A panchromatic spatially resolved study of the inner 500pc of NGC1052 -- II: Gas excitation and kinematics

TL;DR

This study maps the gas excitation and kinematics in the inner 500pc of NGC1052, revealing multiple kinematic components and complex ionization mechanisms involving shocks and photoionization.

Contribution

It provides a detailed spatially resolved analysis of gas dynamics and excitation mechanisms in the central region of NGC1052 using optical and NIR integral field spectroscopy.

Findings

Detection of five distinct kinematic components, including broad, intermediate, and narrow lines.

Identification of complex ionization mechanisms involving shocks and photoionization.

Evidence of bipolar outflows, rotation, and large-scale shocks in the galaxy's core.

Abstract

We map the optical and near-infrared (NIR) emission-line flux distributions and kinematics of the inner 320$\times$535pc$^2$ of the elliptical galaxy NGC1052. The integral field spectra were obtained with the Gemini Telescope using the GMOS-IFU and NIFS instruments, with angular resolutions of 0''88 and 0''1 in the optical and NIR, respectively. We detect five kinematic components: (1 and 2) Two spatially unresolved components, being a broad line region visible in H$\alpha$, with a FWHM of $\sim$3200km s$^{-1}$ and an intermediate-broad component seen in the [OIII]$\lambda \lambda$4959,5007 doublet; (3) an extended intermediate-width component with 280<FWHM<450km s$^{-1}$ and centroid velocities up to 400km s$^{-1}$, which dominates the flux in our data, attributed either to a bipolar outflow related to the jets, rotation in an eccentric disc or a combination of a disc and large-scale gas bubbles; (4 and 5) two narrow (FWHM<150km s$^{-1}$) components, one visible in [OIII], and one visible in the other emission lines, extending beyond the field-of-view of our data, which is attributed to large-scale shocks. Our results suggest that the ionization within the observed field of view cannot be explained by a single mechanism, with photoionization being the dominant mechanism in the nucleus with a combination of shocks and photoionization responsible for the extended ionization.