Abstract

The origin of color gradients in elliptical galaxies is examined by comparing model gradients with those observed in the Hubble Deep Field. The models are constructed so as to reproduce color gradients in local elliptical galaxies either by a metallicity gradient or by an age gradient. By looking-back a sequence of the color gradient as a function of redshift, the age-metallicity degeneracy is solved. The observed color gradients in elliptical galaxies at z = 0.1 to 1.0 agree excellently with those predicted by the metallicity gradient, while they deviate significantly from those predicted by the age gradient even at z ~ 0.3, and the deviation becomes larger with increasing redshift. This result does not depend on cosmological parameters and parameters for an evolutionary model of an elliptical galaxy within a reasonable range. Thus our results clearly indicate that the origin of color gradients is not age but stellar metallicity.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.