Multiwavelength campaign on Mrk 509. III. The 600 ks RGS spectrum: unravelling the inner region of an AGN

TL;DR

This study analyzes a 600 ks high-resolution X-ray spectrum of Mrk 509, revealing detailed properties of its ionized outflow, emission lines, and ionization structure, providing new insights into the AGN's inner region.

Contribution

It presents the first demonstration that the ionized outflow in Mrk 509 consists of discrete ionization components rather than a smooth distribution, based on high-quality spectral data.

Findings

Ionized outflow has two velocity components at -13 km/s and -319 km/s.

Outflow shows four orders of magnitude in ionization parameter.

Ionization structure features two strong, discrete peaks.

Abstract

We present the results of our 600 ks RGS observation as part of the multiwavelength campaign on Mrk 509. The very high quality of the spectrum allows us to investigate the ionized outflow with an unprecedented accuracy due to the long exposure and the use of the RGS multipointing mode. We detect multiple absorption lines from the interstellar medium and from the ionized absorber in Mrk 509. A number of emission components are also detected, including broad emission lines consistent with an origin in the broad line region, the narrow OVII forbidden emission line and also (narrow) radiative recombination continua. The ionized absorber consists of two velocity components (v = -13 \pm 11 km/s and v = -319 \pm 14 km/s), which both are consistent with earlier results, including UV data. There is another tentative component outflowing at high velocity, -770 \pm 109 km/s, which is only seen in a few highly ionized absorption lines. The outflow shows discrete ionization components, spanning four orders of magnitude in ionization parameter. Due to the excellent statistics of our spectrum, we demonstrate for the first time that the outflow in Mrk 509 in the important range of log xi between 1-3 cannot be described by a smooth, continuous absorption measure distribution, but instead shows two strong, discrete peaks. At the highest and lowest ionization parameters we cannot differentiate smooth and discrete components.