Related papers: Spiral Galaxies as Chiral Objects?
Three-dimensional orientational order in systems whose ground states possess non-zero, chiral gradients typically exhibits line-like structures or defects: $\lambda$ lines in cholesterics or Skyrmion tubes in ferromagnets for example. Here…
Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively levorotatory (L) amino acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The mechanism…
We present evidence that all galaxies, of any Hubble type and luminosity, bear the kinematical signature of a mass component distributed differently from the luminous matter. We review and/or derive the DM halo properties of galaxies of…
Passive spiral galaxies -- unusual galaxies with spiral morphology without any sign of on-going star formation -- have recently been discovered to exist preferentially in cluster infalling regions (at about the virial radius, or at a local…
We review the topic of rotation curves of spiral galaxies emphasizing the standard interpretation as evidence for the existence of dark matter halos. Galaxies other than spirals and late-type dwarfs may also possess great amounts of dark…
The flow of time moves in one direction in any spatial position and orientation in this universe. Chiral objects, which lack mirror symmetry, retain their chirality regardless of their position or orientation. Despite being seemingly…
Galaxies represent the visible fabric of the Universe and there has been considerable progress recently in both observational and theoretical studies. The underlying goal is to understand the present-day diversity of galaxy forms, masses…
Deep surveys conducted during the past decades have shown that galaxies in the distant universe are generally of more irregular shapes, and are disky in appearance and in their star formation rate, compared to galaxies in similar…
We show that simple models of the chemical and spectrophotometric evolution of galaxies can be used to explore the properties of present-day galaxies and especially the causes of the observed variety among disc galaxies. We focus on the…
In this paper, we look to analyse the spiral features of grand-design, multiarmed, and flocculent spiral galaxies using deep optical imaging from DESI Legacy Imaging Surveys. We explore the resulting distributions of various characteristics…
The environmental dependencies of the characteristics of spiral galaxy rotation curves are studied in this work. We use our large, homogeneously collected sample of 510 cluster spiral galaxy rotation curves to test the claim that the shape…
Chirality refers to the asymmetry of objects that cannot be superimposed on their mirror image. It is a concept that exists in various scientific fields and has profound consequences. Although these are perhaps most widely recognized within…
Globular clusters in galaxies have a mutual feedback with the environment, which is tuned by their dynamical evolution. This feedback may be the explanation of various features of both the globular cluster system and the host galaxy.…
Beginning with a geometric motivation for dark matter going back to the axioms of general relativity, we show how scalar field dark matter, which naturally forms dark matter density waves due to its wave nature, may cause the observed…
In chemistry and biochemistry, chirality represents the structural asymmetry characterized by non-superimposable mirror images for a material like DNA. In physics, however, chirality commonly refers to the spin-momentum locking of a…
Chandra is revolutionising our understanding of the X-ray emission from spiral galaxies. Before Chandra, detailed extragalactic studies were limited to Local Group galaxies. We are now able to obtain detailed inventories of sources in…
The properties of universes are explored that are entirely in the interior of black holes in another universe, a `mother universe'. It is argued that these models offer a paradigm that may shed a new light on old cosmological problems. The…
Globular clusters are large and dense agglomerate of stars. At variance with smaller clusters of stars, they exhibit signs of some chemical evolution. At least for this reason, they are intermediate between open clusters and massive objects…
The fundamental issues of symmetry related to chirality are discussed and applied to simple situations relevant to liquid crystals. We show that any chiral measure of a geometric object is a pseudoscalar (invariant under proper rotations…
Globular clusters are collisional systems, meaning that the stars inside them interact on timescales much shorter than the age of the Universe. These frequent interactions transfer energy between stars and set up observable trends that tell…