Astronomy Seminar
| Date/Time: | Friday, 07 Nov 2014 at 4:10 pm |
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| Location: | 3 Physics |
| Phone: | 515-294-5440 |
| Channel: | College of Liberal Arts and Sciences |
| Categories: | Lectures |
| Actions: | Download iCal/vCal | Email Reminder |
Accurate distances are among the most important measurements in astronomy, yet we still lack a self consistent distance scale to galactic globular clusters (GGCs). While distances have been measured using a variety of methods, each of them are valid for only a subset of GGCs. As part of the Carnegie RR Lyrae Program, we aim to resolve this by providing a calibration of the period-luminosity (PL) relation for RR Lyrae stars in the mid infrared (MIR) wavelengths. Advantages of working in the MIR include a reduced effect of extinction, lower amplitude, and a significantly smaller intrinsic scatter of the PL relation. We have conducted a survey at 3.6 and 4.5 ?m of 31 GGCs using the Infrared Array Camera (IRAC) onboard Spitzer Space Telescope. In this talk, I will discuss the analysis and new distance determination of M4, the closest GGC.