NuSTAR monitoring of Eta Carinae
Abstract
The eta Carinae binary system hosts one of the most massive stars featuring the highest known mass-loss rate. This dense wind encounters the much faster wind expelled by the stellar companion, dissipating mechanical energy in the shock and accelerating particles. NuSTAR observed eta Carinae ten times around the 2014 periastron. The X-ray flux varied in a similar way as observed during the previous periastrons, increasing to a maximum a few days before periastron and decreasing steeply to a deep minimum before recovering. NuSTAR gives us access to the continuum, obscuration and to Iron line emission. We used a two-temperature model to fit the continuum originating from the wind-wind collision (WWC) region. After correction for the obscuration, we find that the intrinsic continuum feature a short period of reduced emission and can therefore probe the collapse of the WWC region close to periastron and its occultation by the primary star. The Fe Kα line is probing independently the response of the intrinsic continuum variability and the location where this reprocessing takes place.
- Publication:
-
The X-ray Universe 2017
- Pub Date:
- October 2017
- Bibcode:
- 2017xru..conf..309P