How Do Galaxies Form?

Sidney van den Bergh

Home/Archive/arXiv

arXiv · 0810.3644

How Do Galaxies Form?

Sidney van den Bergh

View original source ↗Read source document ↗Export metadata ↓

Abstract

It is currently believed that galaxies were assembled via chaotic hierarchical mergers between massive cold dark matter halos, in which baryonic star forming matter was embedded. One would therefore expect the properties of individual galaxies to be determined by numerous independent factors such as star forming history, merger history, mass, angular momentum, size and environment. It is therefore surprising to find that galaxies actually appear to form an (almost) one parameter family in which galaxy mass is the dominant factor.

Explore related subjects

astro-ph

Keep this discovery

BibTeX RIS

Sidney van den Bergh. 2008-10-20. How Do Galaxies Form?. https://arxiv.org/abs/0810.3644

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2012

Sachs-Wolfe effect in some anisotropic models

In this work it is shown for some spatially homogeneous but anisotropic models how the inhomogeneities in the distribution of matter on the surface of the last scattering produce anisotropies in large angular scales (larger than $\vartheta \gtrsim 2^\circ$) which do not differ from the ones produced in Friedmann-Lemaître-Robertson-Walker (FLRW) geometries. That is, for these anisotropic models, the imprint left on the cosmic microwave background radiation (CMBR) by the primordial density fluctuations, in the form of a fractional variation of the temperature of this radiation, is governed by the same expression as the one given for FLRW models. More precisely, under adiabatic initial conditions, the classical Sachs-Wolfe effect is recovered, provided the anisotropy of the overall expansion is small. This conclusion is in agreement with previous work on the same anisotropic models where we found that they may go through an `isotropization' process up to the point that the observations are unable to distinguish them from the standard FLRW model, if the Hubble parameters along the orthogonal directions are assumed to be approximately equal at the present epoch. Here we assumed upper bounds on the present values of anisotropic parameters imposed by COBE observations.

astro-ph↗

arXiv2012

On chirality of the vorticity of the Universe

We study chirality of the vorticity of the Universe within the Einstein-Cartan cosmology. The role of the spin of fermion species during the evolution of the Universe is studied by averaged spin densities and Einstein-Cartan equations. It is shown that spin density of the light Majorana neutrinos acts as a seed for vorticity at early stages of the evolution of the Universe. Its chirality can be evaluated in the vicinity of the spacelike infinity. It turns out that vorticity of the Universe has right-handed chirality.

astro-ph↗

arXiv2012

What do astrophysics and the world's oldest profession have in common?

In the present paper I want to tell of my impressions about the world of research in astrophysics, which I know from close observation. I see with certain pessimism the actual state of astrophysics, as well as of other sciences with similar problems. There are many charms in the profession, as many charms as in love, but not when they are in the service of mercantile aims.

astro-ph↗