NIR imaging spectroscopy of the inner few arcseconds of NGC 4151 with OSIRIS at Keck

TL;DR

This study uses adaptive optics NIR spectroscopy to analyze the inner region of NGC 4151, revealing detailed morphology and dynamics of its narrow line region, plasma interactions, and nuclear absorption features.

Contribution

First detailed adaptive optics NIR spectroscopic analysis of NGC 4151's inner arcsecond focusing on morphology and plasma dynamics.

Findings

Mapped the morphology of [FeII] emission and hot H2 gas.

Characterized nuclear HeI absorption as a narrow absorption line.

Revealed interplay between nuclear plasma and surrounding gas.

Abstract

We present H- and K-band data from the inner arcsecond of the Seyfert 1.5 galaxy NGC 4151 obtained with the adaptive optics assisted near-infrared imaging field spectrograph OSIRIS at the Keck Observatory. We present the morphology and dynamics of most species detected but focus on the morphology and dynamics of the narrow line region (as traced by emission of [FeII] \lambda 1.644\mu m), the interplay between plasma ejected from the nucleus (as traced by 21 cm continuum radio data) and hot H2 gas and characterize the detected nuclear HeI$\lambda 2.058 \mu m absorption feature as a narrow absorption line (NAL) phenomenon.