Felten conducted theoretical high energy astrophysics research related to the interstellar and intergalactic medium, galaxies and cosmology.
James Edgar Felten, astrophysicist, consultant and educator, died on Friday March 7, 2014. He was 79.
Felten was born on September 8, 1934 in Duluth, Minnesota, the son of Edgar George and Myrtle Clarice (Thompson) Felten. Felten earned his bachelor’s degree (cum laude) in physics and mathematics at the University of Minnesota, Duluth, in 1956 and went on to graduate school at Cornell University. There, he earned his Ph.D. in astrophysics in 1965 under the mentorship of Philip Morrison. In 1963, Felten and Morrison published a paper together calling attention to the “inverse Compton effect,” in which a collision with a relativistic electron can raise a radio frequency or optical photon to a much higher energy. It can be an important source of cosmic X-rays and gamma rays .
Felten’s first academic position was as an assistant research physicist at the University of California, San Diego (1965–8). There, his research focused on the interaction between electrons and the magnetic field in the Galactic halo. He then went to the Institute for Theoretical Astronomy at Cambridge University as a visiting fellow from 1968–70. There, he and Virginia Trimble were office mates. As Virginia humorously recalls, Felten injured his ankle climbing a fence to get at tea and bakery goods at the Observatory Director’s house .
Felten held several positions at the University of Arizona (UA) and Steward Observatory: visiting associate professor (1970–2), associate astronomer (1970–5), and associate professor of astronomy (1972–5). In Tucson, he was an active player in a number of Gilbert and Sullivan operettas, an interest he cultivated throughout his life.
Following his work at UA, Felten went to the NASA Goddard Space Flight Center where he was a National Research Council senior research associate (1976–8). Between 1978 and 1985, he held a series of research positions, first with the University of Maryland (visiting professor of astronomy, senior research associate, and technical consultant), then with the Universities Space Research Association in Greenbelt, Maryland (1989–91). There, he was also an active member of the Greenbelt Players Victorian Lyric Opera Company.
Felten was a fellow of the APS, as well as a member of the AAS and the IAU. He was a member of the AAS High Energy Astrophysics Division advisory committee (1972–3). In the IAU, he was a member of over a dozen divisions and commissions, most of which were relevant to his interests in high energy astrophysics, extragalactic astronomy and cosmology.
Felten continued to publish the occasional commentary letter and scientific paper until the late 1990s. His last paper listed in the NASA ADS, “Nonnucleosynthetic Constraints on the Baryon Density and Other Cosmological Parameters” (1999; ) explored the results of using only observable quantities to constrain cosmological models.
Contributed material from Buell Jannuzi, Bill Hoffmann, and Ed Olszewski and George Rieke (all at UA and/or Steward Observatory) is gratefully acknowledged.
See also Felten’s AstroGen entry.
At the time of writing, no photograph of the decedent could be located. If you’re able to provide one, please contact the HAD Vice-Chair.