XMM-Newton spectrum of the magnetar CXOU J171405.7-381031

We observe the magnetar CXOU J171405.7-381031 with XMM-Newton and obtain the most reliable X-ray spectral parameters for this magnetar. After removing the flux from the surrounding supernova remnant CTB 37B, the radiation of CXOU J171405.7-381031 is best described by a two-component model, consisting of a blackbody and power law. We obtain a blackbody temperature of 0.58^{+0.03}_{-0.03} keV, a photon index of 2.15^{+0.62}_{-0.68}, and an unabsorbed 2-10 keV band flux of 2.33^{+0.02}_{-0.02} × 10^{-12} erg cm^-2 s^-1. These new parameters enable us to compare CXOU J171405.7-381031 with other magnetars, and it is found that the luminosity, temperature, and photon index of CXOU J171405.7-381031 are aligned with the known trend among the magnetar population with a slightly higher temperature, which could be caused by its young age. All magnetars with a spin-down age of less than 1000 yr show time variation or bursts except for CXOU J171405.7-381031. We explore the time variability for six observations between 2006 and 2015, but there is no variation larger than ∼10%.