The number densities of white dwarf stars in globular clusters can be as high as 104 pc-3, allowing for a significant rate of direct impacts, perhaps as high as 10-100 per year. The observations by Chomiuk et al. (2008) of globular clusters in NGC 7457, an S0 galaxy, have detected a supernova remnant that exhibits the hallmarks of a type Ia supernova, and given the tiny fraction that globular clusters contribute to the total mass density of the universe, this may indicate a unique pathway for producing supernovae. Using a Smooth Particle Hydrodynamics code, we propose to examine a variety of white dwarf - white dwarf collision scenarios in 3D as a relatively unexplored avenue for nova/supernova production. Our simulations will span a large parameter space of white dwarf masses and collisional parameters in order to establish trends and rates for these kinds of interactions and make predictions for future transient observations. With the impending, substantial increase in type Ia supernova detections from projects such as NASAs Joint Dark Energy Mission (JDEM) and the Large Synoptic Survey Telescope (LSST), the utility of these missions will depend greatly on the ability to accurately calibrate these supernovae as standardcandles. A detailed, theoretical examination of white dwarf collisions will be essential in reducing the scatter in the Hubble diagram, with which cosmologists age-date and measure the expansion velocity of the Universe.
|Effective start/end date||9/1/10 → 8/31/11|
- NASA: Goddard Space Flight Center: $29,795.00
white dwarf stars