Spatially Extended NaI D Resonant Emission and Absorption in the Galactic Wind of the Nearby Infrared-Luminous Quasar F05189-2524

TL;DR

This study presents the first 3D spatially resolved NaI D emission observations of a galactic wind in a nearby infrared-luminous quasar, providing new insights into the structure and properties of cool gas in such winds.

Contribution

It provides the second spatially resolved NaI D emission observation in a galactic wind and the first 3D observation at any redshift, offering new constraints for models of cool gas in galactic winds.

Findings

NaI D emission traces extended galactic wind structures up to 4 kpc.

NaI D absorption reveals dusty filaments with velocities up to 2000 km/s.

NaI D emission correlates with regions of low foreground obscuration.

Abstract

Emission from metal resonant lines has recently emerged as a potentially powerful probe of the structure of galactic winds at low and high redshift. In this work, we present only the second example of spatially resolved observations of NaI D emission from a galactic wind in a nearby galaxy (and the first 3D observations at any redshift). F05189-2524, a nearby (z=0.043) ultra luminous infrared galaxy powered by a quasar, was observed with the integral field unit on the Gemini Multi-Object Spectrograph (GMOS) at Gemini North. NaI D absorption in the system traces dusty filaments on the near side of an extended, AGN-driven galactic wind (with projected velocities up to 2000 km/s). These filaments (A_V < 4) and N(H) < 10^22 cm^-2) simultaneously obscure the stellar continuum and NaI D emission lines. The NaI D emission lines serve as a complementary probe of the wind; they are strongest in regions of low foreground obscuration and extend up to the limits of the field of view (galactocentric radii of 4 kpc). An azimuthally symmetric Sersic model extincted by the same foreground screen as the stellar continuum reproduces the NaI D emission line surface brightness distribution except in the inner regions of the wind, where some emission-line filling of absorption lines may occur. The presence of detectable NaI D emission in F05189-2524 may be due to its high continuum surface brightness at the rest wavelength of NaI D. These data uniquely constrain current models of cool gas in galactic winds and serve as a benchmark for future observations and models.