# The NuSTAR View of the Seyfert 2 Galaxy NGC 4388

## TL;DR

This paper analyzes NuSTAR X-ray observations of the Seyfert 2 galaxy NGC 4388, revealing a moderately absorbed spectrum with weak reflection and a strong Fe Kα line, providing insights into the circumnuclear material's geometry.

## Contribution

First detailed broadband X-ray spectral analysis of NGC 4388 using NuSTAR data, constraining reflection features and circumnuclear material properties.

## Key findings

- NGC 4388 is absorbed by Compton-thin material with N_H ≈ 6.5×10^23 cm^-2.
- The source exhibits a very weak Compton reflection hump (R < 0.09).
- An exceptionally large Fe Kα line EW suggests emission from Compton-thin material.

## Abstract

We present analysis of NuSTAR X-ray observations in the 3-79 keV energy band of the Seyfert 2 galaxy NGC 4388, taken in 2013. The broadband sensitivity of NuSTAR, covering the Fe K$\alpha$ line and Compton reflection hump, enables tight constraints to be placed on reflection features in AGN X-ray spectra, thereby providing insight into the geometry of the circumnuclear material. In this observation, we found the X-ray spectrum of NGC 4388 to be well described by a moderately absorbed power law with non-relativistic reflection. We fit the spectrum with phenomenological reflection models and a physical torus model, and find the source to be absorbed by Compton-thin material (N$_{H} = (6.5\pm0.8)\times10^{23}$ cm$^{-2}$) with a very weak Compton reflection hump (R $<$ 0.09) and an exceptionally large Fe K$\alpha$ line (EW $= 368^{+56}_{-53}$ eV) for a source with weak or no reflection. Calculations using a thin-shell approximation for the expected Fe K$\alpha$ EW indicate that an Fe K$\alpha$ line originating from Compton-thin material presents a possible explanation.