Discovery of Candidate H2_2O Disk Masers in AGN and Estimations of Centripetal Accelerations

Based on spectroscopic signatures, about one-third of known H$_2$O maser sources in active galactic nuclei (AGN) are believed to arise in highly inclined accretion disks around central engines. These "disk maser candidates" are of interest primarily because angular structure and rotation curves can be resolved with interferometers, enabling dynamical study. We identify five new disk maser candidates in studies with the Green Bank Telescope, bringing the total number published to 30. We discovered two (NGC1320, NGC17) in a survey of 40 inclined active galaxies (v_{sys}< 20000 kms^{-1}). The remaining three disk maser candidates were identified in monitoring of known sources: NGC449, NGC2979, NGC3735. We also confirm a previously marginal case in UGC4203. For the disk maser candidates reported here, inferred rotation speeds are 130-500 kms^{-1}. Monitoring of three more rapidly rotating candidate disks (CG211, NGC6264, VV340A) has enabled measurement of likely orbital centripetal acceleration, and estimation of central masses (2-7x10^7 M_\odot) and mean disk radii (0.2-0.4pc). Accelerations may ultimately permit estimation of distances when combined with interferometer data. This is notable because the three AGN are relatively distant (10000<v_{sys}<15000 kms^{-1}). As signposts of highly inclined geometries at galactocentric radii of \sim0.1-1pc, disk masers also provide robust orientation references that allow analysis of (mis)alignment between AGN and surrounding galactic stellar disks, even without interferometric mapping. We find no preference among published disk maser candidates to lie in high-inclination galaxies, providing independent support for conclusions that central engines and galactic plane orientations are not correlated. (ABRIDGED)Comment: 7 figures, accepted for publication in ApJ, Dec. 10, 200

UBVRI Light Curves of 44 Type Ia Supernovae

We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from 1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The data set comprises 2190 observations and is the largest homogeneously observed and reduced sample of SN Ia to date, nearly doubling the number of well-observed, nearby SN Ia with published multicolor CCD light curves. The large sample of U-band photometry is a unique addition, with important connections to SN Ia observed at high redshift. The decline rate of SN Ia U-band light curves correlates well with the decline rate in other bands, as does the U-B color at maximum light. However, the U-band peak magnitudes show an increased dispersion relative to other bands even after accounting for extinction and decline rate, amounting to an additional ~40% intrinsic scatter compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication in the Astronomical Journal. Version with high-res figures and electronic data at http://astron.berkeley.edu/~saurabh/cfa2snIa

Book review: diaspora online: identity politics and Romanian migrants by Ruxandra Trandafoiu

In this book Ruxandra Trandafoiu sets out to chronicle the online cultural and political expressions of the Romanian diaspora, using websites based in Europe and North America. Through online exchanges, Romanians perform new types of citizenship, articulated from the margins of the political field. The author presents a plausible and intriguing picture of the Romanian diaspora online, writes James Koranyi

Voyages of Socialist Discovery: German-German Exchanges between the GDR and Romania

This article explores the little-known history of German-German exchanges between East Germany and Romania during the Cold War. It reveals a complex picture of tourism, travel and information exchange in which Germans from both countries were able to construct socialist escapes. While the Cold War history of Germans in East-Central Europe has tended to either ignore their presence or focus mainly on expulsion and emigration, this article highlights the vibrant existence of a ‘German sphere’ in Cold War East-Central Europe

Opposing Memories: Contest and Conspiracy over 1970s Romania

The history of Romanian dissidence during the Cold War often seems rather barren. Yet, as this article demonstrates, the legacy of Romanian opposition to Cold War communism is vexed with conflicts over ownership in a fragmented circle of late Cold War era oppositional voices and actors. A daring attempt to cross the Danube by a young Romanian German student in 1970 and an earthquake in the year 1977 provide the historical backdrop to these post-communist internecine battles over opposition and conformity. The prominence of the German-speaking community in these conflicts is not accidental but is itself a commentary on the structural problems related to dissidence in Romania. This article’s focus on specific individuals – Anton Sterbling, Paul Goma, Carl Gibson, Herta Müller – reveals differing interpretations of dissidence and opposition, a diverse social fabric of Romanian dissidence, and a long tail of psychological battles over the memory and the ownership of opposition to Romanian communism after 1989