Galaxy And Mass Assembly (GAMA): understanding the wavelength dependence of galaxy structure with bulge-disc decompositions

With a large sample of bright, low-redshift galaxies with optical–near-IR imaging from the GAMA survey we use bulge-disc decompositions to understand the wavelength-dependent behaviour of single-Sersic structural measurements. We denote the variation in single-Sersic index with wavelength as N, likewise for effective radius we use R. We find that most galaxies with a substantial disc, even those with no discernable bulge, display a high value of N. The increase in Sersic index to longer wavelengths is therefore intrinsic to discs, apparently resulting from radial variations in stellar population and/or dust reddening. Similarly, low values of R (< 1) are found to be ubiquitous, implying an element of universality in galaxy colour gradients. We also study how bulge and disc colour distributions vary with galaxy type. We find that, rather than all bulges being red and all discs being blue in absolute terms, both components become redder for galaxies with redder total colours. We even observe that bulges in bluer galaxies are typically bluer than discs in red galaxies, and that bulges and discs are closer in colour for fainter galaxies. Trends in total colour are therefore not solely due to the colour or flux dominance of the bulge or disc

JWST's PEARLS: TN J1338-1942 -- I. Extreme jet triggered star-formation in a z=4.11 luminous radio galaxy

We present the first JWST observations of the z = 4.11 luminous radio galaxy TN J1338–1942, obtained as part of the ‘Prime Extragalactic Areas for Reionization and Lensing Science’ (‘PEARLS’) project. Our NIRCam observations, designed to probe the key rest-frame optical continuum and emission line features at this redshift, enable resolved spectral energy distribution modelling that incorporates both a range of stellar population assumptions and radiative shock models. With an estimated stellar mass of log10(M/M) ∼ 10.9, TN J1338–1942 is confirmed to be one of the most massive galaxies known at this epoch. Our observations also reveal extremely high equivalent-width nebular emission coincident with the luminous AGN jets that is best fit by radiative shocks surrounded by extensive recent star formation. We estimate the total star-formation rate (SFR) could be as high as ∼ 1600 M yr−1 , with the SFR that we attribute to the jet induced burst conservatively 500 M yr−1. The mass-weighted age of the star-formation, tmass < 4 Myr, is consistent with the likely age of the jets responsible for the triggered activity and significantly younger than that measured in the core of the host galaxy. The extreme scale of the potential jet-triggered star-formation activity indicates the potential importance of positive AGN feedback in the earliest stages of massive galaxy formation, with our observations also illustrating the extraordinary prospects for detailed studies of high-redshift galaxies with JWST.KJD acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement number 892117 (HIZRAD) and support from the STFC through an Ernest Rutherford Fellowship (grant number ST/W003120/1). RAW, SHC, and RAJ acknowledge support from NASA JWST Interdisciplinary Scientist grants NAG5-12460, NNX14AN10G, and 80NSSC18K0200 from GSFC. Work by CJC acknowledges support from the European Research Council (ERC) Advanced Investigator Grant EPOCHS (788113). BLF thanks the Berkeley Center for Theoretical Physics for their hospitality during the writing of this paper. MAM acknowledges the support of a National Research Council of Canada Plaskett Fellowship, and the Australian Research Council center of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE17010001. CNAW acknowledges funding from the JWST/NIRCam contract NASS-0215 to the University of Arizona. TAH is supported by an appointment to the NASA Postdoctoral Program (NPP) at NASA Goddard Space Flight Center, administered by Oak Ridge Associated Universities under contract with NASA.Peer reviewe

Education for Tragedy: Essays in Disenchanted Hope for Modern Man

A distinguished educator and social critic here considers the demands put upon democratic and progressive policies in education, which remains, he believes, man’s strongest hope for creating new bases for human values in an age of change and cultural crisis. The importance of human worth and individual advancement, within communities and varied age demographics, is analyzed. “A sensitive and penetrating analysis of the cultural crisis of our time . . . offers fruitful approaches for restructuring human values and social relations. —The Educational Forumhttps://uknowledge.uky.edu/upk_social_and_philosophical_foundations_of_education/1000/thumbnail.jp

Continuity and Discontinuity In Educational Development

"Development" has become a god-term in the thinking and rhetoric of theorists and practitioners of the contemporary arts of politics, economics and education. It points to an area of thought and action which links theorizing and research on the one hand with needed alterations hopefully, improvements - in economic, political, social and educational practices on the other. This mid-ground between basic and disinterested investigations of phenomena and customary and traditional arts of practice is, of course, the domain of technology and engineering. The products of developmental research are technologies, principles and strategies of making, doing and organizing which, on the one hand, are knowledgebased and also are shaped relevantly to the improvement of practice, to the better meeting of unmet or inadequately met human and social needs

The improvement of practical intelligence : the central tast of education

viii, 303 hal.; 21 cm