More About This Research

Mapping Emission in Algol Binaries

The simultaions were performed using a hydrodynamics code called VH-1. This code was written by the Virginia Institute for Theoretical Astrophysics here at the University of Virginia. VH-1 uses the Piecewise Parabolic Method of Collela & Woodward (1984, J. Comp. Phys., 54, 174) implemented with a remap onto a fixed Eulerian grid. An explanation of the code can be found in Richards & Ratliff (1998, Ap. J., 493, 326). A copy of the code can be obtained from John Blondin at North Carolina State University. The manual for the code and other general information can also be found at that site.

Using the PPM hydrodynamics code, Mark Ratliff and Mercedes Richards created simulations of several systems including Persei, which is the prototype of the Algol class of interacting binaries. The physical parameters of this system are as follows:

Parameter	Value
Mass of Primary
Radius of Primary
Mass of Secondary
Radius of Secondary
Orbital Separation
Orbital Period

The results of the simulations can be seen in the images below. Both images show light emitted by gas via the H atomic transition. The first image displays this emission plotted in Cartesian Coordinates. The second image displays the same emission plotted in Velocity Coordinates. Note that the two white circles in the Velocity map are merely reference circles. In both images, albeit in different locations, the gas stream and the irregular disk formed by the accretion process can be seen.

Cartesian Map Velocity Map

The purpose of mapping the emission in these systems is so that they can be compared with Doppler tomograms produced by Mercedes Richards. Presently, you can find tomograms of U Sge, RS Vul, U CrB, and Persei in Richards, M. T., Albright, G. E., & Bowles, L. M. 1995, ApJ L, 438, L103.