Large-scale variations of the dust optical properties in the Galaxy

We present an analysis of the dust optical properties at large scale, for the whole galactic anticenter hemisphere. We used the 2MASS Extended Source Catalog to obtain the total reddening on each galaxy line of sight and we compared this value to the IRAS 100 microns surface brightness converted to extinction by Schlegel et al (1998). We performed a careful examination and correction of the possible systematic effects resulting from foreground star contamination, redshift contribution and galaxy selection bias. We also evaluated the contribution of dust temperature variations and interstellar clumpiness to our method. The correlation of the near-infrared extinction to the far-infrared optical depth shows a discrepancy for visual extinction greater than 1 mag with a ratio A_V(FIR) / A_V(gal) = 1.31 +- 0.06. We attribute this result to the presence of fluffy/composite grains characterized by an enhanced far--infrared emissivity. Our analysis, applied to half of the sky, provides new insights on the dust grains nature suggesting fluffy grains are found not only in some very specific regions but in all directions for which the visual extinction reaches about 1 mag.Comment: 10 pages, 11 figures, accepted for publication in A&

On How to Extend the NIR Tully-Fisher Relation to be Truly All-Sky

Dust extinction and stellar confusion by the Milky Way reduce the efficiency of detecting galaxies at low Galactic latitudes, creating the so-called Zone of Avoidance. This stands as a stumbling block in charting the distribution of galaxies and cosmic flow fields, and therewith our understanding of the local dynamics in the Universe (CMB dipole, convergence radius of bulk flows). For instance, ZoA galaxies are generally excluded from the whole-sky Tully-Fisher Surveys ($|b| \leq 5^\circ$) even if catalogued. We show here that by fine-tuning the near-infrared TF relation, there is no reason not to extend peculiar velocity surveys deeper into the ZoA. Accurate axial ratios ($b/a$) are crucial to both the TF sample selection and the resulting TF distances. We simulate the effect of dust extinction on the geometrical properties of galaxies. As expected, galaxies appear rounder with increasing obscuration level, even affecting existing TF samples. We derive correction models and demonstrate that we can reliably reproduce the intrinsic axial ratio from the observed value up to extinction level of about $A_J\simeq3$ mag ($A_V\sim11$ mag), we also recover a fair fraction of galaxies that otherwise would fall out of an uncorrected inclination limited galaxy sample. We present a re-calibration of the 2MTF relation in the NIR $J$, $H$, and $K_s$-bands for isophotal rather than total magnitudes, using their same calibration sample. Both TF relations exhibit similar scatter at high Galactic latitudes. However, the isophotal TF relation results in a significant improvement in the scatter for galaxies in the ZoA, and low surface brightness galaxies in general, because isophotal apertures are more robust in the face of significant stellar confusion.Comment: 12 pages, 10 figures, 4 tables, accepted for publication in MNRA

Galaxy peculiar velocities in the Zone of Avoidance

Dust extinction and stellar confusion of the Milky Way hinder the detection of galaxies at low Galactic latitude, creating the so-called Zone of Avoidance (ZoA). This has hampered our understanding of the local dynamics, cosmic flow fields and the origin of the Cosmic Microwave Background dipole. The ZoA ($|b| \le 5^\circ$) is also excluded from the "whole-sky" Two Micron All-Sky Survey (2MASS) Redshift Survey (2MRS) and 2MASS Tully-Fisher Survey (2MTF). The latter aims to provide distances and peculiar velocities for all bright inclined 2MASS galaxies with $K_s^o$ \leq 11\hbox{.\!\!^{\rm m}}25. Correspondingly, knowledge about the density distribution in the ZoA remains limited to statistical interpolations. To improve on this bias we pursued two different surveys to fill in the southern and northern ZoA. These data will allow a direct measurement of galaxy peculiar velocities. In this paper we will present a newly derived optimized Tully-Fisher (TF) relation that allow accurate measures of galaxy distances and peculiar velocities for dust-obscured galaxies. We discuss further corrections for magnitudes and biases and present some preliminary results on flow fields in the southern ZoA.Comment: 6 pages, 3 figures, to appear in Proceedings of SAIP2013, the 58th Annual Conference of the South African Institute of Physics, edited by Roelf Botha and Thulani Jili (SAIP and University of Zululand, 2014). ISBN: 978-0-620-62819-

The Burley Tobacco Buyout Program and Its Impact on Farmers in Tennessee, Virginia, and North Carolina.

This thesis addresses the Burley Tobacco Buyout Program and its impact on three local economies. Data collection involved obtaining information from government reports, internet sources, public documents, agriculture offices, federal agriculture officials, and books. Personal interviews were conducted with 32 farmers in Sullivan County, Tennessee; Washington County, Virginia; and Watauga County, North Carolina. This study is significant because it addresses not only the decline of an agricultural product but also changes in a way of life in Southern Appalachia. The future of burley tobacco growing in this region appears to be bleak because of foreign market competition and decreasing domestic demand. From the personal interviews, many farmers had already abandoned tobacco production and older respondents were often planning to stop all farming practices. Specifics of the federal government-mandated Buyout Program to compensate quota holders and growers are presented, as well as the experiences and opinions of farmers regarding this program

Recalibrating the Wide-field Infrared Survey Explorer (WISE) W4 Filter

We present a revised effective wavelength and photometric calibration for the Wide-field Infrared Survey Explorer (WISE) W4 band, including tests of empirically motivated modifications to its pre-launch laboratory-measured relative system response curve. We derived these by comparing measured W4 photometry with photometry synthesised from spectra of galaxies and planetary nebulae. The difference between measured and synthesised photometry using the pre-launch laboratory-measured W4 relative system response can be as large as 0.3 mag for galaxies and 1 mag for planetary nebulae. We find the W4 effective wavelength should be revised upward by 3.3%, from 22.1 micron to 22.8 micron, and the W4 AB magnitude of Vega should be revised from m = 6.59 to m = 6.66. In an attempt to reproduce the observed W4 photometry, we tested three modifications to the pre-launch laboratory-measured W4 relative system response curve, all of which have an effective wavelength of 22.8 micron. Of the three relative system response curve models tested, a model that matches the laboratory-measured relative system response curve, but has the wavelengths increased by 3.3% (or 0.73 micron) achieves reasonable agreement between the measured and synthesised photometry.Comment: Accepted for publication in Publications of the Astronomical Society of Australia, 6 pages, 4 figures, 1 tabl

An Examination of the Specificity of Economic Loss and Deprivation and Community Violence on Depressive Symptoms and Aggressive Behavior in Urban, Low-Income Adolescents

Based on the current literature examining associations of stress and psychopathology in adolescents, several types of stress (e.g., violence exposure, economic-related stress) have been identified as particularly salient in lowincome, urban adolescent populations (Grant et al., 2003; Natz et al., 2012). This population also has been shown to be at heightened risk for problems including internalizing and externalizing symptoms. Identifying specific pathways through which urban, low-income adolescents develop specific emotional and behavior problems in response to particular stressors would be helpful in the development and selections of as the targets of interventions that disrupt mediators that link particular stressors to particular outcomes. In the present study, 201 urban adolescents completed a battery of questionnaires assessing stressful life events and emotional and behavioral problems in a short-term longitudinal study spanning six months that assessed their emotional and behavioral problems in response to stressors typically experienced in urban, low-income environments. Two stressor-outcome specificity models will be tested to better understand the mechanisms through which depressive symptoms and aggressive behaviors emerge among urban, low-income adolescents in response to economic loss an

Space shuttle: Static longitudinal, directional and lateral characteristics and control surface effectiveness of the MDAC-STS canard booster

Static longitudinal, directional, and lateral characteristics and control surface effectiveness of scale model of space shuttle canard booster at Mach 0.2

The 2MASS Tully-Fisher Survey : Mapping the Mass in the Universe

The 2MASS Tully-Fisher Survey (2MTF) aims to measure Tully-Fisher (TF) distances for all bright inclined spirals in the 2MASS Redshift Survey (2MRS) using high quality HI widths and 2MASS photometry. Compared with previous peculiar velocity surveys, the 2MTF survey provides more accurate width measurements and more uniform sky coverage, combining observations with the Green Bank, Arecibo and Parkes telescopes. With this new redshift-independent distance database, we will significantly improve our understanding of the mass distribution in the local universe.Comment: 4 pages, 3 figures, IAU Symposium 289 proceedin