2025/06/17 by Falcão, Anna Trindade, Fabbiano, G., Elvis, M. +5 · 2 citations
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2506.14931
We present a spatially resolved Baldwin-Phillips-Terlevich analysis of the narrow-line region (NLR) in the low-ionization nuclear emission-line region (LINER) I galaxy NGC 5005 using Hubble Space Telescope narrowband imaging of [O III]λ5007, Hβ, Hα, and [S II]λλ6717,6731. With a resolution of \lesssim0.1 (\lesssim10 pc at z = 0.003), we dissect the NLR into H II (star-forming), Seyfert, and LINERs across spatial scales extending up to r∼8 kpc from the nucleus. Our results reveal a compact nuclear region exhibiting Seyfert-like emission, consistent with photoionization by a low-luminosity active galactic nucleus (AGN). Surrounding this Seyfert-like nucleus is a thin (∼20 pc thick) higher-excitation LINER-like cocoon, likely arising from shock-excited gas in the interstellar medium (ISM). Beyond this cocoon, a centrally localized extended (r∼1 kpc) LINER-like region surrounds the Seyfert-like nucleus and cocoon, likely ionized by the AGN, while a more extended (r\gtrsim2 kpc) LINER-like zone may be ionized by a combination of post-AGB stars and shocks from gas inflows. We also detect H II-like regions at both small and large scales. In the inner 500 pc, these regions may be triggered by jet-ISM interactions, potentially inducing localized star formation. At r∼4 kpc, we identify an outer H II-like region tracing a large-scale star-forming ring, where ionization is dominated by young stars.