Astronomy Seminar
| Date/Time: | Friday, 31 Oct 2014 at 4:10 pm |
|---|---|
| Location: | 3 Physics |
| Contact: | Steve Kawaler |
| Phone: | 515-294-5440 |
| Channel: | College of Liberal Arts and Sciences |
| Categories: | Lectures |
| Actions: | Download iCal/vCal | Email Reminder |
Relatively few widely separated substellar-mass companions of planetary systems are known. These companions can alter the dynamics of planets through Kozai-mechanism-style secular perturbations, and may be a cause of the high mean eccentricity of exoplanets. The orbital periods of such companions are expected to be of the order of tens to thousands of years, making them undetectable by time-domain observations such as transit- and radial velocity searches. We have conducted a Spitzer/Infrared Array Camera (IRAC) 3.6 and 4.5 micron imaging search for widely separated substellar-mass companions with projected separation between 5 to 40 arcsec from their parent star. The 36 stars in my sample range from 4 to 15 pc from the sun, giving a typical sensitivity of 10 MJ for objects with an orbital radius in the range of 50 to 300 au. This search required advanced PSF-subtraction techniques in order to minimize the inner working angle and increase sensitivity. In this talk I present the results of this search and discuss the data analysis methods we developed for it.