dark matter (DM) is an ideal
candidate source which can produce the correct spectrum and morphology with
minimal assumptions about the DM model. Indeed, DM can give a fit to the
INTEGRAL/SPI data that is as good as the best phenomenological fits, but
with six fewer degrees of freedom, when data from many-body DM simulations
and gamma-ray observations of radioactive isotopes are included.
Date: | Mercredi, le 8 février 2012 |
Heure: | 14:30 |
Lieu: | Université McGill |
| Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103) |
Contact: | Robert Rutledge |
|