The quasar PG 0844+349 in an X-ray weak state

TL;DR

This study analyzes the long-term spectral and timing variability of quasar PG 0844+349 over ten years, revealing a reflection-dominated state during X-ray weakness possibly due to light bending effects.

Contribution

It provides a comprehensive comparison of partial covering and blurred reflection models across multiple flux states, highlighting the role of light bending in X-ray weak phases.

Findings

PG 0844+349 was in a reflection-dominated state during X-ray weakness.

Light bending can explain both the spectral state and short-term variability.

Models other than blurred reflection are less favored but not ruled out.

Abstract

In March 2009 the well-studied quasar, PG 0844+349, was discovered with Swift to be in an X-ray weak state. A follow-up XMM-Newton observation several weeks later generated a good quality spectrum of the source, showing substantial curvature and spectral hardening. In combination with archival data at two previous epochs when the source was in a bright state, we examine the long-term spectral and timing properties of PG 0844+349 spanning nearly ten years and a factor of ten in brightness. Partial covering and blurred reflection models are compared to the data at each flux state while attempting to maintain consistency between the various epochs. In terms of the blurred reflection model, PG 0844+349 is in a reflection dominated state during the 2009 X-ray weak observations, which can be understood in terms of light bending. Moreover, the light bending scenario can also account for the short-term (i.e. ~1000s) spectral variability in the source. Other models cannot be decisively ruled out, but we note distinguishing features of the models that can be explored for in higher signal-to-noise data from current and future observatories.