Results form the long-term Fermi-LAT observations of the white dwarf binary pulsar AR Scorpii
July 22, 2019
July 02, 2021
The discovery of the white dwarf binary system AR Scorpii (AR Sco) with its fascinating non-thermal dominated multi-frequency emission has sparked renewed interest in potential high energy gamma-ray emission from white dwarf pulsars. The Spectral Energy Distribution (SED) below and above optical shows evidence of non-thermal synchrotron emission, with pulsed emission in optical and X-ray bands at the white dwarf spin period (P ∗ = 117 s) as well as a beat
period (P b = 118.1 s) with the binary period. From an energy perspective, the highly magnetic rotating white dwarf can accelerate particles to TeV energies. In this study, a search for high
energy gamma-ray emission was conducted between 100 MeV - 500 GeV by analysing the newly available Fermi-LAT Pass 8 data with the new Fermi 1.0.1 Science Tools. Binned likelihood anal-
ysis was done using power law, broken power law and log parabola models. From the selected Region of Interest (ROI) centred on AR Sco’s position, we calculated a significance of T S ≤ 3.87σ for the integrated gamma-ray activity between 100 MeV - 500 GeV at a photon flux level of 0.486 ± 0.261 x 10^−8 photons cm^−2 s^−1 using the broken power law model. This resulted in a 3σ upper-limit detection from the position of AR Sco. The location of AR Sco inside the
Rho Ophiuchi (Rho Oph) molecular cloud complex combined with the poor spatial resolution of Fermi-LAT, complicates any positive identification of low-level gamma-ray activity at the loca-
tion that coincides with the position of AR Sco.
How to cite
Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating
very compact bibliographies which can be beneficial to authors and
readers, and in "proceeding" format
which is more detailed and complete.