Location and energetics of the ultra-fast outflow in PG 1448+273

TL;DR

This study characterizes the ultra-fast outflow in galaxy PG 1448+273 using novel spectral modeling, revealing its high velocity, ionization, energetics, and potential impact on the galaxy's accretion processes.

Contribution

The paper introduces the WINE modeling tool to accurately determine the location and energetics of UFOs, providing new insights into their properties and effects in AGN.

Findings

UFO detected with high ionization and velocity

WINE constrains the launching radius and covering factor

Significant outflow kinetic power and variability in X-ray emission

Abstract

Ultra-fast outflows (UFOs) play a key role in the AGN feedback mechanism. It is therefore important to fully characterize their location and energetics. We study the UFO in the latest XMM-Newton archival observation of the NLSy1 galaxy PG 1448+273 by means of a novel modeling tool, that is, the Wind in the Ionized Nuclear Environment model (WINE). Our detection of the UFO in PG 1448+273 is very robust. The outflowing material is highly ionized, $\log\xi = 5.53_{-0.05}^{+0.04}$ erg s$^{-1}$ cm, has a large column density, $N_\mathrm{H} = 4.5_{-1.1}^{+0.8} \times 10^{23}$ cm$^{-2}$, is ejected with a maximum velocity $v_0 = 0.24^{+0.08}_{-0.06}\,c$ (90% c.l. errors), and attains an average velocity $v_\mathrm{avg} = 0.152\,c$. WINE succeeds remarkably well to constrain a launching radius of $r_0=77_{-19}^{+31} \, r_\mathrm{S}$ from the black hole. We also derive a lower limit on both the opening angle of the wind ($\theta > 72^{\circ}$) and the covering factor ($C_\mathrm{f} > 0.69$). We find a mass outflow rate $\dot{M}_\mathrm{out}=0.65^{+0.44}_{-0.33}\,M_\odot \mathrm{yr}^{-1} = 2.0^{+1.3}_{-1.0}\, \dot{M}_\mathrm{acc}$ and a large instantaneous outflow kinetic power $\dot{E}_\mathrm{out}=4.4^{+4.4}_{-3.6} \times 10^{44}$ erg s$^{-1}$ = 24% $L_\mathrm{bol}$ = 18% $L_\mathrm{Edd}$ ($1 \sigma$ errors). We find that a major error contribution on the energetics is due to $r_0$, stressing the importance of an accurate determination through a proper spectral modeling, as done with WINE. Using 20 Swift (UVOT and XRT) observations and the simultaneous OM data from XMM-Newton, we also find that $\alpha_\mathrm{ox}$ undergoes large variations, with a maximum excursion of $\Delta\alpha_\mathrm{ox} =-0.7$, after the UFO is detected, leading to a remarkable X-ray weakness. This may point towards a starving of the inner accretion disk due to the removal of matter through the wind.