The NuSTAR View of the Seyfert 2 Galaxy NGC 4388

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${}_H=(6.5\pm 0.8)\times 10^{23}$ cm${}^{-2}$) with a very weak Compton reflection hump (R $<$ 0.09) and an exceptionally large Fe K$\alpha$ line (EW $=368_{-53}^{+56}$ 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.

arXiv comment5 pages, 2 figures. Accepted for publication in ApJ

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Cited by in corpus (3)

• The kpc Scale Fe K$\alpha$ Emission in the Compton Thin Seyfert 2 Galaxy NGC 4388 resolved by Chandra
• A NICER Look at Strong X-ray Obscuration in the Seyfert-2 Galaxy NGC 4388
• The coronal temperature of NGC 4388 and NGC 2110 measured with INTEGRAL