XMM Observations of the Seyfert 2 Galaxy NGC 7590: the Nature of X-ray Absorption

TL;DR

This study uses XMM observations to analyze the X-ray properties of NGC 7590, revealing it is likely Compton-thick with a weak nucleus, dominated by off-nuclear sources, challenging previous assumptions of it being unobscured.

Contribution

First detailed X-ray analysis with high spatial resolution showing NGC 7590 is probably Compton-thick, not an unobscured Seyfert 2 galaxy.

Findings

X-ray emission dominated by off-nuclear ULX and extended host galaxy emission

Nuclear X-ray luminosity is very low

NGC 7590 is likely Compton-thick rather than unobscured

Abstract

We present the analysis of three XMM observations of the Seyfert 2 galaxy NGC 7590. The source was found to have no X-ray absorption in the low spatial resolution ASCA data. The XMM observations provide a factor of 10 better spatial resolution than previous ASCA data. We find that the X-ray emission of NGC 7590 is dominated by an off-nuclear ULX and extended emission from the host galaxy. The nuclear X-ray emission is rather weak comparing with the host galaxy. Based on its very low X-ray luminosity as well as the small ratio between the 2-10 keV and the [O III] fluxes, we interpret NGC 7590 as Compton-thick rather than being an "unobscured" Seyfert 2 galaxy. Future higher resolution observations such as Chandra are crucial to shed light on the nature of NGC 7590 nucleus.