# Swift, NuStar and XMM-Newton observations of the NLS1 galaxy RX J2317.8-4422 in an extreme X-ray low flux state

## TL;DR

This paper reports the discovery of an extreme X-ray flux drop in the NLS1 galaxy RX J2317.8-4422, with multi-wavelength follow-up revealing significant variability and exploring potential causes like accretion rate changes or absorption.

## Contribution

The study provides detailed multi-epoch observations of RX J2317.8-4422's extreme X-ray variability, offering insights into its spectral states and potential physical mechanisms.

## Key findings

- X-ray flux dropped by a factor of 100 in 2014
- Spectral modeling suggests partial covering absorption or blurred reflection
- Long-term variability possibly due to accretion rate changes or absorption

## Abstract

We report the discovery of RX J2317.8-4422 in an extremely low X-ray flux state by the Neil Gehrels Swift observatory in 2014 April/May. In total, the low-energy X-ray emission dropped by a factor 100. We have carried out multi-wavelength follow-up observations of this Narrow-Line Seyfert 1 galaxy. Here we present observations with Swift, XMM-Newton, and NuSTAR in October and November 2014 and further monitoring observations by Swift from 2015 to 2018. Compared with the beginning of the Swift observations in 2005, in the November 2014 XMM and NuSTAR observation RX J2317--4422.8 dropped by a factor of about 80 in the 0.3-10 keV band. While the high-state Swift observations can be interpreted by a partial covering absorption model with a moderate absorption column density of $N_H=5.4\times 10^{22}$ cm$^{-2}$ or blurred reflection, due to dominating background at energies above 2 keV the low-state XMM data can not distinguish between different multi-component models and were adequately fit with a single power-law model. We discuss various scenarios like a long-term change of the accretion rate or absorption as the cause for the strong variability seen in RX J2317.8--4422.