4,355 research outputs found
Metal Rich Plasma at the Center Portion of the Cygnus Loop
We observed the center portion of the Cygnus Loop supernova remnant with the
ASCA observatory. The X-ray spectrum of the center portion was significantly
different from that obtained at the North-East (NE) limb. The emission lines
from Si and S were quite strong while those of O and the continuum emission
were similar to those obtained at the NE limb. Based on the spectral analysis,
Si and S emission lines originated from a high-kTe and low ionization plasma
whereas O and most of the continuum emission arose from a low-kTe and high
ionization plasma. We suppose that Si and S emitting gas are present at the
interior of the Loop while O lines and continuum emission mainly arise from the
shell region. Therefore, we subtracted the spectrum of the NE limb from that of
the center. Obtained abundances of Si, S, and Fe were 4 1, 6 2, and
times higher than those of the cosmic abundances,
respectively, and are 40 times richer than those obtained at the NE limb.
These facts strongly support that some of the crude ejecta must be left at the
center portion of the Cygnus Loop. The low abundance of Fe relative to Si and S
suggests a type II SN with a massive progenitor star as the origin of the
Cygnus Loop.Comment: Accepted for Publications of the Astronomical Society of Japan, 40
pages, 12 Postscript figures, uses PASJ95.sty, PASJadd.sty, and psbox.st
Brownian motion on the Sierpinski carpet
We prove that, up to scalar multiples, there exists only one local regular
Dirichlet form on a generalized Sierpinski carpet that is invariant with
respect to the local symmetries of the carpet. Consequently for each such
fractal the law of Brownian motion is uniquely determined and the Laplacian is
well defined
Evolution of Paramagnetic Quasiparticle Excitations Emerged in the High-Field Superconducting Phase of CeCoIn5
We present In NMR measurements in a novel thermodynamic phase of CeCoIn5 in
high magnetic field, where exotic superconductivity coexists with the
incommensurate spin-density wave order. We show that the NMR spectra in this
phase provide direct evidence for the emergence of the spatially distributed
normal quasiparticle regions. The quantitative analysis for the field evolution
of the paramagnetic magnetization and newly-emerged low-energy quasiparticle
density of states is consistent with the nodal plane formation, which is
characterized by an order parameter in the Fulde-Ferrell-Larkin-Ovchinnikov
(FFLO) state. The NMR spectra also suggest that the spatially uniform
spin-density wave is induced in the FFLO phase.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let
Heat kernel estimates for symmetric random walks on a class of fractal graphs and stability under rough isometries,
We examine a class of fractal graphs which arise from a subclass of finitely ramified fractals. The two-sided heat kernel estimates for these graphs are obtained in terms of an effective resistance metric and they are best possible up to constants. If the graph has symmetry, these estimates can be expressed as the usual Gaussian or sub-Gaussian estimates. However, without symmetry, the off-diagonal terms show different decay in different directions. We also discuss the stability of the sub-Gaussian heat kernel estimates under rough isometries
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