2,936 research outputs found
Simulated Galactic methanol maser distribution to constrain Milky Way parameters
Using trigonometric parallaxes and proper motions of masers associated with
massive young stars, the Bar and Spiral Structure Legacy (BeSSeL) survey has
reported the most accurate values of the Galactic parameters so far. The
determination of these parameters with high accuracy has a widespread impact on
Galactic and extragalactic measurements. This research is aimed at establishing
the confidence with which such parameters can be determined. This is relevant
for the data published in the context of the BeSSeL survey collaboration, but
also for future observations, in particular from the Southern Hemisphere. In
addition, some astrophysical properties of the masers can be constrained,
notably the luminosity function. We have simulated the population of
maser-bearing young stars associated with Galactic spiral structure, generating
several samples and comparing them with the observed samples used in the BeSSeL
survey. Consequently, we checked the determination of Galactic parameters for
observational biases introduced by the sample selection. Galactic parameters
obtained by the BeSSeL survey do not seem to be biased by the sample selection
used. In fact, the published error estimates appear to be conservative for most
of the parameters. We show that future BeSSeL data and future observations with
Southern arrays will improve the Galactic parameters estimates and smoothly
reduce their mutual correlation. Moreover, by modeling future parallax data
with larger distance and, thus, greater relative uncertainties for a larger
numbers of sources, we found that parallax-distance biasing is an important
issue. Hence, using fractional parallax uncertainty in the weighting of the
motion data is imperative. Finally, the luminosity function for 6.7 GHz
methanol masers was determined, allowing us to estimate the number of Galactic
methanol masers.Comment: Accepted for publication in A&A. Language edition include
Symbiotic stars in X-rays II: faint sources detected with XMM-Newton and Chandra
We report the detection, with and XMM-, of
faint, soft X-ray emission from four symbiotics stars that were not known to be
X-ray sources. These four object show a -type X-ray spectrum, i.e. their
spectra can be modeled with an absorbed optically thin thermal emission with
temperatures of a few million degrees. Photometric series obtained with the
Optical Monitor on board XMM- from V2416 Sgr and NSV 25735
support the proposed scenario where the X-ray emission is produced in a
shock-heated region inside the symbiotic nebulae.Comment: 5 pages, 1 figure, 2 tables; A&A publishe
Interoperability and Standards: The Way for Innovative Design in Networked Working Environments
Organised by: Cranfield UniversityIn today’s networked economy, strategic business partnerships and outsourcing has become the dominant
paradigm where companies focus on core competencies and skills, as creative design, manufacturing, or
selling. However, achieving seamless interoperability is an ongoing challenge these networks are facing,
due to their distributed and heterogeneous nature. Part of the solution relies on adoption of standards for
design and product data representation, but for sectors predominantly characterized by SMEs, such as the
furniture sector, implementations need to be tailored to reduce costs. This paper recommends a set of best
practices for the fast adoption of the ISO funStep standard modules and presents a framework that enables
the usage of visualization data as a way to reduce costs in manufacturing and electronic catalogue design.Mori Seiki – The Machine Tool Compan
Symbiotic stars in X-rays III: Suzaku observations
We describe the X-ray emission as observed with Suzaku from five symbiotic
stars that we selected for deep Suzaku observations after their initial
detection with ROSAT, ASCA and Swift. We find that the X-ray spectra of all
five sources can be adequately fit with absorbed, optically thin thermal plasma
models, with either single- or multi-temperature plasmas. These models are
compatible with the X-ray emission originating in the boundary layer between an
accretion disk and a white dwarf. The high plasma temperatures of kT keV
for all five targets were greater than expected for colliding winds. Based on
these high temperatures, as well as previous measurements of UV variability and
UV luminosity, and the large amplitude of X-ray flickering in 4 Dra, we
conclude that all five sources are accretion-powered through predominantly
optically thick boundary layers. Our X-ray data allow us to observe a small,
optically thin portion of the emission from these boundary layers. Given the
time between previous observations and these observations, we find that the
intrinsic X-ray flux and the intervening absorbing column can vary by factors
of three or more on a time scale of years. However, the location of the
absorber and the relationship between changes in accretion rate and absorption
are still elusive.Comment: 14 pages, 3 figures and 3 tables. Accepted to published 04/15/2016.
arXiv admin note: substantial text overlap with arXiv:1505.0063
ÂżNeo?-constitucionalismo
El presente trabajo plantea la existencia de coincidencias entre las ideas más
representativas del Neoconstitucionalismo con elementos desarrollados previamente por el
denominado Movimiento del Derecho Libre.This paper discusses the existence of similarities between the most representative
ideas Neoconstitutionalism with items previously developed by the so-called Freirechtsbewegung
Spatial productivity spillovers across Spanish municipalities
Whilst a great deal of e¤ort has been dedicated to identification of agglomeration effects on labour productivity, the measurement of spatial productivity spillovers is a question that has been addressed only occasionally along the New Economic Geography literature. We estimate agglomeration effects, nonetheless conditioned to the possible existence of spatial productivity spillovers across Spanish municipalities in year 2001. To this respect, we find that agglomeration effects are in the same order of magnitude than thoseencountered when measured in the standard way. Further, these agglomeration efects coexist with very strong spatial productivity spillovers in a close neighbourhood of 10 km. Finally, these spatial e¤ects are shown to quickly diminish as distance increases.IV estimation, elevation, spatial externalities, productivity, neighbourhood, Spain
Brief retrospection on Hungarian school atlases
Abstract. The first part of this article is dedicated to the history of Hungarian school atlases to the end of the 1st World War. Although the first maps included in a Hungarian textbook were probably made in 1751, the publication of atlases for schools is dated almost 50 years later, when professor Ézsáiás Budai created his “New School Atlas for elementary pupils” in 1800. This was followed by a long period of 90 years, when the school atlases were mostly translations and adaptations of foreign atlases, the majority of which were made in German-speaking countries. In those years, a school atlas made by a Hungarian astronomer, Antal Vállas, should be highlighted as a prominent independent piece of work. In 1890, a talented cartographer, Manó Kogutowicz founded the Hungarian Geographical Institute, which was the institution responsible for producing school atlases for the different types of schools in Hungary. The professional quality of the school atlases published by his institute was also recognized beyond the Hungarian borders by prizes won in international exhibitions. Kogutowicz laid the foundations of the current Hungarian school cartography: this statement is confirmed in the second part of this article, when three of his school atlases are presented in more detail to give examples of how the pupils were introduced to the basic cartographic and astronomic concepts as well as how different innovative solutions were used on the maps.
</jats:p
The European Map of Job Flows
The European Map of Job Flows (EMJF) is a term used to denote a dataset of meso- and macro-level variables describing different aspect of labour mobility within national labour markets in Europe. In this paper, EMJF is centred on the notion of job “flows”, namely the changes in the level of employment at different breakdowns and levels of aggregation. EMJF is very rich in information content due to the wide variety of possible breakdown of the data and in this sense it is a “map” mostly in the virtual sense, namely, that it is not possible to visualise in the form of geographic maps all the wealth of available information. In terms of its value as a research product and tool, EMJF is mostly an intermediate product in the sense that it is a convenient means to organise the relevant information, which could subsequently be used for different analytical and research purposes. It provides both for cross-sections/snapshots of job flows at different point in time but also it allows their assessment and analysis over longer periods of time. In this sense, EMJF can be widely used for various types of labour-market analysis and research. EMJF’s visual components can also be a convenient tool for policy makers dealing with labour market policies at different level (regional, national or supra-national) in the decision-making process. Here we present a Compilation of a EMJF on the basis of firm-level data In this sense the job flows are built up on the basis of firm-level data for individual countries, following a common methodology. We adopt an approach of establishing such a EMJF on the basis of the AMADEUS dataset developed by the consultancy Bureau van Dijk. The dataset in its most extended version contains balance sheet data and ownership data for almost 14 million firms from 43 different European countries (September 2009 update). For many EU countries the dataset has in principle access to the entire universe of firms which have to report a balance sheet. In terms of countries, the geographic coverage of AMADEUS encompasses information for all the 27 members of the European Union (albeit with different qualities in terms of national coverage) as well as other 16 European countries that complete the geographical and political definition of the continent. Another interesting feature of the database is given by the detailed definition of a firm's location, with data available on the region (NUTS2) and the city in which the firm operates. This project deliverable presents the main results from the final stage of MICRO-DYN work on the EMJF. It discusses the approach to building the EMJF on the basis of AMADEUS data and illustrates the analytical potential of the EMJF as a research tool with a range of Europe-wide analytical exercises. Probably the most important outcome of this research effort is the demonstrated capability to perform meta-analysis at the European level of important labour market characteristics on the basis of firm-level data.job flows, europe, labor market, microdata
- …