Abstract for Proposal 094218

Hunting for the wind features in NGC 4045 ULX with XMM-Newton and NuSTAR

Observations of a newly discovered hyperluminous X-ray source in the galaxy NGC 4045 at a distance of 32 Mpc have revealed an absorption line at E=8.56 keV detected with a significance of > 3.3 sigma. The origin of the absorption line appears likely to be by highly ionized iron with a blue shift of 0.2c, indicating an ultrafast outflow. However, the large equivalent width of the line, EW=-0.22 keV, requires extreme wind parameters. An alternative explanation is that the line is due to a cyclotron resonance scattering feature, produced by the interaction of X-ray photons with the powerful magnetic field of a neutron star. The goal of this proposal is to detect the additional wind features, such as a P-Cygni line profile, with a target of opportunity observation with XMM-Newton and NuSTAR.



Details on Observing Strategy and Trigger Criteria
Our trigger criterion for the ToO will be a detection of the source with a Swift/XRT with a count rate of 0.01 counts/s