Hello! My name is Ray Garner and I am a postdoc in the Astronomy Group at Texas A&M University in College Station, Texas. I am working with Dr. Rob Kennicutt on the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey (SIGNALS), a survey of HII regions across ~60 galaxies. You can check out the survey paper here.
Before I arrived in College Station, I was a graduate student at Case Western Reserve University in Cleveland, Ohio working with Prof. Chris Mihos on a detailed analysis of the Pinwheel Galaxy (M101) and its small satellite group using the deep, wide-field, narrowband imaging capabilities of the Burrell Schmidt 24/36-inch telescope.
Briefly, my thesis utilizes narrowband images of Hα, Hβ, [OIII]λλ4959,5007, and [OII]λλ3726,3729. These images allowed me to search the entire M101 Group for outlying, intragroup star-forming regions (finding none), measure the oxygen abundance gradient of M101 (suggesting a broken gradient at $R_{25}$), and constrain stellar ages throughout the entire disk (finding a very dynamic spiral pattern). You can read more about that research below, or click here.
Before attending CWRU, I was a student at Furman University in Greenville, South Carolina where I graduated with a B.S. in Physics, Summa Cum Laude. While there, I completed research in general relativity with Dr. Bill Baker (ret.). During the summer of 2017, I attended a Research Experience for Undergraduates (REU) at Indiana University in Bloomington, Indiana. There, I worked on ionized gas kinematics of nearby, low-mass galaxies with the late Dr. Liese van Zee.
PhD in Astronomy, 2023
Case Western Reserve University
BS in Physics, 2018
Furman University
Using deep, narrowband imaging of the nearby spiral galaxy M101, we present stellar age information across the full extent of the disk of M101. Our narrowband filters measure age-sensitive absorption features such as the Balmer lines and the slope of the continuum between the Balmer break and 4000 Å break. We interpret these features in the context of inside-out galaxy formation theories and dynamical models of spiral structure. We confirm the galaxy’s radial age gradient, with the mean stellar age decreasing with radius. In the relatively undisturbed main disk, we find that stellar ages get progressively older with distance across a spiral arm, consistent with the large-scale shock scenario in a quasi-steady spiral wave pattern. Unexpectedly, we find the same pattern across spiral arms in the outer disk as well, beyond the corotation radius of the main spiral pattern. We suggest that M101 has a dynamic, or transient, spiral pattern with multiple pattern speeds joined together via mode coupling to form coherent spiral structure. This scenario connects the radial age gradient inherent to inside-out galaxy formation with the across-arm age gradients predicted by dynamic spiral arm theories across the full radial extent of the galaxy.