Free Access
Volume 523, November-December 2010
Article Number L2
Number of page(s) 7
Section Letters
DOI https://doi.org/10.1051/0004-6361/201015759
Published online 10 November 2010

Online material

Appendix A: Gamma-ray spectrum of M 31

Table A.1 provides the intensity values of the M 31 gamma-ray spectrum that is shown in Fig. 2. Statistical errors are at the 1σ confidence level, and the upper limit for the 16.6–50.0 GeV energy bin at the 2σ confidence level. Systematic errors include uncertainties in our knowledge of the effective area of the LAT and uncertainties in the modelling of diffuse Galactic gamma-ray emission. The former were determined using modifications of the instrument response functions that bracket the uncertainties in our knowledge of the LAT effective area. The latter were determined by deriving spectra for variations of the diffuse Galactic models that make use of either an E(BV) template or for which the gas templates have been replaced by the IRIS 100 μm map, from which emission associated to M 31 has been removed. Both types of systematic uncertainties were added linearily.

The last column gives the number of counts attributed to M 31 in each of the energy bins from the fit of a spatial model to the present data.

Table A.1

Measured spectrum of M 31 (see text).

© ESO, 2010

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.