Is HE 0436-4717 Anemic? A deep look at a bare Seyfert 1 galaxy

TL;DR

This study analyzes the X-ray and optical properties of the bare Seyfert 1 galaxy HE 0436-4717, finding that blurred reflection best explains its spectral features and suggesting a very low iron abundance.

Contribution

It provides a comprehensive multi-epoch analysis of HE 0436-4717, comparing three models and identifying blurred reflection as the most consistent explanation for its X-ray spectra.

Findings

HE 0436-4717 shows negligible line-of-sight absorption.

Blurred reflection model best fits the data, especially with rapid variability.

The galaxy may have an intrinsically low iron abundance.

Abstract

A multi-epoch, multi-instrument analysis of the Seyfert 1 galaxy HE 0436-4717 is conducted using optical to X-ray data from XMM-Newton and Swift (including the BAT). Fitting of the UV-to-X-ray spectral energy distribution shows little evidence of extinction and the X-ray spectral analysis does not confirm previous reports of deep absorption edges from OVIII. HE 0436-4717 is a "bare" Seyfert with negligible line-of-sight absorption making it ideal to study the central X-ray emitting region. Three scenarios were considered to describe the X-ray data: partial covering absorption, blurred reflection, and soft Comptonization. All three interpretations describe the 0.5-10.0 keV spectra well. Extrapolating the models to 100 keV results in poorer fits for the the partial covering model. When also considering the rapid variability during one of the XMM-Newton observations, the blurred reflection model appears to describe all the observations in the most self-consistent manner. If adopted, the blurred reflection model requires a very low iron abundance in HE 0436-4717. We consider the possibilities that this is an artifact of the fitting process, but it appears possible that it is intrinsic to the object.