29 research outputs found
Influence of diabetes on natriuretic peptide thresholds in screening for Stage B heart failure
Actively Star Forming Elliptical Galaxies at Low Redshifts in the Sloan Digital Sky Survey
We report discovery of actively star forming elliptical galaxies in a
morphologically classified sample of bright galaxies at a low redshift obtained
from the Sloan Digital Sky Survey. The emission lines of these galaxies do not
show the characteristics of active galactic nuclei, and thus their strong
H emission is ascribed to star formation with a rate nearly as high as
that is seen in typical late spiral galaxies. This is taken as evidence against
the traditional view that all elliptical galaxies formed early and now evolve
only passively. The frequency of such star forming elliptical galaxies is a few
tenths of a percent in the sample, but increases to 3% if we include active S0
galaxies. We may identify these galaxies as probable progenitors of so-called
E+A galaxies that show the strong Balmer absorption feature of A stars
superimposed on an old star population. The approximate match of the abundance
of active elliptical plus S0 galaxies with that of E+A galaxies indicates that
the duration of such late star formation episodes is of the order of \gsim 1
Gyr. If we interpret these galaxies as new additions to the early-type galaxy
population, and if we assume a power law for their number evolution, the
abundance of early-type galaxies at is about 30% less than that at .Comment: Accepted for publication in Astrophys. J. Letter
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Roadmap on quantum nanotechnologies
Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a view to what the future holds. Materials and devices with nanoscale features are used for quantum metrology and sensing, as building blocks for quantum computing, and as sources and detectors for quantum communication. They enable explorations of quantum behaviour and unconventional states in nano- and opto-mechanical systems, low-dimensional systems, molecular devices, nano-plasmonics, quantum electrodynamics, scanning tunnelling microscopy, and more. This rapidly expanding intersection of nanotechnology and quantum science/technology is mutually beneficial to both fields, laying claim to some of the most exciting scientific leaps of the last decade, with more on the horizon