Chandra LETGS and XMM-Newton observations of NGC 4593
Kaastra, J. S.; Behar, E.; Sako, M.; Branduardi-Raymont, G.; Steenbrugge, K. C.; Walter, R.; Kahn, S. M.; Paerels, F. B. S.; Blustin, A. J.
Netherlands, United Kingdom, United States, Israel, Switzerland
Abstract
In this paper, we analyze spectra of the Seyfert 1 galaxy NGC 4593 obtained with the Chandra Low Energy Transmission Grating Spectrometer (LETGS), the Reflection Grating Spectrometer (RGS) and the European Photon Imaging Camera's (EPIC) onboard of XMM-Newton. The two observations were separated by ~ 7 months. In the LETGS spectrum we detect a highly ionized warm absorber corresponding to an ionization state of 400*E-9 W m, visible as a depression at 10-18 Å. This depression is formed by multiple weak Fe and Ne lines. A much smaller column density was found for the lowly ionized warm absorber, corresponding to xi = 3 *E-9 W m. However, an intermediate ionization warm absorber is not detected. For the RGS data the ionization state is hard to constrain. The EPIC results show a narrow Fe Kalpha line.