Browsing by Subject "color"

Now showing 1 - 6 of 6

The Effect of Spatial Gradients in Stellar Mass-to-Light Ratio on Black Hole Mass Measurements
(2013-05) McConnell, Nicholas J.; Chen, Shi-Fan Steven; Ma, Chung-Pei; Greene, Jenny E.; Lauer, Tod R.; Gebhardt, Karl; Gebhardt, Karl
We have tested the effect of spatial gradients in stellar mass-to-light ratio (gamma) on measurements of black hole masses (M-*) derived from stellar orbit superposition models. Such models construct a static gravitational potential for a galaxy and its central black hole, but typically assume spatially uniform gamma. We have modeled three giant elliptical galaxies with gradients alpha d log(gamma)/d log(r) from -0.2 to + 0.1. Color and line strength gradients suggest mildly negative a in these galaxies. Introducing a negative (positive) gradient in gamma increases (decreases) the enclosed stellar mass near the center of the galaxy and leads to systematically smaller (larger) M-* measurements. For models with alpha = -0.2, the best-fit values of M-* are 28%, 27%, and 17% lower than the constant-gamma case, in NGC 3842, NGC 6086, and NGC 7768, respectively. For alpha = + 0.1, M-* are 14%, 22%, and 17% higher than the constant-gamma case for the three respective galaxies. For NGC 3842 and NGC 6086, this bias is comparable to the statistical errors from individual modeling trials. At larger radii, negative (positive) gradients in gamma cause the total stellar mass to decrease (increase) and the dark matter fraction within one effective radius to increase (decrease).
Letter to H.B. Stenzel from Charles W. Copeland on 1962-10-25
(1962-10-25) Copeland, Charles W.
Mapping The Interstellar Medium With Near-Infrared Diffuse Interstellar Bands
(2015-01) Zasowski, Gail; Menard, B.; Bizyaev, Dmitry; Garcia-Hernandez, D. Anibal; Perez, A. E. G.; Hayden, M. R.; Holtzman, Jon; Johnson, John A.; Kinemuchi, K.; Majewski, Steven R.; Nidever, David L.; Shetrone, Matthew; Wilson, J. C.; Shetrone, Matthew
We map the distribution and properties of the Milky Way's interstellar medium as traced by diffuse interstellar bands (DIBs) detected in near-infrared stellar spectra from the SDSS-III/APOGEE survey. Focusing exclusively on the strongest DIB in the H band, at lambda similar to 1.527 mu m, we present a projected map of the DIB absorption field in the Galactic plane, using a set of about 60,000 sightlines that reach up to 15 kpc from the Sun and probe up to 30 mag of visual extinction. The strength of this DIB is linearly correlated with dust reddening over three orders of magnitude in both DIB equivalent width (Wpm) and extinction, with a power law index of 1.01 +/- 0.01, a mean relationship of W-DIB/A(v) = 0.1 angstrom mag(-1) and a dispersion of similar to 0.05 angstrom mag(-1) at extinctions characteristic of the Galactic midplane. These properties establish this DIB as a powerful, independent probe of dust extinction over a wide range of Av values. The subset of about 14,000 robustly detected DIB features have a W-DIB distribution that follows an exponential trend. We empirically determine the intrinsic rest wavelength of this transition to be lambda(0) = 15 272.42 angstrom and use it to calculate absolute radial velocities of the carrier, which display the kinematical signature of the rotating Galactic disk. We probe the DIB carrier distribution in three dimensions and show that it can be characterized by an exponential disk model with a scale height of about 100 pc and a scale length of about 5 kpc. Finally, we show that the DIB distribution also traces large-scale Galactic structures, including the Galactic long bar and the warp of the outer disk.
The Mixed Race Experience: A One-Man Collection of Short Stories
(2020-05) Kirkley, Louis Young
This thesis is my collection of short fictional stories that attempts to realistically portray a person’s experience of being mixed race in 21st-century United States. Mainly, how do they deal with answering the inevitable question, “What are you?” Each story focuses on a character from a particular group (i.e. having an African American parent and a white parent, being an international student from Brazil, or being half-Korean) and how they grapple with their identity amidst conflict. The conflicts symbolize the clashing of different racial ideologies and at times, the forced imposition of such ideologies on the characters. The inspirations for the characters are from people’s experiences and theories found in literature and my own life as a person of mixed race. Although each story delves into subjects specific to different identity groups, they are written as parts of one collection to create a narrative of mixed-race life in the modern U.S. The goal of this thesis is not to tell every possible story, but to tell an experience that any person of mixed race—whether they match the characters or not—can empathize with and connect to, while still honoring the uniqueness of the identity groups present in the stories. If they are relatable, then they qualitatively support the mixed-race theories and implications that the stories draw inspiration from.
Murals And Floor Paintings At 'Ain Ghazal
(Ex Oriente, 2013) Schmandt-Besserat, Denise
Painting on interior walls and floors of houses was a common practice at ‘Ain Ghazal. The chapter describes the panels of flat white or red color and the few red-on-yellow, or red-on-white linear compositions. The colorants are discussed, in particular lime for white, ochre for red, and limonite for yellow, as well as the techniques involved. The ‘Ain Ghazal assemblage is then compared to those of contemporaneous sites before reviewing the traditional ancient Near East color symbolism as revealed by the Bronze Age cuneiform texts. Finally the paintings are shown to reflect the cognitive skills of a Neolithic community
A Study of Gasolines Sold in Texas and Review of Gasoline Specifications
(University of Texas at Austin, 1935-11-15) University of Texas at Austin