Distant galaxies appear to be more ragged and disorganized than closer ones. These appearances could be legitimate features, or effects from the expansion of the universe, which progressively shifts ultraviolet photons from distant galaxies into the range sensed by the optical detectors. Madore is tackling this problem through observations and computer modeling.
To model the effects of dust, Madore and colleagues are developing a computer program with a three-dimensional radiative transfer to determine galactic morphology at ultraviolet, optical, near-infrared, and thermal-infrared wavelengths. The program uses an innovative technique to compensate for small-particle scattering in the interstellar medium and for behavior in a randomly clumped medium such as a galaxy's spiral arm. The program calculates the absorption, scattering, and re-radiation exactly and produces realistic high-resolution galaxy images at typically used wavelengths. The researchers next plan to generate images at other wavelengths.
Madore is also a co-investigator on NASA's GALaxy EXplorer (GALEX) satellite, which is surveying the high-galactic-latitude sky in two ultraviolet bandpasses. It is additionally targeting hundreds of the nearest and largest galaxies for special studies. Unexpected structures (e.g., new sites of star formation) are being discovered in the outermost regions of many previously well-studied galaxies. This work is allowing researchers to better understand the contemporary structure of galaxies and, ultimately, their secular evolution.
- Ph.D. in Astronomy, 1974, University of Toronto
- M.Sc. in Astronomy, 1971, University of Toronto
- B.S. Astronomy and Physics, 1969, University of Southern California