Suzaku Monitoring of the Seyfert 1 Galaxy NGC5548: Warm Absorber
  Location and its Implication for Cosmic Feedback
  (Abridged) We present a two month Suzaku X-ray monitoring of the Seyfert 1
galaxy NGC 5548. The campaign consists of 7 observations. We analyze the
response in the opacity of the gas that forms the ionized absorber to ionizing
flux variations. Despite variations by a factor of 4 in the impinging
continuum, the soft X-ray spectra of the source show little spectral
variations, suggesting no response from the ionized absorber. A detailed time
modeling confirms the lack of opacity variations for an absorbing component
with high ionization. Instead, the models tentatively suggest that the
ionization parameter of a low ionization absorbing component might be changing
with the ionizing flux, as expected for gas in photoionization equilibrium.
Using the lack of variations, we set an upper limit of n_e <2.0E7 cm-3 for the
electron density of the gas forming the high ionization, high velocity
component. This implies a large distance from the continuum source (R > 0.033
pc). If the variations in the low ionization component are real, they imply n_e
>9.8E4 cm-3 and R < 3 pc. We discuss our results in terms of two different
scenarios: a large scale outflow originating in the inner parts of the
accretion disk, or a thermally driven wind originating much farther out. Given
the large distance of the wind, the implied mass outflow rate is also large (Mw
> 0.08 Maccr). The associated total kinetic energy deployed by the wind in the
host galaxy (>1.2E56 erg) can be enough to disrupt the interstellar medium,
possibly regulating large scale star formation. The total mass and energy
ejected by the wind is still lower than the one required for cosmic feedback,
even when extrapolated to quasar luminosities. Such feedback would require that
we are observing the wind before it is fully accelerated.
