Search for Gamma-Ray Emission from the Nova-Like Variable AE Aquarii Using the Fermi-LAT Pass 8 Data Archive

We present the preliminary results of the search for gamma-ray emission from the novalike variable AE Aquarii using the upgraded Fermi-LAT Pass 8 data set.A previous study using the Fermi-LAT Pass 7 data pipeline showed indications of a low-level, but consistent, pulsed emission at a period of 16.54 s, which is the first harmonic of the 33.08 s spin period of the white dwarf.Here we report our findings of a follow-up study utilizing the Pass 8 data, which uses an improved galactic diffuse gamma-ray emission model as well as more inclusive selection criteria.Thus far no clear detection of any significant gamma-ray excess from AE Aqr in the Fermi-LAT energy range has been made.However, there are some energy bins with significance just above 2σ .This significance value is below the Fermi-LAT detection limit that signifies a clear 4-5 σ detection and can only be considered as a 2 σ upper-limit.The corresponding upper limit of the integrated energy flux above 100 MeV is F γ ∼ 4×10 -13 erg cm -2 s -1 which is determined at the 99.995 % confidence level.However, indications of low-level pulsed modulation is found at, or close to, the 33.08 s spin period of the white dwarf in a few two-week data sections with higher than average TS values, which is promising for possible future follow-up studies with the Cherenkov Telescope Array.