Abstract for Proposal 094209
Searching for a Wind in the Bright State of 4U1957+11
How does a black hole transit from a jet-producing system in a spectrally
hard state to a soft state? Under what conditions does this state produce
winds, and when can we observe these winds? Are wind launching mechanisms
dominated by radiative, thermal, or magnetic driving? Seeking answers
to these questions, we propose a triggered XMM/NuSTAR observation of
thepersistently bright LMXB 4U1957+11, which is hypothesized to harbor
a near-maximally spinning black viewed close to edge-on. It has been
observed with high resolution X-ray spectroscopic instruments in low
flux/minimal hard tail states. We will use MAXI monitoring to target a
bright soft state with a significant non-disk contribution, potentially
indicative of an outflowing corona/wind, and search for spectroscopic
signatures of a wind.
Details on Observing Strategy and Trigger Criteria
We will use MAXI monitoring to target a bright soft state with a significant
non-disk contribution, potentially indicative of an outflowing corona/wind,
and search for spectroscopic signatures of a wind.