Unveiling the Role of the Magnetic Field at the Smallest Scales of Star Formation

We report Atacama Large Millimeter/submillimeter Array (ALMA) observations of polarized dust emission from the protostellar source Ser-emb 8 at a linear resolution of 140 au. Assuming models of dust-grain alignment hold, the observed polarization pattern gives a projected view of the magnetic field structure in this source. Contrary to expectations based on models of strongly magnetized star formation, the magnetic field in Ser-emb 8 does not exhibit an hourglass morphology. Combining the new ALMA data with previous observational studies, we can connect magnetic field structure from protostellar core (̃80,000 au) to disk (̃100 au) scales. We compare our observations with four magnetohydrodynamic gravo-turbulence simulations made with the AREPO code that have initial conditions ranging from super-Alfvénic (weakly magnetized) to sub-Alfvénic (strongly magnetized). These simulations achieve the spatial dynamic range necessary to resolve the collapse of protostars from the parsec scale of star-forming clouds down to the ̃100 au scale probed by ALMA. Only in the very strongly magnetized simulation do we see both the preservation of the field direction from cloud to disk scales and an hourglass-shaped field at <1000 au scales. We conduct an analysis of the relative orientation of the magnetic field and the density structure in both the Ser-emb 8 ALMA observations and the synthetic observations of the four AREPO simulations. We conclude that the Ser-emb 8 data are most similar to the weakly magnetized simulations, which exhibit random alignment, in contrast to the strongly magnetized simulation, where the magnetic field plays a role in shaping the density structure in the source. In the weak-field case, it is turbulence—not the magnetic field—that shapes the material that forms the protostar, highlighting the dominant role that turbulence can play across many orders of magnitude in spatial scale.Astronom

Portable X-ray Fluorescence and Infrared Fluorescence Imaging Studies of Cadmium Yellow Alteration in Paintings by Edward Munch and Henri matisse in Oslo, Copenhagen, and San Francisco

The identification of altered cadmium yellow paints in early modernist works is critical to their stabilization and to the long-term preservation of the paintings in which they occur. The identification of incipient photoalteration of these pigments, before there is visual evidence of their chemical degradation, is of particular concern. The alteration of these pigments causes chalking, flaking, fading, and darkening of the yellow paints, leading to irreversible changes in the physical and chemical structure of the paint layer and dramatically altering the appearance of the work. Standoff methods for the identification of this phenomenon are desired to rapidly and efficiently survey the condition of the pigment across an entire work and also to minimize invasive and destructiveanalyses wherever possible. Such methods are a particular need for collections with large holdings of Impressionist and early modernist works from the 1880s to the 1920s, for which these cadmium yellow alterations are particularly problematic and a rapid surveying method for the collection is needed. To address this challenge, four standoff methods were attempted (both aloneand in concert): ultraviolet-induced visible fluorescence, ultraviolet-induced infrared fluorescence, multispectral imaging, and X-ray fluorescence. Questions addressed included the following: Is the imaging method being tested comprehensive? Is it efficient at surveying an entire painting? Does it reveal the state of preservation of the pigment? Does it reliably discriminate among intact versus altered cadmium yellow pigments? To answer these questions, the methods were tested on Henri Matisse’s Le Bonheur de vivre (1905–1906, the Barnes Foundation, Philadelphia) and oil sketches for this work in the San Francisco Museum of Modern Art and the Statens Museum for Kunst, Copenhagen. They were also tested on Edvard Munch’s The Scream (ca. 1910?, Munch Museum, Oslo). It was found that ultraviolet-induced visible fluorescence has the best ability to discriminate between altered and unaltered cadmium yellow paints (even before alteration is visible to the unaided eye), whereas multispectral imaging allows for the most efficient and comprehensive localization of the cadmium pigments in a work

MOESM1 of Reflectance imaging spectroscopy and synchrotron radiation X-ray fluorescence mapping used in a technical study of The Blue Room by Pablo Picasso

Additional file 1: Table S1. Summary of findings of cross-sectional analysis

Supporting Sanctuary Efforts: Trends in Apprehension Data

This research project is a collaboration with two migrant justice organizations from Oregon, Pueblo Unido PDX (PU) and the Rural Organizing Project (ROP), who requested the assistance of UW researchers in analyzing data related to federal immigration enforcement in their state. In particular, these organizations were interested in knowing the answers to three major questions: Who is being targeted? What tactics are being used? And how does this vary over time and space