The Galactic Centre source IRS 13E: A post-LBV Wolf-Rayet colliding wind binary?

Abstract

IRS 13E is an infrared, mm and X-ray source in the Galactic Centre. We present the first Chandra X-ray spectrum for IRS 13E and show that it is consistent with a luminous and highly absorbed X-ray binary system. Since the X-ray luminosity is too large for a solitary star, our interpretation is that of an early-type long-period binary with strong colliding winds emission. This naturally explains the observed X-ray spectrum and count rate as well as its lack of significant short term vriability. Due to the short lifetime of any nebula 0.2 pc from the putative central super-massive black-hole, we argue that the primary of IRS 13E has exited the LBV phase in the last few thousand years.