16 research outputs found
Stereotactic Transplantation of Foetal Ventral Mesencephalic Cells: Cuban Experience from Five Patients with Idiopathic Parkinson's Disease
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
A Search for Extended Ultraviolet Disk (XUV-disk) Galaxies in the Local Universe
We have initiated a search for extended ultraviolet disk (XUV-disk) galaxies
in the local universe. Herein, we compare GALEX UV and visible--NIR images of
189 nearby (D40 Mpc) S0--Sm galaxies included in the GALEX Atlas of Nearby
Galaxies and present the first catalogue of XUV-disk galaxies. We find that
XUV-disk galaxies are surprisingly common but have varied relative (UV/optical)
extent and morphology. Type~1 objects (\ga20% incidence) have structured,
UV-bright/optically-faint emission features in the outer disk, beyond the
traditional star formation threshold. Type~2 XUV-disk galaxies (10%
incidence) exhibit an exceptionally large,
UV-bright/optically-low-surface-brightness (LSB) zone having blue
outside the effective extent of the inner, older stellar population, but not
reaching extreme galactocentric distance. If the activity occuring in XUV-disks
is episodic, a higher fraction of present-day spirals could be influenced by
such outer disk star formation. Type~1 disks are associated with spirals of all
types, whereas Type~2 XUV-disks are predominantly found in late-type spirals.
Type~2 XUV-disks are forming stars quickly enough to double their [presently
low] stellar mass in the next Gyr (assuming a constant SF rate). XUV-disk
galaxies of both types are systematically more gas-rich than the general galaxy
population. Minor external perturbation may stimulate XUV-disk incidence, at
least for Type~1 objects. XUV-disks are the most actively evolving galaxies
growing via inside-out disk formation in the current epoch, and may constitute
a segment of the galaxy population experiencing significant, continued gas
accretion from the intergalactic medium or neighboring objects.Comment: 83 pages, 16 figures, 2 tables. Appearing in the GALEX special issue
of ApJS. (A version with high quality figures and proof corrections can be
found at http://www.journals.uchicago.edu/toc/apjs/173/2