The multi-epoch X-ray tale of I Zwicky 1 outflows

Abstract

The narrow-line Seyfert 1 galaxy I Zwicky 1 shows a unique and complex system of ionised gas in outflow, which consists of an ultra-fast wind and a two-component warm absorber. In the last two decades, XMM-Newton monitored the source multiple times enabling the study of the long-term variability of the various outflows. Plasma in photoionisation equilibrium with the ionising source responds and varies accordingly to any change of the ionising luminosity. However, detailed modelling of the past RGS data has shown no correlation between the plasma ionisation state and the ionising continuum, revealing a complex long-term variability of the multi-phase warm absorber. Here, we present a new observation of I Zwicky 1 by XMM-Newton taken in early 2020 characterised by a lower X-ray flux state. The soft X-ray spectrum from the RGS reveals the two components of the warm absorber with $\log \xi \sim -1.0$ and $\log \xi \sim 1.7$. Comparing our results with the previous observations, the ionisation state of the two absorbing gas components is continuously changing, following the same unpredictable behaviour. The new results strengthen the scenario in which the ionisation state of the warm absorber is driven by the density of the gas rather than the ionising luminosity. In particular, the presence of a radiation driven, inhomogeneous clumpy outflow may explain both the variability in ionisation throughout the years and the line-locked N V system observed in the UV band. Finally, the EPIC-pn spectrum reveals an ultra-fast wind with an outflow velocity of $\sim 0.26c$ and ionisation parameter of $\log \xi \sim 3.8$.

16 pages, 11 figures, 3 tables, accepted for publication in MNRAS

References in corpus (12)

• A fast and long-lived outflow from the supermassive black hole in NGC 5548
• Systematic comparison of photoionised plasma codes with application to spectroscopic studies of AGN in X-rays
• The soft X-ray excess: NLS1s vs. BLS1s
• Timing the warm absorber in NGC 4051
• Light bending and X-ray echoes from behind a supermassive black hole
• Revealing structure and evolution within the corona of the Seyfert galaxy I Zw 1
• Line-driven radiative outflows in luminous quasars
• Reverberation mapping of narrow-line Seyfert 1 galaxy I Zwicky 1: black hole mass
• A longer XMM-Newton look at I Zwicky 1: Variability of the X-ray continuum, absorption, and iron Kalpha line
• A longer XMM-Newton look at I Zwicky 1: physical conditions and variability of the ionised absorbers
• Acceleration and cooling of the corona during X-ray flares from the Seyfert galaxy I Zw 1
• The hot interstellar medium towards 4U 1820-30: a Bayesian analysis

Cited by in corpus (4)

• A systematic study of the ultra-fast outflow responses to luminosity variations in active galactic nuclei
• I Zw 1 and H0557-385: The Dusty Tori of Two High Eddington AGNs Observed in the MATISSE LM-Bands
• The Reliability of Accretion Disk Inclination Derived from X-ray Spectroscopy of Active Galaxies
• Strong X-ray Variability of I Zwicky 1: Obscuration from Clumpy Accretion-Disk Winds