HI gas in the rejuvenated radio galaxy PKS 2014-55

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 $(\mathrm{FWHM}=38\pm 7\mathrm{km}{\mathrm{s}}^{-1})$ redshifted to $96\pm 50\mathrm{km}{\mathrm{s}}^{-1}$, a deep narrow detection $(\mathrm{FWHM}=19\pm 6\mathrm{km}{\mathrm{s}}^{-1})$ redshifted to $160\pm 40\mathrm{km}{\mathrm{s}}^{-1}$, and a shallow component $(\mathrm{FWHM}=22\pm 6\mathrm{km}{\mathrm{s}}^{-1})$ redshifted to $240\pm 40\mathrm{km}{\mathrm{s}}^{-1}$. One of the three components exceeds the typical rotational velocity of $100\mathrm{km}{\mathrm{s}}^{-1}$, 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.