Federal Influences and Intergovernmental Relations: Constraints, Conflicts, and Benefits

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Concentrated Poverty: A Change in Course

Examines how the distribution of concentrated poverty in metropolitan areas has shifted in the past two decades, using data from the Neighborhood Change Database

Have MTO Families Lost Access to Opportunity Neighborhoods Over Time?

Reviews research on families who moved to lower-poverty areas through the Moving to Opportunity program, using new data and broader indicators to assess whether their subsequent moves were also to better neighborhoods from which the families benefited

Population Growth and Decline in City Neighborhoods

Analyzes how neighborhoods in the nation's largest cities grew and declined in the 1990s and how those results compared with patterns of change in the 1980s, based on data from the U.S. Census and the Neighborhood Change Database

Concentrated Poverty: Dynamics of Change

Compares metropolitan census tracts that improved with respect to poverty in the 1990s with those that worsened, looking at the racial composition of both types and in different types of metropolitan areas nationally

Studying the Nature of Dark Energy with Galaxy Clusters

We report on the status of our effort to constrain the nature of dark energy through the evolution of the cluster mass function. Chandra temperature profiles for 31 clusters from a local cluster sample are shown. The X-ray appearance of the proto supermassive binary black hole at the center of the cluster Abell 400 is described. Preliminary weak lensing results obtained with Megacam@MMT for a redshift z=0.5 cluster from a distant cluster sample are given.Comment: 5 pages, to appear in: Aschenbach, B., Burwitz, V., Hasinger, G., Leibundgut, B. (eds.), Relativistic Astrophysics and Cosmology - Einstein's Legacy. ESO Astrophysics Symposia, Springer Verlag, Berlin, German

Comptonisation of Cosmic Microwave Background Photons in Dwarf Spheroidal Galaxies

We present theoretical modelling of the electron distribution produced by annihilating neutralino dark matter in dwarf spheroidal galaxies (dSphs). In particular, we follow up the idea of Colafrancesco (2004) and find that such electrons distort the cosmic microwave background (CMB) by the Sunyaev-Zeldovich effect. For an assumed neutralino mass of 10 GeV and beam size of 1'', the SZ temperature decrement is of the order of nano-Kelvin for dSph models with a soft core. By contrast, it is of the order of micro-Kelvin for the strongly cusped dSph models favoured by some cosmological simulations. Although this is out of reach of current instruments, it may well be detectable by future mm telescopes, such as ALMA. We also show that the upscattered CMB photons have energies within reach of upcoming X-ray observatories, but that the flux of such photons is too small to be detectable soon. Nonetheless, we conclude that searching for the dark matter induced Sunyaev-Zeldovich effect is a promising way of constraining the dark distribution in dSphs, especially if the particles are light.Comment: 10 pages, 5 figures, MNRAS, in pres

Studies of low-energy ionic collisions Final report, 1 Oct. 1965 - 30 Sep. 1967

Ionic-molecular collisions, and collision induced dissociation of ion