# HI gas in the rejuvenated radio galaxy PKS 2014-55

## TL;DR

This study uses high-resolution MeerKAT observations to analyze HI absorption in the rejuvenated radio galaxy PKS2014-55, revealing complex gas kinematics and supporting a link between HI presence and renewed radio activity.

## Contribution

First detailed HI absorption study of PKS2014-55 showing multiple velocity components and complex gas dynamics related to radio galaxy rejuvenation.

## Key findings

- Detection of three HI absorption components with distinct velocities.
- Evidence of gas kinematics exceeding typical rotational speeds.
- Support for the link between HI absorption and radio activity rejuvenation.

## Abstract

We present new high-spectral-resolution MeerKAT observations of $\mathrm{HI}$ absorption against the central region of the restarted, giant, X-shaped radio galaxy PKS2014-55, which exhibits morphological evidence of three distinct cycles of activity. We report a wide component $(\mathrm{FWHM}=38 \pm 7~\mathrm{kms^{-1}})$ redshifted to $96 \pm 50~\mathrm{kms^{-1}}$, a deep narrow detection $(\mathrm{FWHM}=19 \pm 6~\mathrm{kms^{-1}})$ redshifted to $160 \pm 40~\mathrm{kms^{-1}}$, and a shallow component $(\mathrm{FWHM}=22 \pm 6~\mathrm{kms^{-1}})$ redshifted to $240 \pm 40~\mathrm{kms^{-1}}$. One of the three components exceeds the typical rotational velocity of $100~\mathrm{kms^{-1}}$, suggesting complex kinematics of the inflowing gas. These $\mathrm{HI}$ observations support the correlation between the occurrence of $\mathrm{HI}$ absorption and the rejuvenation of radio activity.