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A. A. Berlind, A. Conti (OSU)
We study the evolution of galaxy sizes in the Hubble Deep Field North (HDFN), a rich dataset which contains a large number of galaxies at high redshifts. We estimate the total galaxy magnitude using the Petrosian metric radius which is defined by the ratio of the average surface brightness within a radius r to the surface brightness at that radius. We adopt as our angular size estimator the radius within which half of the total galaxy light is contained. This definition of radius is relatively insensitive to redshift, making it a good probe of evolutionary changes in the galaxy size. We measure Petrosian half-light radii for all HDFN galaxies and find that their distribution is strongly peaked at very small sizes (~0.2 arcsec). In order to study the evolution of galaxy sizes we use published photometric redshifts. We find that the mean half-light radius of galaxies in the HDFN is independent of redshift in the redshift range from z=3 to z=0. This behaviour is caused by a combination of evolutionary and observational selection effects.
The author(s) of this abstract have provided an email address for comments about the abstract: aberlind@astronomy.ohio-state.edu