1,021 research outputs found
Probing the Structure of Jet Driven Core-Collapse Supernova and Long Gamma Ray Burst Progenitors with High Energy Neutrinos
Times of arrival of high energy neutrinos encode information about their
sources. We demonstrate that the energy-dependence of the onset time of
neutrino emission in advancing relativistic jets can be used to extract
important information about the supernova/gamma-ray burst progenitor structure.
We examine this energy and time dependence for different supernova and
gamma-ray burst progenitors, including red and blue supergiants, helium cores,
Wolf-Rayet stars, and chemically homogeneous stars, with a variety of masses
and metallicities. For choked jets, we calculate the cutoff of observable
neutrino energies depending on the radius at which the jet is stalled. Further,
we exhibit how such energy and time dependence may be used to identify and
differentiate between progenitors, with as few as one or two observed events,
under favorable conditions
NGC 7789: An Open Cluster Case Study
We have obtained high-resolution spectra of 32 giants in the open cluster NGC
7789 using the Wisconsin-Indiana-Yale-NOAO Hydra spectrograph. We explore
differences in atmospheric parameters and elemental abundances caused by the
use of the linelist developed for the Gaia-ESO Survey (GES) compared to one
based on Arcturus used in our previous work. [Fe/H] values decrease when using
the GES linelist instead of the Arcturus-based linelist; these differences are
probably driven by systematically lower (~ -0.1 dex) GES surface gravities.
Using the GES linelist we determine abundances for 10 elements - Fe, Mg, Si,
Ca, Ti, Na, Ni, Zr, Ba, and La. We find the cluster's average metallicity
[Fe/H] = 0.03 +/- 0.07 dex, in good agreement with literature values, and a
lower [Mg/Fe] abundance than has been reported before for this cluster (0.11
+/- 0.05 dex). We also find the neutron-capture element barium to be highly
enhanced - [Ba/Fe] = +0.48 +/- 0.08 - and disparate from cluster measurements
of neutron-capture elements La and Zr (-0.08 +/- 0.05 and 0.08 +/- 0.08,
respectively). This is in accordance with recent discoveries of supersolar Ba
enhancement in young clusters along with more modest enhancement of other
neutron-capture elements formed in similar environments.Comment: 15 pages, 9 figures, Table 1 typo fixe
Erdö, Péter, Egyhäzjog (Szent István kézikönyvek 7), Szent István Társulat, Budapest 2003, 878 pp.
Seasonal changes in brain serotonin transporter binding in short 5-HTTLPR-allele carriers but not in long-allele homozygotes
Several findings suggest seasonal variations in the serotonin (5-HT) system. We sought evidence for seasonal variation in the serotonin transporter (5-HTT). We found that length of daylight time in minutes correlates negatively with 5-HTT binding in the putamen and the caudate, with a similar tendency in the thalamus, but no such association in the midbrain. In the putamen, an anatomical region with a dense serotonin innervation that is implicated in processing of aversive stimuli, we found a significant gene*daylight effect with a negative correlation between the 5-HTT binding and daylight time in carriers of the short 5-HTTLPR allele, but not in carriers of the long allele. The neurobiological endophenotype identified here directly links activation studies, showing responses on the neural circuit level, with dynamic changes in transporter expression measured in vivo
Towards understanding the ordering behavior of hard needles: New analytical solutions in one dimension
We re-examine the ordering behavior of a one-dimensional fluid of freely
rotating hard needles, where the centers of mass of the particles are
restricted to a line. Analytical equations are obtained for the equation of
state, order parameter and orientational correlation functions using the
transfer-matrix method if some simplifying assumptions are applied for either
the orientational freedom or the contact distance between two needles. The
two-state Zwanzig model accounts for the orientational ordering, but it
produces unphysical pressure at high densities and there is no orientational
correlation. The four-state Zwanzig model gives reasonable results for
orientational correlation function, but the pressure is still poorly
represented at high densities. In the continuum limit, apart from the
orientational correlation length it is managed to reproduce all relevant bulk
properties of the hard needles using an approximate formula for the contact
distance. The results show that the orientational correlation length diverges
at zero and infinite pressures. The high density behavior of needles is not
resolved.Comment: 21 pages, 3 figure
Opportunity to Test non-Newtonian Gravity Using Interferometric Sensors with Dynamic Gravity Field Generators
We present an experimental opportunity for the future to measure possible
violations to Newton's 1/r^2 law in the 0.1-10 meter range using Dynamic
gravity Field Generators (DFG) and taking advantage of the exceptional
sensitivity of modern interferometric techniques. The placement of a DFG in
proximity to one of the interferometer's suspended test masses generates a
change in the local gravitational field that can be measured at a high signal
to noise ratio. The use of multiple DFGs in a null experiment configuration
allows to test composition independent non-Newtonian gravity significantly
beyond the present limits. Advanced and third-generation gravitational-wave
detectors are representing the state-of-the-art in interferometric distance
measurement today, therefore we illustrate the method through their sensitivity
to emphasize the possible scientific reach. Nevertheless, it is expected that
due to the technical details of gravitational-wave detectors, DFGs shall likely
require dedicated custom configured interferometry. However, the sensitivity
measure we derive is a solid baseline indicating that it is feasible to
consider probing orders of magnitude into the pristine parameter well beyond
the present experimental limits significantly cutting into the theoretical
parameter space.Comment: 9 pages, 6 figures; Physical Review D, vol. 84, Issue 8, id. 08200
Isolation of myo-inositol-1-phosphate synthetase from wild type and an inositol-less variant Neurospora crassa
Isolation of myo-inositol-1-phosphate synthetase from wild type and an inositol-less varian
Transition temperature and the equation of state from lattice QCD, Wuppertal-Budapest results
The QCD transition is studied on lattices up to . The chiral
condensate is presented as a function of the temperature, and the corresponding
transition temperature is extracted. The equation of state is determined on
lattices with and at some temperature values with . The
pressure and the trace anomaly are presented as functions of the temperature in
the range 100 ...1000 MeV . Using the same configurations we determine the
continuum extrapolated phase diagram of QCD on the plane for small to
moderate chemical potentials. Two transition lines are defined with two
quantities, the chiral condensate and the strange quark number susceptibility.Comment: 4 pages, 2 figures, Proceedings for Quark Matter 201
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