Phase-resolved Spectroscopy of Massive stars
X-ray spectra of WR 25 as observed from MOS and PN detectors along with the best fit folded 2T vapec model at nine epochs. WR 25 was observed with the PN detector only at three phases, namely 0.360, 0.438, and 0.735. The PN spectra are shown on the top at these three epochs. The lower panels show the residual in terms of the ratio of the data and model. The emission lines of Ne x, Mg xi+xii, Si iii+iv, S xv+xvi, Ar xvii+xviii, Ca xix+xx, and Fe (K-shell) are seen in the spectra.
[Image Credit: Pandey, Pandey, & Karmakar et al. (2014)]