Spatial extension of dark subhalos as seen by Fermi-LAT and the implications for WIMP constraints
Spatial extension has been hailed as a “smoking gun” in the gamma-ray search of dark galactic subhalos, which would appear as unidentified sources for gamma-ray telescopes. In this work, we study the sensitivity of the Fermi-LAT to extended subhalos using simulated data based on a realistic sky model. We simulate spatial templates for a set of representative subhalos, whose parameters were derived from our previous work with N-body cosmological simulation data. We find that detecting an extended subhalo and finding an unequivocal signal of angular extension requires, respectively, a flux 2 to 10 times larger than in the case of a pointlike source. By studying a large grid of models, where parameters such as the WIMP mass, annihilation channel, or subhalo model are varied significantly, we obtain the response of the LAT as a function of the product of annihilation cross-section times the J-factor. Indeed, we show that spatial extension can be used as an additional “filter” to reject subhalos candidates among the pool of unidentified LAT sources, as well as a smoking gun for positive identification. For instance, typical angular extensions of a few tenths of a degree are expected for the considered scenarios. Finally, we also study the impact of the obtained LAT sensitivity to such extended subhalos on the achievable dark matter constraints, which are a few times less constraining than comparable point-source limits.
2022
2023-01-26 16:53:37
1033
dark matter, cosmic rays and astroparticles, gamma-ray astronomy, particle astrophysics, particle dark matter
r6
Javier
Coronado-Blázquez
70
Miguel
Sánchez-Conde
70
Judit
Pérez Romero
70
Alejandra
Aguirre-Santaella
70
COBISS_ID
3
139643907
DOI
15
10.1103/PhysRevD.105.083006
NUK URN
18
URN:SI:UNG:REP:SEYAJJTK
PhysRevD.105.083006.pdf
4749023
Predstavitvena datoteka
2023-01-26 16:53:59
0
Izvorni URL
2023-01-26 16:53:51