The stellar ages of NGC 5474 as measured through narrowband filter equivalent widths.Abstract
Using deep, narrowband imaging of the nearby peculiar spiral galaxy NGC 5474, we present stellar age information across its disk and offset bulge. As shown in earlier work on M101, our narrowband filters measure age-sensitive absorption features such as Balmer absorption. We separate our study of NGC 5474 into its main disk containing its offset bulge, and the faint outer disk. We show that the main disk is relatively well-mixed in ages, showing no radial age changes. Meanwhile, the offset bulge is distinct from the main disk, showing only old ages. We explore the ages of the outer disk as a function of angle, showing that it is relatively young with the side towards M101 showing the youngest ages. We interpret this in the context of the M101-NGC 5474 interaction and the potential extragalactic nature of the offset bulge.
Ray Garner
TAMU Astronomy Postdoctoral Researcher
I’m a scientist, Star Wars fan, and amateur photographer raised in Georgia. My research interests include galaxy evolution, star formation, satellite galaxies, and nebular diagnostics.