Previous abstract Next abstract
A two color survey of 9 fields of the first epoch Palomar Sky Survey, centered on the North Galactic Pole, has been performed with the Minnesota Automated Plate Scanner. Following photometric calibration using both direct comparison with galaxy surface photometry and a stellar PSF adjustment technique, an innovative automated classification method is used to establish catalogs of stars and galaxies to approximate magnitude limits of O$=20.5$ and E$=20.0$. Hubble type-dependent photometric properties such as mean integrated color, mean surface brightness, and concentration index are extracted from the O and E images of galaxies with an isophotal magnitude brighter than O $= 20.5$.
The resultant photometric catalog of galaxies is used to study the large scale distribution of galaxies at the NGP with a variety of number count mapping methods. We primarily investigate the relationship between local galaxy number density and trends among type-dependent photometric properties in an effort to detect and quantify the well-known galaxy morphology-density relation. A multi-dimensional analysis of these quantities is performed using neural network pattern classifiers in an effort to perfect a viable galaxy morphology classifier for the APS POSS I material. We study the distribution of our automatically classified sample as a function of local galaxy number density.
Thursday program listing