Are disk galaxies the progenitors of giant ellipticals?

Abstract

A popular formation scenario for giant elliptical galaxies proposes that they might have formed from binary mergers of disk galaxies. Difficulties with the scenario that emerged from earlier studies included providing the necessary stellar mass and metallicity, maintaining the tight color-magnitude relation and avoiding phase space limits. In this paper we revisit the issue and put constraints on the binary disc merger scenario based on the stellar populations of disc galaxies. We draw the following conclusions: Low redshift collisionless or gaseous mergers of present day Milky Way like disc galaxies do not form present day elliptical galaxies. Binary mergers of the progenitors of present day Milky Way like disc galaxies can have evolved into intermediate mass elliptical galaxies ($M<M_{\ast }$) if they have merged earlier than $\approx$ 3-4 Gyrs ago. Assuming that most present day disk galaxies formed in a similar way to the Milky Way model presented here, more massive giant ellipticals in general can not have formed from binary mergers of the progenitors of present day disc galaxies. A major reason for these conclusions is that the mass in metals of typical disk galaxy is approximately a factor of 4-8 smaller than the mass in metals of a typical early-type galaxy and this ratio grows to larger values with increasing redshift.

accepted by ApJ, to appear in Jan 2009

References in corpus (5)

• Equal- and unequal-mass mergers of disk and elliptical galaxies with black holes
• Dissipation and Extra Light in Galactic Nuclei: I. Gas-Rich Merger Remnants
• The ACS Fornax Cluster Survey. II. The Central Brightness Profiles of Early-Type Galaxies: A Characteristic Radius on Nuclear Scales and the Transition from Central Luminosity Deficit to Excess
• The importance of dry and wet merging on the formation and evolution of elliptical galaxies
• Are disk galaxies the progenitors of giant ellipticals?

Cited by in corpus (5)

• Multiple minor mergers: formation of elliptical galaxies and constraints for the growth of spiral disks
• Dissipation and Extra Light in Galactic Nuclei: II. 'Cusp' Ellipticals
• Are disk galaxies the progenitors of giant ellipticals?
• Galaxy mergers at high resolution: From elliptical galaxies to tidal dwarfs and globular clusters
• The Galactic Mergers and Gravitational Unbound Populations