Seminar Presenter: Dr. Julia Kennefick, University of Arkansas, Fayetteville. PHYS 133, Paul Sharrah Lecture Hall, 4:00 PM
Since their discovery, quasars have been used both as astrophysical laboratories and cosmological markers. It was quickly realized after their discovery that the space density of quasars changes as a function of lookback time, and this was the main piece of evidence that finally put the death nail in steady state theories. We can now detect and count quasars out to a redshift of over 6 (over 12 billion years), but the exact form of the evolution is still uncertain, given the many assumptions that must be made concerning quasar properties. This talk gives an overview of quasar properties and a brief history of their study. I will then discuss my efforts to detect quasars at high redshift and my recent work to study their spectral energy distributions as a way to more accurately assess their numbers as a function of redshift and magnitude.
Refreshments will be served in the lobby at 3:30 pm.
Arkansas Center for Space and Planetary Sciences
202 Old Museum Building, University of Arkansas
Fayetteville, Arkansas 72701, USA
Tel. 479-575-7625 Fax. 479-575-7778 csaps@uark.edu
Since their discovery, quasars have been used both as astrophysical laboratories and cosmological markers. It was quickly realized after their discovery that the space density of quasars changes as a function of lookback time, and this was the main piece of evidence that finally put the death nail in steady state theories. We can now detect and count quasars out to a redshift of over 6 (over 12 billion years), but the exact form of the evolution is still uncertain, given the many assumptions that must be made concerning quasar properties. This talk gives an overview of quasar properties and a brief history of their study. I will then discuss my efforts to detect quasars at high redshift and my recent work to study their spectral energy distributions as a way to more accurately assess their numbers as a function of redshift and magnitude.