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

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, $\log \hat{I}¾=5.53_{-0.05}^{+0.04}$ 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 $v_0=0.24_{-0.06}^{+0.08}c$ (90% c.l. errors), and attains an average velocity $v_{\mathrm{avg}}=0.152c$. 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 ($\hat{I}¸>72^{\circ }$) and the covering factor ($C_{\mathrm{f}}>0.69$). We find a mass outflow rate ${\dot{M}}_{\mathrm{out}}=0.65_{-0.33}^{+0.44}{M}_{\odot }{\mathrm{yr}}^{-1}=2.0_{-1.0}^{+1.3}{\dot{M}}_{\mathrm{acc}}$ and a large instantaneous outflow kinetic power ${\dot{E}}_{\mathrm{out}}=4.4_{-3.6}^{+4.4}\times 10^{44}$ erg s${}^{-1}$ = 24% $L_{\mathrm{bol}}$ = 18% $L_{\mathrm{Edd}}$ ($1\ddot{I}ƒ$ 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 $\hat{I}{\pm }_{\mathrm{ox}}$ undergoes large variations, with a maximum excursion of $\hat{I}”\hat{I}{\pm }_{\mathrm{ox}}=-0.7$, 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.

10 pages, 6 figures, 5 tables, accepted for publication in A&A