CONICET | Buscador de Institutos y Recursos Humanos

We study the temporal and spectral characteristics of the X-ray emission of the hard X-ray transient binary system IGR~J17503--2636 to characterize its variability and spectral properties. This source was observed by XMM-Newton on April 3, 2020 with an exposure time of ${sim}27~mathrm{ks}$. The light curves show variability on several timescales, from short (few dozen seconds) to long flares (on the order of kiloseconds), with no significant variability in hardness.We successfully modeled the average EPIC spectrum using a combination of black-body and power-law emission both affected by interstellar and local absorption. We obtained an absorption column of $N_{ m H}{sim}13 imes 10^{22}~mathrm{cm}^{-2}$, with an spectral index of $Gamma{sim}0.3$ and temperature of $kT{sim}1.3~mathrm{keV}$. We find no evidence of iron line emission at ${sim}6~mathrm{keV}$. The unabsorbed luminosity in the 0.5--10$~mathrm{keV}$ energy range of the source is estimated to be ${sim}5.7 imes 10^{35}~mathrm{erg,s}^{-1}$ assuming a distance of $10~mathrm{kpc}$. In summary, IGR~J17503--2636 behaves as a typical highly absorbed transient X-ray binary system.