July 29, 2015 to August 6, 2015
World Forum
Europe/Amsterdam timezone

Fermi-LAT observations of the Sagittarius B complex

Aug 4, 2015, 3:45 PM
Yangtze 2 (World Forum)

Yangtze 2

World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Poster contribution CR-TH Parallel CR18 TH prop


Yang Ruizhi


We use 5 years of Fermi-LAT data towards the Galactic centre giant molecular cloud complex, Sagittarius B, to test questions of how well-mixed the Galactic component of cosmic rays are and the level of the cosmic-ray sea in different parts of the Galaxy. We use dust-opacity maps from the Planck satellite to obtain independent methods for background subtraction, and an estimate for the mass of the region. We then present high-quality spectrum of γ-ray emission from 0.3 to 30 GeV, and obtain an estimate of the cosmic-ray spectrum from the region. We obtain an estimate of the mass of the region of 1.5 ± 0.2 × 107 M⊙ using the Planck data, which agrees well with molecular-line derived estimates for the same region. We find the the γ-ray flux from this region is well-fit with a cosmic-ray spectrum the same as that observed locally, with evidence of a small over-density at intermediate (1–10 GeV) energies. We conclude that the γ-ray and cosmic-ray spectrum in the region can be well-fit using a local cosmic-ray spectrum.
Collaboration -- not specified --
Registration number following "ICRC2015-I/" 92

Primary author


Dr David Jones (Department of Astrophysics/IMAPP, Radboud University) Prof. Felix Aharonian (Max-Planck-Institut für Kernphysik)

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