EXPLORING THE X-RAY AND γ -RAY PROPERTIES OF THE REDBACK MILLISECOND PULSAR PSR J1723−2837

We have investigated the X-ray and γ-ray properties of the redback millisecond pulsar PSR J1723–2837 with XMM-Newton, Chandra, and Fermi. We have discovered the X-ray orbital modulation of this binary system with a minimum that coincides with the phases of radio eclipse. The X-ray emission is clearly non-thermal in nature, which can be described well by a simple power law with a photon index of ~1.2. The phase-averaged luminosity is ~9 × 1031 erg s–1 in 0.3-10 keV, which consumes ~0.2% of the spin-down power. We have detected the γ-ray emission in 0.1-300 GeV from this system at a significance of ~6σ for the first time. The γ-rays in this energy range consume ~2% of the spin-down power and can be modeled by a power law with a photon index of ~2.6. We discuss the high energy properties of the new redback in the context of an intrabinary shock model.