206,615 research outputs found
A compiled catalog of rotation measures of radio point sources
We compiled a catalog of Faraday rotation measures (RMs) for 4553
extragalactic radio point sources ublished in literature. These RMs were
derived from multi-frequency polarization observations. The RM data are
compared to those in the NRAO VLA Sky Survey (NVSS) RM catalog. We reveal a
systematic uncertainty of about \,rad~m in the NVSS RM
catalog. The Galactic foreground RM is calculated through a weighted averaging
method by using the compiled RM catalog together with the NVSS RM catalog, with
careful consideration of uncertainties in the RM data. The data from the
catalog and the interface for the Galactic foreground RM calculations are
publicly available on the webpage: http://zmtt.bao.ac.cn/RM/.Comment: 17 pages, 8 figures. Published already, at
http://www.raa-journal.org/raa/index.php/raa/article/view/171
Shear stress relaxation and ensemble transformation of shear stress autocorrelation functions revisited
We revisit the relation between the shear stress relaxation modulus ,
computed at finite shear strain , and the shear stress
autocorrelation functions and computed,
respectively, at imposed strain and mean stress . Focusing on
permanent isotropic spring networks it is shown theoretically and
computationally that in general
for with being the static equilibrium shear modulus.
and thus must become different for solids and it is impossible
to obtain alone from as often assumed. We comment
briefly on self-assembled transient networks where must vanish for
a finite scission-recombination frequency . We argue that should reveal an intermediate plateau set by the
shear modulus of the quenched network.Comment: 8 pages, 4 figure
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