Theoretical Isochrones with Extinction in the K Band. II. J - K versus K

We calculate theoretical isochrones in a consistent way for five filter pairs near the J and K band atmospheric windows (J-K, J-K', J-Ks, F110W-F205W, and F110W-F222M) using the Padova stellar evolutionary models of Girardi et al. We present magnitude transformations between various K-band filters as a function of color. Isochrones with extinction of up to 6 mag in the K band are also presented. As found for the filter pairs composed of H & K band filters, we find that the reddened isochrones of different filter pairs behave as if they follow different extinction laws, and that the extinction curves of Hubble Space Telescope NICMOS filter pairs in the color-magnitude diagram are considerably nonlinear. Because of these problems, extinction values estimated with NICMOS filters can be in error by up to 1.3 mag. Our calculation suggests that the extinction law implied by the observations of Rieke et al for wavelengths between the J and K bands is better described by a power-law function with an exponent of 1.66 instead of 1.59, which is commonly used with an assumption that the transmission functions of J and K filters are Dirac delta functions.Comment: Published in PASP, 118, 62 (Jan. 2006

Evolution and Diffusion of the Michigan State University Tradition of Organizational Communication Network Research

This article documents the 30-year history of communication network research at Michigan State University (M.S.U.), providing a case study of the evolution and diffusion of an academic innovation. Three past and continuing issues for network scholars are identified: a lack of professional reward for developing user-friendly computer programs, unresolved methodological problems, and a need for better theoretical and conceptual frameworks. The narrative also illustrates the difficulty communication as a discipline has in impacting broader intellectual traditions. The story begins with the first doctoral dissertation (Schwartz, 1968) and the first network analysis software program in 1970 (Richards’ Negopy), continuing to the last dissertation (Susskind, 1996), and ending in 1998 when J. David Johnson left the M.S.U. faculty. Other major players in the M.S.U. network tradition included David K. Berio, Eugene Jacobson, Everett M. Rogers, Vincent Farace, Peter Monge, and Erwin Bettinghaus. Ironically, Schwartz and Susskind met in 1998 while Schwartz was preparing to retire from Cornell University and Susskind was starting as an Assistant Professor in a different department, thus providing closure to the M.S.U. network