Zion Thomas Abstract
Zion Thomas
August 6, 2021
Creating Globular Cluster Catalogs Abstract
Zion Thomas, Creating Globular Cluster Catalogs in PHANGS Galaxies (Rupali Chandar)
The PHANGS-HST group studies thirty-eight spiral galaxies in the universe using data from the Hubble Space Telescope. The members of the group that are focused on creating catalogs of the star clusters in these galaxies provided our research group with data to use to determine the age of these clusters based on their color, using wavelength magnitudes, with ancient red clusters being the targets of the project. Using Python coding, images of the galaxies on the interactive Sundog web tool and color-color diagrams, we were able to pick out all of the objects that could fall in the ten- to twelve-billion-year-old range. The ultraviolet, blue, visible and infrared filters were used to create the color-color diagrams, with color cuts of B-V=0.50 and V-I=0.73 to find the reddest objects. By finding these objects we were able to start creating catalogs of these ancient clusters and determine the percentages of how many clusters in each galaxy are ancient. This helps other astronomers age-date the galaxies and look for conditions for star formation. The end goal of this project is to obtain data for all thirty-eight galaxies in the PHANGS group and publish the research for other scientists’ use.