3,461 research outputs found
U.S. securities markets and the banking system, 1790-1840 - commentary
Banks and banking - History ; Stock market ; Securities ; Bank stocks
The harmonic power spectrum of the soft X-ray background I. The data analysis
Fluctuations of the soft X-ray background are investigated using harmonic
analysis. A section of the ROSAT All-Sky Survey around the north galactic pole
is used. The flux distribution is expanded into a set of harmonic functions and
the power spectrum is determined. Several subsamples of the RASS have been used
and the spectra for different regions and energies are presented. The effects
of the data binning in pixels are assessed and taken into account. The spectra
of the analyzed samples reflect both small scale effects generated by strong
discrete sources and the large scale gradients of the XRB distribution. Our
results show that the power spectrum technique can be effectively used to
investigate anisotropy of the XRB at various scales. This statistics will
become a useful tool in the investigation of various XRB components.Comment: 12 pages, A&A accepte
Radiation effects on silicon Final report, Jun. 1, 1964 - May 31, 1965
Radiation effects on silicon - degradation of carrier lifetime in N and P type silicon samples exposed to 30 MeV electron irradiatio
Missing baryons and the soft X-ray background
The X-ray background intensity around Lick count galaxies and rich clusters
of galaxies is investigated in three ROSAT energy bands. It is found that the
X-ray enhancements surrounding concentrations of galaxies exhibit significantly
softer spectrum than the standard cluster emission and the average
extragalactic background. The diffuse soft emission accompanying the galaxies
is consistent with the thermal emission of the hot gas postulated first by the
Cen & Ostriker hydrodynamic simulations. Our estimates of the gas temperature -
although subject to large uncertainties - averaged over several Mpc scales are
below 1 keV, which is substantially below the temperature of the intra-cluster
gas, but consistent with temperatures predicted for the local intergalactic
medium. It is pointed out that the planned ROSITA mission would be essential
for our understanding of the diffuse thermal component of the background.Comment: AA accepted, 6 pages, incl. 4 figure
Local Interstellar Medium Kinematics towards the Southern Coalsack and Chamaeleon-Musca dark clouds
The results of a spectroscopic programme aiming to investigate the kinematics
of the local interstellar medium components towards the Southern Coalsack and
Chamaeleon-Musca dark clouds are presented. The analysis is based upon
high-resolution (R ~ 60,000) spectra of the insterstellar NaI D absorption
lines towards 63 B-type stars (d < 500 pc) selected to cover these clouds and
the connecting area defined by the Galactic coordinates: 308 > l > 294 and -22
< b < 5. The radial velocities, column densities, velocity dispersions, colour
excess and photometric distances to the stars are used to understand the
kinematics and distribution of the interstellar cloud components. The analysis
indicates that the interstellar gas is distributed in two extended sheet-like
structures permeating the whole area, one at d < 60 pc and another around
120-150 pc from the Sun. The dust and gas feature around 120-150 pc seem to be
part of an extended large scale feature of similar kinematic properties,
supposedly identified with the interaction zone of the Local and Loop I
bubbles.Comment: 19 pages, accepted for MNRA
The XMM-Newton EPIC Background and the production of Background Blank Sky Event Files
We describe in detail the nature of XMM-Newton EPIC background and its
various complex components, summarising the new findings of the XMM-Newton EPIC
background working group, and provide XMM-Newton background blank sky event
files for use in the data analysis of diffuse and extended sources. Blank sky
event file data sets are produced from the stacking of data, taken from 189
observations resulting from the Second XMM-Newton Serendipitous Source
Catalogue (2XMMp) reprocessing. The data underwent several filtering steps,
using a revised and improved method over previous work, which we describe in
detail. We investigate several properties of the final blank sky data sets. The
user is directed to the location of the final data sets. There is a final data
set for each EPIC instrument-filter-mode combination.Comment: Paper accepted by A&A 22 December 2006. 14 pages, 8 figures. Paper
can also be found at http://www.star.le.ac.uk/~jac48/publications
The Anatomy of a Residential Mortgage Crisis: A Look Back to the 1930s
Looking back to the 1930s provides the opportunity to examine one severe mortgage crisis as we live through another. This paper examines the development of the residential mortgage market during the 1920s, the institutional disruptions that occurred in the 1930s and the policy response of federal and state governments. The crisis reshaped the structure and development of the residential mortgage market and led to a postwar system in which portfolio lenders dominated both local and interregional markets. Some pre-1930 innovationsâmortgage insurance and high-leverage, affordable loansâwere written into federal programs and became part of the new system. But early experiments and proposals for securitization did not survive the 1930s and the implementation of this innovation was delayed for forty years.
The American Compound
Scarcely addressed in the literature, the compound has gained broad recognition in the American vernacular as a spatially separate and unique form of settlement. Although largely viewed as a fringe development, compounds have deep roots in the historical development of the American landscape
Radiation effects on silicon second quarterly progress report, sep. 1 - nov. 30, 1964
Electron spin resonance measurements on P-doped silicon - vacancy phosphorus defec
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