Image Details
Caption: Figure 1.
Stacked spectrum according to the best-fit normalization (solid black), with 1σ statistical uncertainty (shaded gray) and the 5σ discovery potential (dotted). The energy range of the gray band is computed from the central 68% of events contributing to the total test statistic (TS) values. Model predictions of neutrino spectra for the 14 candidate sources (A. Kheirandish et al. 2021) are shown as well. The 11 subdominant candidates are shown in gray (see Table 1); Centaurus A appears as the highest gray line due to its strong but ambiguous X-ray emission (see Section 2). The Circinus Galaxy (red), NGC 7582 (light pink), and ESO 138-1 (blue) are the candidates with the largest expected number of signal events, excluding Centaurus A.
© 2026. The Author(s). Published by the American Astronomical Society.