X-ray Insights into Colliding Wind Binaries: A Comparative Study of WR 25, Gamma2 Vel, and Related Systems

X-ray emission from wind collisions in massive binaries provides unique physical constraints on mass-loss parameters, such as velocities and densities at defined distances from the star, as well as insight into how these parameters change with stellar separation and time. X-ray emission from colliding wind binaries is produced by a strong bow shock where the two fast radiatively driven winds from the stars collide in the space between them. We are conducting a comprehensive analysis of colliding wind binaries using X-ray observations from the current generation of X-ray telescopes, by fitting the observations with two well-characterized stars. In this talk, we focus on the Chandra results of WR 25, and the recent NICER monitoring of Gamma2 Vel. We will also compare the behavior of these stars against other colliding wind binary systems like WR 137, WR 138, WR 147, and WR 133.