Evidence of Elevated X-Ray Absorption Before and During Major Flare
  Ejections in GRS 1915+105
  We present time resolved X-ray spectroscopy of the microquasar GRS1915+105
with the MAXI observatory in order to study the accretion state just before and
during the ejections associated with its major flares. Radio monitoring with
the RATAN-600 radio telescope from 4.8 - 11.2 GHz has revealed two large steep
spectrum major flares in the first eight months of 2013. Since, the RATAN
receives one measurement per day, we cannot determine the jet forming time
without more information. Fortunately, this is possible since a distinct X-ray
light curve signature that occurs preceding and during major ejections has been
determined in an earlier study. The X-ray luminosity spikes to very high levels
in the hours before ejection then becomes variable (with a nearly equal X-ray
luminosity when averaged over the duration of the ejection) during a brief 3 to
8 hour ejection process. By comparing this X-ray behavior to MAXI light curves,
we can estimate the beginning and end of the ejection episode of the strong
2013 flares to within $\sim$3 hours. Using this estimate in conjunction with
time resolved spectroscopy from the data in the MAXI archives allows us to
deduce that the X-ray absorbing hydrogen column density increases significantly
in the hours preceding the ejections and remains elevated during the ejections
responsible for the major flares. This finding is consistent with an
out-flowing wind or enhanced accretion at high latitudes.
