Evidence for a companion to BM Gem, a silicate carbon star

Balmer and Paschen continuum emission as well as Balmer series lines of P Cygni-type profile from H_gamma through H_23 are revealed in the violet spectra of BM Gem, a carbon star associated with an oxygen-rich circumstellar shell (`silicate carbon star') observed with the high dispersion spectrograph (HDS) on the Subaru telescope. The blue-shifted absorption in the Balmer lines indicates the presence of an outflow, the line of sight velocity of which is at least 400 km s^-1, which is the highest outflow velocity observed to date in a carbon star. We argue that the observed unusual features in BM Gem are strong evidence for the presence of a companion, which should form an accretion disk that gives rise to both an ionized gas region and a high velocity, variable outflow. The estimated luminosity of ~0.2 (0.03-0.6) L_sun for the ionized gas can be maintained by a mass accretion rate to a dwarf companion of ~10^-8 M_sun yr^-1, while ~10^-10 M_sun yr^-1 is sufficient for accretion to a white dwarf companion. These accretion rates are feasible for some detached binary configurations on the basis of the Bond-Hoyle type accretion process. We concluded that the carbon star BM Gem is in a detached binary system with a companion of low mass and low luminosity. However, we are unable to determine whether this companion object is a dwarf or a white dwarf. The upper limits for binary separation are 210 AU and 930 AU for a dwarf and a white dwarf, respectively. We also note that the observed features of BM Gem mimic those of Mira (omi Cet), which may suggest actual similarities in their binary configurations and circumstellar structures.Comment: 11 pages, 2 figures, 1 table, accepted for publication in Ap

How Many Varieties of Capitalism? Comparing the Comparative Institutional Analyses of Capitalist Diversity

This essay reviews the development of approaches within the comparative capitalisms (CC) literature and points to three theoretical innovations which, taken together, define and distinguish these approaches as a group. First, national economies are characterized by distinct institutional configurations that generate a particular systemic 'logic' of economic action. Second, the CC literature suggests a theory of comparative institutional advantage in which different institutional arrangements have distinct strengths and weaknesses for different kinds of economic activity. Third, the literature has been interpreted to imply a theory of institutional path dependence. Behind these unifying characteristics of the literature, however, lie a variety of analytical frameworks and typologies of capitalism. This paper reviews and compares these different frameworks by highlighting the fundamental distinctions among them and drawing out their respective contributions and limitations in explaining economic performance and institutional dynamics. The paper concludes that the way forward for this literature lies in developing a more dynamic view of individual institutions, the linkages between domains, and the role of politics and power.In diesem Discussion Paper werden Ansätze der Comparative-Capitalism-Diskussion vorgestellt. Sie haben drei theoretische Innovationen gemein. Erstens: Nationale Ökonomien werden durch institutionelle Konfigurationen geprägt, die auf jeweils eigene "systemische Logiken" wirtschaftlichen Handelns hinwirken. Zweitens: Die Comparative-Capitalism-Literatur beinhaltet eine Theorie der komparativen institutionellen Vorteile, der zufolge institutionellen Konfigurationen spezifische Wettbewerbsvorteile zugeordnet werden können. Zudem, drittens, beinhaltet die Comparative-Capitalism-Literatur auch eine implizite Theorie der Pfadabhängigkeit. Trotz dieser Gemeinsamkeiten unterscheiden sich die Ansätze hinsichtlich analytischer Zugriffe und Vorschläge zur Typologisierung nationaler Kapitalismen. Beim Vergleich dieser Ansätze werden besonders deren Stärken und Schwächen bei der Analyse wirtschaftlicher Performanz und institutioneller Entwicklungsdynamiken hervorgehoben. Der Aufsatz kommt zu dem Schluss, dass die Comparative-Capitalism-Literatur in dreierlei Hinsicht der Weiterentwicklung bedarf: hinsichtlich einer dynamischeren Modellierung von Institutionen, einem besseren Verständnis der Interaktion institutioneller Domänen und der Berücksichtigung von Macht und Politik in der Analyse von Produktionsregimen