A Model for the Formation of the Milky Way

A new chemodynamical model for the formation and evolution of a Milky Way type galaxy is introduced. In this scenario, the galaxy forms inside a slowly growing dark matter halo in a ΛCDM cosmology. In contrast to the simple merger and collapse scenarios, the galactic mass grows continuously over a Hubble time. The whole formation scenario is simulated with a three-dimensional chemodynamical code. Within this model it is possible to follow the evolution of the galactic substructure in detail. The structure of the galactic components — halo, bulge, and disk — and the kinematical and chemical signatures of the stellar populations in the model are in excellent agreement with data from the Milky Way. The present model provides a detailed formation scenario for the Milky Way Galaxy and it yields new information about its kinematical and chemical history. The model predicts that even galaxies like the Milky Way show phases with supernova-driven galactic winds. However, with a mass loss of the order of only a few per cent of the total baryonic mass, these galaxies are in all probability not the main contributors to the enrichment of the intergalactic mediu

Til det beste for Sverige? Svenske myndigheter og den Mosaiska församlingen i Stockholm sin politikk overfor jødiske displace persons 1945 til 1950

In the last weeks of the Second World War and the following months Sweden played a crucial role in saving more than 30.000 non-Jewish and Jewish prisoners from German concentration camps, carrying them with the White Buses to Sweden. One of the mayor reasons for this action was to regain the positive relations to the Allied powers which had been seriously damaged during the first years of the war. The Jewish group counted 11-12.000 persons, mostly young women. An analysis of the treatment of these Jewish displaced persons by the Swedish authorities and the Jewish community in Stockholm from 1945 to 1950 shows that the authorities conducted their policy according to national interests and that the Jewish community was characterized by caution to keep the benevolence of the authorities. It was not considered a Swedish interest that they would stay, but after a few months the authorities, influenced among others by the Jewish Community, realized that forced repatriation was neither feasible out of humanitarian nor international political considerations. There were no restrictions for giving them medical help, but the treatment of these persons did not pay much attention to their psychic condition. One example is the use of their working power soon after their arrival in Sweden. Together with other displaced persons and refugees they became an important working power in building the Swedish welfare state, folkhemmet. Therefore, their inability to repatriate never became a problem for Sweden

Booms and Busts: the Burstiness of Star Formation in Nearby Dwarf Galaxies

In this review I summarise recent advances in our understanding of the importance of starburst events to the evolutionary histories of nearby galaxies. Ongoing bursts are easily diagnosed in emission-line surveys, but assessing the timing and intensity of fossil bursts requires more effort, usually demanding color-magnitude diagrams or spectroscopy of individual stars. For ages older than ~1 Gyr, this type of observation is currently limited to the Local Group and its immediate surroundings. However, if the Local Volume is representative of the Universe as a whole, then studies of the age and metallicity distributions of star clusters and resolved stellar populations should give statistical clues as to the frequency and importance of bursts to the histories of galaxies in general. Based on starburst statistics in the literature and synthetic colour-magnitude diagram studies of Local Group galaxies, I attempt to distinguish between systemic starbursts that strongly impact galaxy evolution and stochastic bursts that can appear impressive but are ultimately of little significance on gigayear timescales. As a specific case, it appears as though IC 10, the only starburst galaxy in the Local Group, falls into the latter category and is not fundamentally different from other nearby dwarf irregular galaxies.Comment: Accepted by the Publications of the Astronomical Society of Australia (PASA). Summary of a review talk given at the Southern Cross Astrophysics Conference on "Galaxy Metabolism" held in Sydney, 22-26 June 2009. 9 pages, 2 figure

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

.… å motivere til mestring

Denne oppgaven tar opp utfordringer vi som sykepleiere står overfor i forhold til å motivere personer som enten står i fare for å utvikle diabetes-2, eller nylig har fått diagnosen, og har behov for å endre livsstil. Vi har valgt å gjøre en litteraturstudie i denne oppgaven, som har fått tittelen; … å motivere til mestring I oppgaven har vi blant annet valgt å se nærmere på hvordan den innledende relasjonsbyggingen og kommunikasjonen med pasienten har betydning for den videre prosessen mot atferdsendring, sett i lys av blant annet empowermentbegrepet, motivering, veiledning og opplæring. I den forbindelse tok vi med diktet ”Om at hjelpe” av Søren Kierkegaard da vi mener han her tar for seg mye av essensen i sykepleier pasient relasjonen. Problemstillingen vi har kommet frem til er: Hvordan kan vi som sykepleiere motivere pasienter med diabetes-2, til å gjennomføre helsefremmende livsstilsendringer? For å kunne motivere en pasient med diabetes-2 har vi kommet frem til at vi bør opprette en god profesjonell relasjon med pasienten, som bygger på tillit og likeverd. Vi må besitte nødvendig kunnskap om sykdommen, og om de mest hensiktsmesige metodene for å fremme atferdsendring. Empowerment er et sentralt begrep i denne prosessen. Det er pasienten selv som har ansvar for egen helse, men vi må fremme pasientens egen vilje til å ta dette ansvaret, og støtte han til å gjennomføre de nødvendige endringene

The effect of clouds on the dynamical and chemical evolution of gas-rich dwarf galaxies

We study the effects of clouds on the dynamical and chemical evolution of gas-rich dwarf galaxies, in particular focusing on two model galaxies similar to IZw18 and NGC1569. We consider both scenarios, clouds put at the beginning of the simulation and continuously created infalling ones. Due to dynamical processes and thermal evaporation, the clouds survive only a few tens of Myr, but during this time they act as an additional cooling agent and the internal energy of cloudy models is typically reduced by 20 - 40% in comparison with models without clouds. The clouds delay the development of large-scale outflows, therefore helping to retain a larger amount of gas inside the galaxy. However, especially in models with continuous creation of infalling clouds, their bullet effect can pierce the expanding supershell and create holes through which the superbubble can vent freshly produced metals. Moreover, assuming a pristine chemical composition for the clouds, their interaction with the superbubble dilutes the gas, reducing the metallicity (by up to ~ 0.4 dex) with respect to the one attained by diffuse models.Comment: 3 pages, 3 figures, to be published in Astronomische Nachrichten (proceedings of Symposium 6 of the JENAM 2008, Vienna

Building Galactic Disks in Triaxial Dark Matter Halos

We review our recent work on the formation and evolution of disks with in triaxial dark matter (DM) halos by means of numerical simulations, including star formation and feedback from stellar evolution. The growing disks are strongly in fluenced by shapes of DM halos and modify them in turn. Disk parameters are in a broad agreement with those in the local universe. Gas-rich stellar bars grow in tandem with the disk and facilitate the angular momentum redistribution in the system and radial gas inflow. Nested bars appear to form as a by-product. Interactions between various non-axisymmetric components -- bars, disks and halos lead to decay of bars or washing out of ellipticity in the inner halo.Comment: 4 pages, 3 figures, invited talk at IAU Symp. 235 on Galaxy Evolution Across the Hubble Time, F. Combes and J. Palous (eds.), Cambridge U. Pres

Peripherisierung und räumliche Mobilität im ländlichen Raum

Selektive Wanderungsbewegungen, Überalterung und Schrumpfung bestimmen seit zwei Dekaden den Kurs des sozialen Wandels in zahlreichen ländlichen Regionen Deutschlands. Eine flächendeckende und effiziente Ausgestaltung ländlicher Gemeinden mit Versorgungsstrukturen und -gütern kann immer weniger geleistet werden. Für die Erfüllung sowohl alltäglich anfallender Versorgungsbedürfnisse als auch für die Ausübung beruflicher Tätigkeiten oder Freizeitaktivitäten ist räumliche Mobilität daher in zunehmendem Maß erforderlich. Die Chance der Bürger in das gesellschaftliche Leben integriert zu sein, ist demnach insbesondere im ländlichen Raum wesentlich geprägt durch die Möglichkeit räumlich mobil zu sein. Weiterhin werden politische Zielsetzungen vor dem Hintergrund des Klimawandels formuliert. Etwa Verkehrsbelastungen zu minimieren und Emissionen und Ressourcenverbrauch zu senken sind seit 2002 in der Nachhaltigkeitsstrategie der Bundesregierung verankert. In diesen komplexen Entwicklungen wird die Notwendigkeit eines Umdenkens gesehen, aus welchen zahlreiche Bemühungen erwachsen, den Verkehr ökologisch nachhaltig zu gestalten bzw. mit Mitteln technologischer Entwicklung zu substituieren.