Professor of Astronomy
The Ohio State University, Department of Astronomy
Originally from the Indian Wells Valley in California's Northern Mojave Desert, I attended Sherman E. Burroughs High School (Class of 1979) in Ridgecrest, California, otherwise known as the "Gateway to Death Valley", and home of the China Lake Naval Air Weapons Station (it was just NOTS, then NWC, when I was there). While at China Lake I was a member of the China Lake Astronomical Society, the folks who helped give me a start in Astronomy, and Boy Scout Troop 35, to whom I owe my abiding love of the outdoors. In 1979 I left the desert to attend Caltech, where I received my BS in Physics in 1983. At Caltech I was a member of Dabney House, and a sometime member of the infamous InfraRed Army. I then got out of Pasadena and headed north along the coast to UC Santa Cruz, where I received my PhD in Astronomy & Astrophysics in 1988. After a year at the University of Texas at Austin as a McDonald Fellow, I arrived at The Ohio State University as a postdoc in 1989, eventually joining the faculty of the Astronomy Department in 1992 as an Assistant Professor. I have been a Full Professor of Astronomy at OSU since 2003.
My primary research is concerned with the astrophysics of active galactic nuclei and gaseous nebulae as revealed through imaging and spectrophotometry at optical, UV, and infrared wavelengths with ground-based and space-based telescopes. I've been concerned with three lines of research. The first seeks to refine measurments of the masses of supermassive black holes in nearby active galaxies with the goal of calibrating the key scaling relations that will allow us to extend local methods out to cosmological distances. The second uses the Hubble and Chandra space telescopes to study how local active nuclei are fed by gas from their host galaxies, and how that activity in turn feeds back upon their hosts. The third is to use precision spectrophotometry to measure direct and empirical elemental gas-phase abundances in star formation regions to trace the chemical evolution history of galaxies.
Closer to home, I have joined in the study of planets around other stars. I am part of the MicroFUN collaboration based at Ohio State that has organized a worldwide network of amateur and professional telescopes to make coordinated observations to search for extrasolar planetary systems using gravitational microlensing. My current and past students and I are also engaged searches for and detailed follow-up studies of up transiting exoplanets, through the KELT North, KELT South, and DEMONEXT projects, as well as exploring new techniques using adaptive optics.
Research requires the best data, and to provide that data I am actively involved in the design and construction of advanced astronomical instruments, including development of software for image processing, spectral analysis, and instrument control & data acquisition. Instruments I have helped develop are in regular use at the MDM Observatory in Arizona and on the SMARTS telescopes in Chile. My biggest project to date has been the two Multi-Object Double Spectrographs (MODS) we built at OSU for the Large Binocular Telescope on Mt. Graham in Arizona. I am currently leading the development of two robotic fiber positioner systems for SDSS-V.
Prof. Ryden is under contract with Cambridge University Press for the first 4 volumes in the series, starting with Interstellar and Intergalactic Medium coming out in Spring 2021.