  We present a detailed X-ray spectral study of the quasar PG 1211+143 based on
Chandra High Energy Transmission Grating Spectrometer (HETGS) observations
collected in a multi-wavelength campaign with UV data using the Hubble Space
Telescope Cosmic Origins Spectrograph (HST-COS) and radio bands using the
Jansky Very Large Array (VLA). We constructed a multi-wavelength ionizing
spectral energy distribution using these observations and archival infrared
data to create XSTAR photoionization models specific to the PG 1211+143 flux
behavior during the epoch of our observations. Our analysis of the
Chandra-HETGS spectra yields complex absorption lines from H-like and He-like
ions of Ne, Mg and Si which confirm the presence of an ultra-fast outflow (UFO)
with a velocity ~ $-$17,300 km s$^{-1}$ (outflow redshift $z_{\rm out}$ ~
$-$0.0561) in the rest frame of PG 1211+143. This absorber is well described by
an ionization parameter $\log \xi$ ~ 2.9 erg s$^{-1}$ cm and column density
$\log N_{\rm H}$ ~ 21.5 cm$^{-2}$. This corresponds to a stable region of the
absorber's thermal stability curve, and furthermore its implied neutral
hydrogen column is broadly consistent with a broad Ly$\alpha$ absorption line
at a mean outflow velocity of ~ $-$16,980 km s$^{-1}$ detected by our HST-COS
observations. Our findings represent the first simultaneous detection of a UFO
in both X-ray and UV observations. Our VLA observations provide evidence for an
active jet in PG 1211+143, which may be connected to the X-ray and UV outflows;
this possibility can be evaluated using very-long-baseline interferometric
(VLBI) observations.
