Comparing Caddo and Coles Creek Pottery Using Petrographic Analysis

Pottery classified as “Coles Creek Incised” is common both to the earliest Caddo sites along the Red River and to contemporary sites in the Lower Mississippi Valley. Although it often is suggested that Coles Creek pottery from the two regions can be distinguished by differences in paste, no detailed comparative studies have been carried out. An initial attempt to identify variation through the use of petrographic analysis was carried out by comparing 50 samples drawn from sites in northwest and central Louisiana. Although no sharp dichotomy was noted between the regions, the study identified distinctions that support the notion that most Coles Creek pottery was made locally and different technological traditions may be represented

Galactic Winds

Galactic winds are the primary mechanism by which energy and metals are recycled in galaxies and are deposited into the intergalactic medium. New observations are revealing the ubiquity of this process, particularly at high redshift. We describe the physics behind these winds, discuss the observational evidence for them in nearby star-forming and active galaxies and in the high-redshift universe, and consider the implications of energetic winds for the formation and evolution of galaxies and the intergalactic medium. To inspire future research, we conclude with a set of observational and theoretical challenges.Comment: Paper to be published in 2005 Annual Review of Astronomy & Astrophysics; revision based on comments from readers and production editor. Figure 1 was replaced to show the proper density scale. A PDF file combining both text and figures is available at http://www.astro.umd.edu/~veilleux/pubs/araa.pd

Large scale excitation of the ISM in NGC 1068

Researchers have shown that photoionization by the continuum of the hidden Seyfert I nucleus in NGC 1068 can have a significant effect on the ionization state and energetics of this disk's Interstellar Medium (ISM). Photoionization models with appropriate power law spectra can produce (NII) lambda lambda 6538, 6584/H alpha line ratios of 1.25 for ionization parameters Q approx. 10 (exp -12). However the data indicate large regions where the (NII)/H alpha ratio is 1 to 3. Since the abundances are known to be solar, there must be additional heating sources. Hardening of the incident radiation field by intervening absorption should be able to raise T sub e, thereby raising the (NII)/H alpha ratio. Heating with moderate efficiency by the intense starburst ring should also be a significant factor in raising the temperature of the ISM. The photoionization models with additional heating predict enhanced emission from other forbidden lines including (OII) lambda 3727 and (SII) lambda 6731

A Side of Mercury Not Seen By Mariner 10

More than 60,000 images of Mercury were taken at ~29 deg elevation during two sunrises, at 820 nm, and through a 1.35 m diameter off-axis aperture on the SOAR telescope. The sharpest resolve 0.2" (140 km) and cover 190-300 deg longitude -- a swath unseen by the Mariner 10 spacecraft -- at complementary phase angles to previous ground-based optical imagery. Our view is comparable to that of the Moon through weak binoculars. Evident are the large crater Mozart shadowed on the terminator, fresh rayed craters, and other albedo features keyed to topography and radar reflectivity, including the putative huge ``Basin S'' on the limb. Classical bright feature Liguria resolves across the northwest boundary of the Caloris basin into a bright splotch centered on a sharp, 20 km diameter radar crater, and is the brightest feature within a prominent darker ``cap'' (Hermean feature Solitudo Phoenicis) that covers the northern hemisphere between longitudes 140-250 deg. The cap may result from space weathering that darkens via a magnetically enhanced flux of the solar wind, or that reddens low latitudes via high solar insolation.Comment: 7 pages, 4 PDF figures, pdfLaTeX, typos corrected, Fig. 2 modified slightly to add crater diameters not given in published versio

2008 Field Excavation Final Report Acosta-Durst-Taylor House

The Acosta-Durst-Taylor site (now known as the Durst-Taylor House) is known as one of the earliest occupations in Nacogdoches, TX. The property fronts North Street and is just to the north of Hospital Street (Figure 1). Much of the history of this plot of land and accompanying house, out structures, and other buildings associated with this land is described thoroughly in the site’s National Register of Historic Places nomination form (United States Department of the Interior 2003). What follows is a brief synopsis of the changing landscape of site 41NA182

The Contact Period of Central Peten, Guatemala in Color

When Bernal Díaz del Castillo passed by Nojpeten with Hernán Cortés in 1525, he remarked upon the Itza capital’s brilliant whiteness, even from a great distance (Jones 1998:69). However had he stood in the central plaza, he would have discerned that the sun’s reflection eclipsed artifacts and architecture of a variety of colors. The archaeological record is frequently similarly whitewashed by our focus upon form, weight, and distribution. Nevertheless, color helped imbue the Contact period (AD 1525-1697) world of the Maya of the Petén lakes region of Guatemala with significance. This paper investigates the colors of ritual paraphernalia encountered in Contact period ritual contexts in the Kowoj region of Petén, Guatemala with special concern with architecture, ceramics, and beads. These artifacts indicate the significance of particular colors and possibly the avoidance of the color yellow

Re-entrant ferroelectricity in liquid crystals

The ferroelectric (Sm C$^*$) -- antiferroelectric (Sm C$^*_A$) -- reentrant ferroelectric (re Sm C$^*$) phase temperature sequence was observed for system with competing synclinic - anticlinic interactions. The basic properties of this system are as follows (1) the Sm C$^*$ phase is metastable in temperature range of the Sm C$^*_A$ stability (2) the double inversions of the helix handedness at Sm C$^*$ -- Sm C$^*_A$ and Sm C$^*_A$% -- re-Sm C$^*$ phase transitions were found (3) the threshold electric field that is necessary to induce synclinic ordering in the Sm C$^*_A$ phase decreases near both Sm C$^*_A$ -- Sm C$^*$ and Sm C$^*_A$ -- re-Sm C$^*$ phase boundaries, and it has maximum in the middle of the Sm C$^*_A$ stability region. All these properties are properly described by simple Landau model that accounts for nearest neighboring layer steric interactions and quadrupolar ordering only.Comment: 10 pages, 5 figures, submitted to PR