HI-Bearing Ultra-diffuse Galaxies: A Look Into AGC 749290
Arts and Sciences
Department of Physics and Astronomy
This research examines properties of ultra-diffuse galaxies (UDGs) in order to discover more about why and how these galaxies exist. UDGs are galaxies that have very little star content for their given radius, so they appear very dim optically but can be observed in radio wavelengths. We worked with data taken from the Very Large Array, which observed radio emission from gas within the galaxies. To analyze the data, we first used CASA, a specific radio astronomy software, to remove interference from the data, calibrate the data, and create images that show the gas distribution in the galaxies. From CASA, we were able to obtain spectra and velocity maps of the galaxies, which we then used to measure the galaxies' gas mass and motions using code in IDL. Through this process, we determined that the galaxies are rotating, their gas content extends past what we can see optically, and in one instance, the gas distribution is misaligned from what we see in the optical image, which is not a typical characteristic. Future work involves analyzing these galaxies deeper and comparing multiple properties such as color, rotation rate, gas mass ratios, and dark matter content to that of typical galaxies and find where there are differences. By measuring and comparing each of these properties in these atypical galaxies, we will have better constraints on galaxy models which will allow us to more fully understand galaxy formation and evolution.
Gault, Lexi, "HI-Bearing Ultra-diffuse Galaxies: A Look Into AGC 749290" (2018). Summer Interdisciplinary Research Symposium. 37.