ReveaLLAGN 0: First Look at JWST MIRI data of Sombrero and NGC 1052

TL;DR

This study uses JWST MIRI data to analyze low-luminosity AGN in NGC 1052 and Sombrero, revealing their spectral features, outflows, and comparing them to higher-luminosity AGN, demonstrating JWST's potential for LLAGN research.

Contribution

First JWST MIRI observations of LLAGN NGC 1052 and Sombrero, providing new insights into their spectral properties and outflows compared to higher-luminosity AGN.

Findings

JWST separates AGN spectra from galaxy light even in faint targets

Emission-line widths increase with ionization potential, indicating outflows

Sombrero shows the lowest luminosity high-ionization lines ever measured in mid-IR

Abstract

We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGN. We focus on two observations with the Mid-Infrared Instrument's (MIRI) Medium Resolution Spectrograph (MRS) of the nuclei of NGC 1052 and Sombrero (NGC 4594 / M104). We also compare these data to public JWST data of a higher-luminosity AGN, NGC 7319 and NGC 7469. JWST clearly separates the AGN spectrum from the galaxy light even in Sombrero, the faintest target in our survey; the AGN components have very red spectra. We find that the emission-line widths in both NGC 1052 and Sombrero increase with increasing ionization potential, with FWHM > 1000 km/s for lines with ionization potential > 50 eV. These lines are also significantly blue-shifted in both LLAGN. The high ionization potential lines in NGC 7319 show neither broad widths or significant blue shifts. Many of the lower ionization potential emission lines in Sombrero show significant blue wings extending > 1000 km/s. These features and the emission-line maps in both galaxies are consistent with outflows along the jet direction. Sombrero has the lowest luminosity high-ionization potential lines ([Ne V] and [O IV]) ever measured in the mid-IR, but the relative strengths of these lines are consistent with higher luminosity AGN. On the other hand, the [Ne V] emission is much weaker relative to the [Ne III] and [Ne II] lines of higher-luminosity AGN. These initial results show the great promise that JWST holds for identifying and studying the physical nature of LLAGN.