Eine unheilige Allianz: Das Schweizer Bürgerrecht zwischen kommunaler Rechtstradition, bundesstaatlichem Laisser-faire and ethnisch-nationaler Fremdenabwehr 1848-1933

Der Beitrag zeichnet die Entwicklung des föderalistischen Schweizer Bürgerrechts zwischen der Bundesstaatsgründung im Jahr 1848 und der Verankerung einer restriktiven Einbürgerungs- und Niederlassungspolitik in der Zwischenkriegszeit nach. Ausgehend von der schwierigen staatsbürgerlichen Integration der ausländischen Wohnbevölkerung in Geschichte und Gegenwart der Schweiz fragt die Autorin nach den Ursachen für die Gewährung und Verweigerung des Schweizer Bürgerrechts. Dabei wird deutlich, dass sich die Entwicklung und Ausprägung des Zugangs zum Schweizer Bürgerrecht nicht allein auf Vorstellungen von der schweizerischen Nation oder auf staatliche Interessen reduzieren lassen. Vielmehr waren sie Ergebnis eines permanenten politischen Aushandlungs- und Koordinationsprozesses zwischen Bund, Kantonen und Gemeinden: Das Gemeindebürgerrecht bildete aufgrund seiner armenrechtlichen Bedeutung bis weit ins 20. Jahrhundert hinein das Nadelöhr für Einbürgerungen. Im Gegensatz dazu versuchten der Bund und einzelne Kantone wie Zürich, Basel und Genf die seit den 1880er Jahren stark angestiegene Zahl der ausländischen Wohnbevölkerung durch die Liberalisierung der Einbürgerung zu verringern. Der Ausbruch des Ersten Weltkriegs setzte diesen Bestrebungen ein Ende. Im Zuge des Aufstiegs einer »neuen Rechten« seit 1900, der Gründung der Eidgenössischen Fremdenpolizei im Jahr 1917 und der Institutionalisierung der behördlichen »Überfremdungsbekämpfung« wurde das schweizerische Staatsangehörigkeitsrecht nachträglich ethnisiert. Die kulturelle »Assimilation« an die »schweizerische Eigenart« galt nun als Voraussetzung dafür, um Schweizer Bürger zu werden. Dabei verband sich die neue bundesstaatliche Fremdenabwehr mit der traditionell restriktiven Politik der Gemeinden, eine unheilige Allianz, die erst in den 1980er Jahren aufzubrechen begann.The article traces the development of the federal structure of Swiss citizenship between the founding of the federal state in 1948 and the entrenchment of a restrictive naturalisation and establishment policy in the interwar period. Considering the difficult integration of the foreign residents through naturalisation in the past and present in Switzerland, the author examines the causes for the granting and refusal of Swiss citizenship. She shows that the development of and arrangements for access to Swiss citizenship cannot be reduced only to notions about the Swiss nation or national interests. They are the result of a permanent process of political negotiation and coordination between the federation, cantons, and local authorities: owing to its importance in social assistance matters, local citizenship constituted an impediment to naturalisation until well into the 20th century. In contrast, the federation and certain cantons like Zurich, Basle, and Geneva had sought since the 1880s to reduce the strongly increasing number of foreign residents by liberalising naturalisation. The outbreak of the Second World War put an end to these endeavours. With the rise of a “new right” since 1900, the setting up of the Central Office of the Police for Foreigners in 1917, and the institutionalisation of the authorities’ “fight against foreign infiltration,” Swiss nationality law became ethnicized. Cultural “assimilation” into the “particularity of Swiss society” was now regarded as a precondition for becoming a Swiss citizen. The new federal rejection of foreigners thus joined with the traditionally restrictive policy of local authorities in an unholy alliance that began to breach only in the 1980s

The Explosive Yields Produced by the First Generation of Core Collapse Supernovae and the Chemical Composition of Extremely Metal Poor Stars

We present a detailed comparison between an extended set of elemental abundances observed in some of the most metal poor stars presently known and the ejecta produced by a generation of primordial core collapse supernovae. We used five stars which form our initial database and define a "template" ultra metal poor star which is then compared to the theoretical predictions. Our main findings are as follows: a) the fit to [Si/Mg] and [Ca/Mg] of these very metal poor stars seems to favor the presence of a rather large C abundance at the end of the central He burning; in a classical scenario in which the border of the convective core is strictly determined by the Schwarzschild criterion, such a large C abundance would imply a rather low C12(alpha,gamma)O16 reaction rate; b) a low C abundance left by the central He burning would imply a low [Al/Mg] (<-1.2 dex) independently on the initial mass of the exploding star while a rather large C abundance would produce such a low [Al/Mg] only for the most massive stellar model; c) at variance with current beliefs that it is difficult to interpret the observed overabundance of [Co/Fe], we find that a mildly large C abundance in the He exhausted core (well within the present range of uncertainty) easily and naturally allows a very good fit to [Co/Fe]; d) our yields allow a reasonable fit to 8 out of the 11 available elemental abundances; e) within the present grid of models it is not possible to find a good match of the remaining three elements, Ti, Cr and Ni (even for an arbitrary choice of the mass cut); f) the adoption of other yields available in the literature does not improve the fit; g) since no mass in our grid provides a satisfactory fit to these three elements, even an arbitrary choice of the initial mass function would not improve their fit.Comment: 30 pages, 8 figures, 8 tables. Accepted for publication on Ap

Isolated Star Formation: A Compact HII Region in the Virgo Cluster

We report on the discovery of an isolated, compact HII region in the Virgo cluster. The object is located in the diffuse outer halo of NGC 4388, or could possibly be in intracluster space. Star formation can thus take place far outside the main star forming regions of galaxies. This object is powered by a small starburst with an estimated mass of \sim 400\msun and age of \sim 3\myr. From a total sample of 17 HII region candidates, the present rate of isolated star formation estimated in our Virgo field is small, \sim 10^{-6} Msun arcmin}^{-2} yr^{-1}. However, this mode of star formation might have been more important at higher redshifts and be responsible for a fraction of the observed intracluster stars and total cluster metal production. This object is relevant also for distance determinations with the planetary nebula luminosity function from emission line surveys, for high-velocity clouds and the in situ origin of B stars in the Galactic halo, and for local enrichment of the intracluster gas by Type II supernovae.Comment: 5 pages, LaTeX, 1 figure. ApJ Letters, in press (scheduled Dec 1, 2002

Constraints on the Astrophysical Nature of r-Process Nucleosynthesis Sites from Inhomogeneous Chemical Evolution Models

We present a detailed inhomogeneous chemical evolution study that considers for the first-time neutron star mergers as major r-process sources, and compare this scenario with the ones in which lower-mass (in the range 8-10 M⊙) or higher-mass core-collapse supernovae (with masses ≥20 M⊙) act as dominant r-process sites. We conclude that it is not possible at present to distinguish between the lower-mass and higher-mass supernovae scenarios within the framework of inhomogeneous chemical evolution. However, neutron-star mergers seem to be ruled out as the dominant r-process source, since their low rates of occurrence would lead to r-process enrichment that is not consistent with observation

Stochastic chemical enrichment in metal-poor systems II. Abundance ratios and scatter

A stochastic model of the chemical enrichment of metal-poor systems by core-collapse supernovae is used to study the scatter in stellar abundance ratios. The resulting scatter in abundance ratios, e.g. as functions of the overall metallicity, is demonstrated to be crucially dependent on the as yet uncertain supernovae yields. The observed abundance ratios and their scatters therefore have diagnostic power as regards the yields. The relatively small star-to-star scatter observed in many chemical abundance ratios, e.g. by Cayrel et al. (2004) for stars down to [Fe/H] = -4, is tentatively explained by the averaging of a large number of contributing supernovae and by the cosmic selection effects favoring contributions from supernovae in a certain mass range for the most metal-poor stars. The scatter in observed abundances of alpha-elements is understood in terms of observational errors only, while additional spread in yields or sites of nucleosynthesis may affect the odd-even elements Na and Al. For the iron-group elements we find systematically too high predicted Cr/Fe and Cr/Mg ratios, as well as differences between the different sets of yields, both in terms of predicted abundance ratios and scatter. The semi-empirical yields recently suggested by Francois et al. (2004) are found to lead to scatter in abundance ratios significantly greater than observed, when applied in the inhomogeneous models. "Spurs", very narrow sequences in abundance-ratio diagrams, may disclose a single-supernova origin of the elements of the stars on the sequence. Verification of the existence of such features, called single supernova sequences (SSSs), is challenging. This will require samples of several hundred stars with abundance ratios observed to accuracies of 0.05 dex or better.Comment: 19 pages, 20 figures, accepted for publication in Astronomy & Astrophysic

Deriving the Metallicity Distribution Function of Galactic Systems

The chemical evolution of the Milky Way is investigated using a dual-phase metal-enriched infall model in which primordial gas fuels the earliest epoch of star formation, followed by the ongoing formation of stars from newly accreted gas. The latest metallicity distribution of local K-dwarfs is reproduced by this model, which allows the Galactic thin disk to form from slightly metal-enriched gas with alpha-element enhancement. Our model predicts ages for the stellar halo and thin disk of 12.5 and 7.4 Gyr, respectively, in agreement with empirically determined values. The model presented in this paper is compared with a similar dual-phase infall model from Chiappini et al. (2001). We discuss a degeneracy that enables both models to recover the K-dwarf metallicity distribution while yielding different star formation histories. The metallicity distribution function (MDF) of K-dwarfs is proposed to be more directly comparable to chemical evolution model results than the G-dwarf distribution because lower mass K-dwarfs are less susceptible to stellar evolutionary effects. The K-dwarf MDF should consequently be a better probe of star formation history and provide a stronger constraint to chemical evolution models than the widely used G-dwarf MDF. The corrections that should be applied to a G-dwarf MDF are quantified for the case of the outer halo of NGC 5128.Comment: 16 pages, 5 figures, accepted for publication in PASA (Publications of the Astronomical Society of Australia

Mixing Time Scales in a Supernova-Driven Interstellar Medium

We study the mixing of chemical species in the interstellar medium (ISM). Recent observations suggest that the distribution of species such as deuterium in the ISM may be far from homogeneous. This raises the question of how long it takes for inhomogeneities to be erased in the ISM, and how this depends on the length scale of the inhomogeneities. We added a tracer field to the three-dimensional, supernova-driven ISM model of Avillez (2000) to study mixing and dispersal in kiloparsec-scale simulations of the ISM with different supernova (SN) rates and different inhomogeneity length scales. We find several surprising results. Classical mixing length theory fails to predict the very weak dependence of mixing time on length scale that we find on scales of 25--500 pc. Derived diffusion coefficients increase exponentially with time, rather than remaining constant. The variance of composition declines exponentially, with a time constant of tens of Myr, so that large differences fade faster than small ones. The time constant depends on the inverse square root of the supernova rate. One major reason for these results is that even with numerical diffusion exceeding physical values, gas does not mix quickly between hot and cold regions.Comment: 23 pages, 14 figures that include 7 simulation images and 19 plots, accepted for publication at Ap

The Microstructure of Pyrite Blackening in Fossil Shells

The Waynesville formation is part of the stratigraphic succession of Indiana bedrock which allows us to look back on environmental conditions during the late Ordovician period, 450 million years ago. Due in part to a fossil record which is overwhelminlgly dominated by a single species, the Waynesville formation functions as an outdoor labratory illustrating various preservation processes operating on directly comparable shells. Shell blackening during preservation has been a particular point of interest. Based on the correlation of shell blackening with occurrences of shell fragmentation and abrasion in large brachiopods, the shell blackening seen in Upper Ordovician (Cincinnatian) brachiopods has previously been identified as a sign of long residence on the sea floor, and has been attributed to the accumulation of iron sulfides and organics in microborings. This in turn suggests extremely low oxygen microenvironments within shells. The results of our studies are broadly consistent with prior hypotheses.http://opus.ipfw.edu/stu_symp2015/1055/thumbnail.jp

The early phases of Milky Way's chemical evolution

The earliest phases of the chemical evolution of our Galaxy are analysed in the light of the recent VLT results (concerning abundance patterns in the most metal-poor stars of the Galactic halo) and of stellar nucleosynthesis calculations. It is argued that: 1) the unexpected abundance patterns observed in Pop. II stars are not the imprints of an early generation of supermassive Pop. III stars; 2) among the various suggestions made to exlain the observed abundance patterns, nucleosynthesis in asymmetric supernova explosions appears most promising. In the latter case, an indirect correlation between asymmetry and metallicity is suggested by the data. Finally, the VLT data confirm two old ``puzzles'': the existence of primary N early in Galaxy's evolution (which constrains the mixing of protons with He-burning products in massive stars) and the absence of dispersion in abundance ratios, at least up to the Fe peak, in the early Galaxy (which bears on the timescales of homogeneisation of the interstellar medium, but also on yield variations among massive stars).Comment: 10 pages, 4 figures, Review talk in Nuclei in the Cosmos VIII (Eds. L. Buchmann et al.) to appear in NuclPhys