Solar data from the Halogen Occultation Experiment (HALOE) were analyzed to determine the center-to-limb relative intensity and the vertical temperature profile for the quiet and active Sun over wavelengths from 2.4 to 10 {dollar}\mu{dollar}m. An algorithm that incorporated a nonlinear least squares procedure was developed that modeled the HALOE instrument during data acquisition. Data obtained from limb-to-limb scans along the solar equator on days of very low activity in May 1994 were analyzed to obtain coefficients of a function describing the relative intensity from center to limb. The relative intensities produced were precise to 0.1% (2{dollar}\sigma{dollar}) from the center to 0.25 arc min from the limb. The brightness temperature from the flux and the temperature as a function of monochromatic optical depth were also calculated from the coefficients. These quantities were normalized using published central intensities and compared to a semiemperical model of the photosphere. In general, the calculated temperature quantities were in good agreement with the model predictions; however, differences occurring between 2.4 and 3 {dollar}\mu{dollar}m suggest that the central intensities used here are low.;HALOE solar data were also investigated to obtain the intensity of a sunspot relative to the photosphere. A nonlinear least squares method was used to retrieve relative intensity information for a large sunspot on August 19, 1942. at each wavelength a one-component sunspot model proved sufficient to fit the measurements to the digitization level of the instrument. Sunspot/photosphere intensity ratios were calculated at each wavelength with an uncertainty of 2%. Compared with previous measurements at shorter wavelengths from 0.387 to 2.35 {dollar}\mu{dollar}m, the data exhibit the same general trend of larger ratios with increasing wavelengths; however, a larger than anticipated gap exists between the previous value at 2.35 {dollar}\mu{dollar}m and the HALOE ratio value at 2.45 {dollar}\mu{dollar}m. The photospheric and sunspot temperatures were calculated at each wavelength and show slight decreases with increasing wavelength. A steep drop exhibited by the previous measurements between 1.67 and 2.35 {dollar}\mu{dollar}m is not supported by HALOE values. Consideration of terrestrial atmospheric effects in the previous data could explain this discrepancy.

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Despite the Radio Arc non-thermal filaments (NTFs) being discovered 30 years ago, their origin remain poorly understood. The Radio Arc NTFs have an unusually flat spectrum in the centimeter to millimeter spectrum with a predicted, though poorly constrained, turn-over between 30-200 GHz. With the recently upgraded wide-band capabilities of the VLA, we conducted a multi-frequency polarimetric study of the Radio Arc region. With observations at a set of low radio frequencies (continuous coverage over 2-6 GHz & 10-12 GHz), we imaged both the total and polarized intensity distributions at high angular resolution (<1"). Presented here are the preliminary results from four observations spanning May 2013 to February 2014 using the DnC, CnB, B & BnA array configurations. This study has produced the deepest continuum intensity images of the Radio Arc region to date, with a sensitivity an order of magnitude greater than previous surveys, and resulted in the detection of new structure and compact emission sources. These observations will serve as a pilot polarization study for larger, more complete polarimetric surveys of the Galactic center region.

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We report the results of Faraday rotation measurements of 23 background radio sources whose lines of sight pass through or close to the Rosette Nebula. We made linear polarization measurements with the Karl G. Jansky Very Large Array (VLA) at frequencies of 4.4 GHz, 4.9 GHz, and 7.6 GHz. We find the background Galactic contribution to the rotation measure in this part of the sky to be +147 rad m-2. Sources whose lines of sight pass through the nebula have an excess rotation measure of 50-750 rad m-2, which we attribute to the plasma shell of the Rosette Nebula. We consider two simple plasma shell models and how they reproduce the magnitude and sign of the rotation measure, and its dependence on distance from the center of the nebula. These two models represent different modes of interaction of the Rosette Nebula star cluster with the surrounding interstellar medium. Both can reproduce the magnitude and spatial extent of the rotation measure enhancement, given plausible free parameters. We contend that the model based on a stellar bubble more closely reproduces the observed dependence of rotation measure on distance from the center of the nebula.

The ultraviolet auroral imaging photometer aboard the Dynamics Explorer 1 spacecraft was utilized to obtain measurements of the diffuse ultraviolet background radiation along two strips of the sky between Galactic latitudes —61° < b < 61°. The magnitude of the ultraviolet background was found to be 519 ± 28 photons (cm 2 sec  sr)-1 at a wavelength of 1500 Â, thus placing a much better restriction on the value of the diffuse radiation field than previous estimates.

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Quenching galaxies are galaxies that are rapidly evolving from strongly star forming systems to galaxies with mostly old stars and low star formation rates. When identifying quenching galaxies, there are several methods in common use. Furthermore, there are several ways astronomers estimate the Star Formation Rate (SFR), in Solar Masses per year, and Stellar Mass (M*), in Solar Masses, of galaxies. For a large sample of galaxies, we used 6 derivations of M* and 4 for SFR, plotting them against each other for comparison. We also calculated and compared the specific SFR (sSFR), equal to SFR/M*, and compared the different methods of defining quenched galaxies. Finally, we divided up these plots by classification, Red Sequence/Green Valley/Blue Cloud, and different values of log (SFR). This project was completed with the support of a grant from the NASA Tennessee Space Grant Consortium.