1,180 research outputs found
The GLAS editing procedures for the FGGE level II-B data collected during SOP-1 and 2
The modifications made to the FGGE Level II-b data are discussed and the FORTRAN program developed to perform the modifications is described. It is suggested that the edited database is the most accurate one available for FGGE SOP-1 and 2
Objective analysis of observational data from the FGGE observing systems
An objective analysis procedure for updating the GLAS second and fourth order general atmospheric circulation models using observational data from the first GARP global experiment is described. The objective analysis procedure is based on a successive corrections method and the model is updated in a data assimilation cycle. Preparation of the observational data for analysis and the objective analysis scheme are described. The organization of the program and description of the required data sets are presented. The program logic and detailed descriptions of each subroutine are given
Three-dimensional simulations of the interaction between Type Ia supernova ejecta and their main sequence companions
The identity of the progenitor systems of SNe Ia is still uncertain. In the
single-degenerate (SD) scenario, the interaction between the SN blast wave and
the outer layers of a main sequence (MS) companion star strips off H-rich
material which is then mixed into the ejecta. Strong contamination of the SN
ejecta with stripped material could lead to a conflict with observations of SNe
Ia. This constrains the SD progenitor model. In this work, our previous
simulations based on simplified progenitor donor stars have been updated by
adopting more realistic progenitor-system models that result from fully
detailed, state-of-the-art binary evolution calculations. We use Eggleton's
stellar evolution code including the optically thick accretion wind model and
the possibility of the effects of accretion disk instabilities to obtain
realistic models of companions for different progenitor systems. The impact of
the SN blast wave on these companion stars is followed in three-dimensional
hydrodynamic simulations employing the SPH code GADGET3. We find that the
stripped masses range from 0.11 to 0.18 M_sun. The kick velocity is between 51
and 105 km/s. We find that the stripped mass and kick velocity depend on the
ratio of the orbital separation to the radius of a companion. They can be
fitted by a power law for a given companion model. However, the structure of
the companion star is also important for the amount of stripped material. With
more realistic companion star models than in previous studies, our simulations
show that the H masses stripped from companions are inconsistent with the best
observational limits (< 0.01 M_sun) derived from nebular spectra. However, a
rigorous forward modeling based on impact simulations with radiation transfer
is required to reliably predict observable signatures of the stripped H and to
conclusively assess the viability of the considered SN Ia progenitor scenario.Comment: 14 pages, 13 figures, accepted for publication by A&
Deuteron Spin Structure Functions at Small Bjorken-x
We investigate polarized deuteron structure functions at small values of the
Bjorken variable, x < 0.1. In this region contributions from the coherent
interaction of diffractively excited hadronic states with both nucleons become
important. A proper treatment of this process requires an extension of the
Glauber-Gribov multiple scattering theory to include spin degrees of freedom.
In the kinematic domain of current fixed target experiments we observe that
shadowing effects in g_1d are approximately twice as large as for the
unpolarized structure function F_2d. Furthermore at x < 0.1 the tensor
structure function b_1 is found to receive significant contributions from
coherent double scattering.Comment: 30 pages, Revtex, include discussion on t-dependence of diffractive
production processes, to appear in Phys. Rev.
Documentation of the GLAS fourth order general calculation model. Volume 3: Vectorized code for the Cyber 205
Volume 3 of a 3-volume technical memoranda which contains documentation of the GLAS fourth order genera circulation model is presented. The volume contains the CYBER 205 scalar and vector codes of the model, list of variables, and cross references. A dictionary of FORTRAN variables used in the Scalar Version, and listings of the FORTRAN Code compiled with the C-option, are included. Cross reference maps of local variables are included for each subroutine
Documentation of the GLAS fourth order general circulation model. Volume 1: Model documentation
The volume 1, of a 3 volume technical memoranda which contains a documentation of the GLAS Fourth Order General Circulation Model is presented. Volume 1 contains the documentation, description of the stratospheric/tropospheric extension, user's guide, climatological boundary data, and some climate simulation studies
Documentation of the GLAS fourth order general circulation model. Volume 2: Scalar code
Volume 2, of a 3 volume technical memoranda contains a detailed documentation of the GLAS fourth order general circulation model. Volume 2 contains the CYBER 205 scalar and vector codes of the model, list of variables, and cross references. A variable name dictionary for the scalar code, and code listings are outlined
QCD Aspects of Hadron Physics
Several topics in hadron physics at different scales of resolution are
discussed. First, deep-inelastic scattering from nucleons and nuclei is viewed
in a light-cone coordinate space picture. Then the smooth transition from
parton to hadron degrees of freedom is demonstrated by using a generalized
Q^2-dependent polarizabilities of the nucleon. Turning to low energy QCD we
summarize recent developments related to the role of strange quarks in Chiral
SU(3) Dynamics, a non-perturbative coupled channel approach to hadronic
processes. Finally we elaborate on a unification of QCD Sum Rules with aspects
of spontaneous chiral symmetry breaking in the analysis of quark-antiquark
excitations of the condensed QCD vacuum and in nuclear matter.Comment: 12 pages, 6 figures. Dedicated to Koichi Yazaki on the occasion of
his 60th birthday; invited talk presented at the KEK-Tanashi Symposium on
Physics of Hadrons and Nuclei, Tokyo, December 14-17, 199
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