The Morphology of 9 Radio-selected Faint Galaxies from deep HST Imaging

Using the HST WFPC2 we perform deep I-band imaging of 9 radio-selected (limit 14 microJanskys at 8.5 GHz) faint galaxies from Roche, Lowenthal and Koo (2002). Two are also observed in V. Six of the galaxies have known redshifs of 0.4<z<1.0. Radial intensity profiles indicate that 7 are disk galaxies and 2 are bulge-dominated. Four of the six with redshifts have a high optical surface brightness compared to typical disk galaxies. Two of the 9 galaxies are in close interacting pairs, another two are very asymmetric and three have large, luminous rings resembling the collisional starburst rings in the Cartwheel galaxy. In most of these galaxies the high radio luminosities are probably the result of interaction-triggered starbursts. The mixture of observed morphologies suggests that enhanced radio luminosities often persist for >0.2 Gyr, to a late stage of the interaction. One of these 9 galaxies may be an exception in that it is a large red elliptical and its strong radio emission is more likely to be from an obscured AGN.Comment: 12 pages, latex, 8 figures, accepted for publication in MNRA

Are There Local Analogs of Lyman Break Galaxies?

To make direct comparisons in the rest-far-ultraviolet between LBGs at z~3 and more local star-forming galaxies, we use HST/STIS to image a set of 12 nearby (z<0.05) HII galaxies in the FUV and a set of 14 luminous compact blue galaxies (LCBGs) at moderate redshift (z~0.5) in the NUV, corresponding to the rest-FUV. We then subject both sets of galaxy images and those of LBGs at z~3 to the same morphological and structural analysis. We find many qualitative and quantitative similarities between the rest-FUV characteristics of distant LBGs and of the more nearby starburst samples, including general morphologies, sizes, asymmetries, and concentrations. Along with some kinematic similarities, this implies that nearby HII galaxies and LCBGs may be reasonable local analogs of distant Lyman break galaxies.Comment: 4 pages, 4 figures. To appear in "Starbursts: from 30 Doradus to Lyman Break Galaxies" 2005, eds. R. de Grijs and R. M. Gonzalez Delgado (Kluwer

Long-Term Effects of Activity Status in the Elderly on Cardiorespiratory Capacity, Blood Pressure, Blood Lipids, and Body Composition: A Five-Year Follow-Up Study

It is generally recognized that physical activity levels in the elderly do not remain constant over time, and typically there is a marked reduction in physical activities in the elderly. The long-term benefits of regular physical training programs in the elderly are still not fully understood. This is a study of 55 elderly healthy subjects (over 65 years old) and re-evaluated for the effects of different physical activity patterns (sedentary, moderately active, and highly active) on several physiological parameters (pre- and post-training) after a 5-year period (5.30 ± 1.14 years). Measurements included: body composition, blood lipid profiles, resting systolic and diastolic blood pressure, maximal oxygen uptake, and pulmonary function. Results indicated a larger decrease in maximal oxygen uptake (VO2max) in the group of elderly sedentary individuals (1.5 ± 0.5 l/min) compared to the moderately active (1.7 ± 0.6 l/min) and the highly active groups (1.9 ± 0.4 l/min). An active lifestyle was not sufficient to increase the physiological function of an individual.This study could not clearly demonstrate favorable differences for the physically active groups over the sedentary group with regard to several important physiological factors over the 5-year follow-up and it appears that the recommendation for, and the initiation of, adopting active lifestyles may not be sufficient on their own to significantly increase an individual's physiological functioning

X-ray Detections of Sub-millimetre Galaxies: Active Galactic Nuclei Versus Starburst Contribution

We present a large-scale study of the X-ray properties and near-IR-to-radio SEDs of submillimetre galaxies (SMGs) detected at 1.1mm with the AzTEC instrument across a ~1.2 square degree area of the sky. Combining deep 2-4 Ms Chandra data with Spitzer IRAC/MIPS and VLA data within the GOODS-N/S and COSMOS fields, we find evidence for AGN activity in ~14 percent of 271 AzTEC SMGs, ~28 percent considering only the two GOODS fields. Through X-ray spectral modeling and SED fitting using Monte Carlo Markov Chain techniques to Siebenmorgen et al. (2004) (AGN) and Efstathiou et al. (2000) (starburst) templates, we find that while star formation dominates the IR emission, with SFRs ~100-1000 M_sun/yr, the X-ray emission for most sources is almost exclusively from obscured AGNs, with column densities in excess of 10^23 cm^-2. Only for ~6 percent of our sources do we find an X-ray-derived SFR consistent with NIR-to-radio SED derived SFRs. Inclusion of the X-ray luminosities as a prior to the NIR-to-radio SED effectively sets the AGN luminosity and SFR, preventing significant contribution from the AGN template. Our SED modeling further shows that the AGN and starburst templates typically lack the required 1.1 mm emission necessary to match observations, arguing for an extended, cool dust component. The cross correlation function between the full samples of X-ray sources and SMGs in these fields does not indicate a strong correlation between the two populations at large scales, suggesting that SMGs and AGNs do not necessarily trace the same underlying large scale structure. Combined with the remaining X-ray-dim SMGs, this suggests that sub-mm bright sources may evolve along multiple tracks, with X-ray-detected SMGs representing transitionary objects between periods of high star formation and AGN activity while X-ray-faint SMGs represent a brief starburst phase of more normal galaxies.Comment: 23 pages, 10 figures, 6 tables. Accepted for publication in MNRA

The Pioneer Landscape: An American Dream

To speak of pioneers, of the pioneer character, of the pioneer spirit, instantly brings vivid impressi~ns to mind. But what and where is the pioneer landscape? No more elusive or evanescent place exists. The pioneer landscape appears here, there, almost everywhere, for only a moment early in the chronicle of any locale; then it vanishes, never to return. Only once in its history is a place a pioneer country. Other pioneering efforts may follow-the extraction of some hitherto unknown or unusable resource, the creation of some new social orderbut these efforts do not occur in pioneer landscapes or circumstances. Lindbergh pioneered in a complex machine produced by a team of experts and funded by big business. The whole world celebrated Lindy for doing it alone, but the flight was not the heroic lone success of a single daring individual, as John W. Ward has said, but the climax of the cooperative effort of an elaborately interlocked technology. The landscapes we mainly pioneer today are those of tourism, the fastest moving modern frontier after Dutch elm disease. Cleveland Amory\u27s The Last Resorts sets forth a Turnerian process of replacement-a sort of Gresham\u27s Law of intellectual pioneers followed by good and then bad millionaires. And some natives fear that England is fated to end up as a living museum for the delectation of American visitors- visitors as eager to see the lineaments of their remote European past as of their pioneer American heritage. But there is still a long way to go before tourist pioneers resettle the whole world. As the beginnings of settlement recede into the past, ever fewer people survive who have experienced actual pioneer landscapes. This helps to account for the present popularity of those landscapes. We increasingly hark back to a past we ourselves have never known, one more imagined than real. The romance of pioneering suits our wistful longing for ways of life so briefly and variously experienced that we invest them with whatever forms we choose. This longing brings us full circle from the original pioneers\u27 nostalgia for their previous homelands, celebrated in scores of doleful ballads collected by Theodore Blegen and others. PIONEER SCENES IN MODERN DISPLAY The pioneer landscape is but one of many realms of modern nostalgia. Preserving and recreating historic areas that exemplify bygone epochs and ways of life is a particularly American mode of expression. During the fIrst third of this century, colonial homes and eastern seaboard villages captured the popular imagination, museum period rooms and restored Williamsburg being the best-known examples. These displays featured aristocratic elegance, avoiding the commonplace or the humble. Later rebirths involved more representative workaday communities: Ford\u27s GreenfIeld and Old Sturbridge Village, refurbished Victorian towns with old-fashioned Main Streets and cracker-barrel stores, and, more recently, antebellum slave quarters and nineteenth-century New England factories and mill towns. The bucolic landscapes of shaker and Amish and Mennonite communities; boom-town mining camps instantly settled, violently occupied, and quickly abandoned; fortresses, battlefIelds, and sites of famous historical episodes likewise have widespread appeal. Frontier and wilderness nostalgia are catered to in the national parks, in Hollywood Hlms, and in the rodeos and dude ranches of cowboy country that were popular resorts for effete easterners for almost a century. Facsimiles of all these historic locales converge in Disney World\u27s fabulous pastiche

Mixing Levels of Revision

Orderly and straightforward revision, in which editorial tasks are delimited draft by draft, breaks down with lengthy and complex tasks. In rewriting a book, I have had to combine various stages of revision in each draft — adding new material, reshaping thoughts, striving for coherent expression, and polishing prose simultaneously instead of serially. This kaleidoscopic way of working yields unexpected advantages that compensate for its untidy clutter: it helps to maintain the pace of revision, resolves problems left over from previous drafts, and stimulates new ideas and reconsiderations which, at a late stage in the editorial process, come as necessary nuisances