Morphological Number Counts and Redshift Distributions to [FORMULA][F]I<26[/F][/FORMULA] from the Hubble Deep Field: Implications for the Evolution of Ellipticals, Spirals, and Irregulars

Citations Over TimeTop 1% of 1998 papers

Abstract

We combine the photometric redshift data of Fernandez-Soto et al. (1997) with the morphological data of Odewahn et al. (1996) for all galaxies with I 24. (2) Spiral galaxies are present in numbers consistent with zero- evolution predictions to I = 22. Beyond this magnitude some net- positive evolution is required. Although the number-counts are consistent with the passive-evolution predictions to I=26.0 the redshift distributions favor number AND luminosity evolution. (3) There is no obvious explanation for the late-type/irregular class and this category requires further subdivision. While a small fraction of the population lies at low redshift (i.e. true irregulars), the majority lie at redshifts, 1 1.5 mergers are frequent and, taken in conjunction with the absence of normal spirals at z > 2, the logical inference is that they represent the progenitors of normal spirals forming via hierarchical merging.

Related Papers

• → A New Catalog of Photometric Redshifts in the Hubble Deep Field(1999)360 cited
• → Redshifts in the Hubble Deep Field South(2003)17 cited
• → Galaxy Evolution in the Hubble Deep Field North and South(2006)
• Photometric Redshifts Applied to WFPC2 and NICMOS HDF Data(1999)