Multiwavelength campaign on Mrk 509. II. Analysis of high-quality Reflection Grating Spectrometer spectra

Aims: We study the bright Seyfert 1 galaxy Mrk 509 with the Reflection Grating Spectrometers (RGS) of XMM-Newton, using for the first time the RGS multi-pointing mode of XMM-Newton to constrain the properties of the outflow in this object. We obtain very accurate spectral properties from a 600 ks spectrogram of Mrk 509 with excellent quality.
Methods: We derive an accurate relative calibration for the effective area of the RGS and an accurate absolute wavelength calibration. We improve the method for adding time-dependent spectra and enhance the efficiency of the spectral fitting by two orders of magnitude.
Results: Taking advantage of the spectral data quality when using the new RGS multi-pointing mode of XMM-Newton, we show that the two velocity troughs previously observed in UV spectra are resolved.