NASA Scientific and Technical Aerospace Reports

In this paper, the authors describe the use of data mining techniques to search for radio-emitting galaxies with a
bent-double morphology. In the past, astronomers from the FIRST (Faint Images of the Radio Sky at Twenty-cm) survey
identified these galaxies through visual inspection. This was not only subjective but also tedious as the on-going survey now
covers 8000 square degrees, with each square degree containing about 90 galaxies. In this paper, they describe how data
mining can be used to automate the identification of these galaxies. They discuss the challenges faced in defining meaningful
features that represent the shape of a galaxy and their experiences with ensembles of decision trees for the classification of
bent-double galaxies.
NTIS
Galaxies; Radio Galaxies; Data Processing
20040050609 Smithsonian Astrophysical Observatory, Cambridge, MA, USA
Evolution of Galaxies and the Star Formation Rate in the Infrared
Pahre, Michael A.; Oliversen, Ronald J., Technical Monitor; March 2004; 6 pp.; In English
Contract(s)/Grant(s): NAG5-10777
Report No.(s): Rept-3; No Copyright; Avail: CASI; A02, Hardcopy
A central goal of extragalactic observational astronomy is to understand how normal galaxies evolve with redshift, and
particularly when galaxies formed their stars. While optical and rest-frame UV observations have begun to address these
issues, the interpretation of such data is particularly challenging because of the sensitivity to dust obscuration (at optical and
UV wavelengths). The absorbed light is reradiated at IR wavelengths, hence the optimal indicators of the star-formation rate
(SFR) is at a rest-frame wavelength of approx. 60 microns. The Spitzer Space Telescope mission is beginning to revolutionize
the study of the global properties and evolution of galaxies. Spitzer reaches nearly two orders of magnitude more sensitivity
than previous IR space missions. This research program is to study the SFR using statistical samples of galaxies in the local
universe, at intermediate redshifts, and set the stage for continuing studies up to z=5. The overall research program is divided
into three main investigations: A Mid-IR Hubble Atlas and SFR estimators in the local universe, Evolution of the SFR at 0