Repository landing page

We are not able to resolve this OAI Identifier to the repository landing page. If you are the repository manager for this record, please head to the Dashboard and adjust the settings.

The halo distribution of 2dF galaxies

Abstract

We use the clustering results obtained by Madgwick et al. (2003) for a sample of 96 791 galaxies from the 2dF Galaxy Redshift Survey with redshift 0.01 < z < 0.15 to study the distribution of late-type and early-type galaxies within dark matter haloes of different mass. Within the framework of our models, galaxies of both classes are found to be as spatially concentrated as the dark matter within haloes, even though, while the distribution of star-forming galaxies can also allow for some steeper profiles, this is ruled out drastically in the case of early-type galaxies. We also find evidence for morphological segregation, as late-type galaxies appear to be distributed within haloes of mass-scales corresponding to groups and clusters up to about two virial radii, whereas passive objects show a preference to reside closer to the halo centre. If we assume a broken power law of the form 〈Ngal〉(m) = (m/m0) for mcut≤m < m0 and 〈Ngal〉(m) = (m/m0) at higher masses to describe the dependence of the average number of galaxies within haloes on the halo mass, fits to the data show that star-forming galaxies start appearing in haloes of masses mcut≃ 1011 M⊙, much smaller than what is obtained for early-type galaxies (mcut≃ 1012.6 M⊙). In the high-mass regime m≥m0, 〈Ngal〉 increases with halo mass more slowly (α2≃ 0.7) in the case of late-type galaxies than for passive objects which present α2≃ 1.1. The above results imply that late-type galaxies dominate the 2dF counts at all mass-scales. We stress that — at variance with previous statements — there is no degeneracy in the determination of the best functional forms for ρ(r) and 〈Ngal〉, as they affect the behaviour of the galaxy-galaxy correlation function on different scale

    Similar works

    This paper was published in RERO DOC Digital Library.

    Having an issue?

    Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.