Far Ultraviolet Spectroscopic Explorer Observations of a Supernova Remnant in the Line of Sight to HD 5980 in the Small Magellanic Cloud

We report a detection of far ultraviolet absorption from the supernova remnant SNR 0057 - 7226 in the Small Magellanic Cloud (SMC). The absorption is seen in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of the LBV/WR star HD 5980. Absorption from O VI 1032 and C III 977 is seen at a velocity of +300 km/s with respect to the Galactic absorption lines, +170 km/s with respect to the SMC absorption. The O VI 1038 line is contaminated by H_2 absorption, but is present. These lines are not seen in the FUSE spectrum of Sk80, only ~1' (~17 pc) away from HD 5980. No blue-shifted O VI 1032 absorption from the SNR is seen in the FUSE spectrum. The O VI 1032 line in the SNR is well described by a Gaussian with FWHM=75 km/s. We find log N(O VI)=14.33-14.43, which is roughly 50% of the rest of the O VI column in the SMC (excluding the SNR) and greater than the O VI column in the Milky Way halo along this sight line. The N(C IV)/N(O VI) ratio for the SNR absorption is in the range of 0.12-0.17, similar to the value seen in the Milky Way disk, and lower than the halo value, supporting models in which SNRs produce the highly ionized gas close to the plane of the Galaxy, while other mechanisms occur in the halo. The N(C IV)/N(O VI) ratio is also lower than the SMC ratio along this sight line, suggesting that other mechanisms contribute to the creation of the global hot ionized medium in the SMC. The O VI, C IV, and Si IV apparent column density profiles suggest the presence of a multi-phase shell followed by a region of higher temperature gas.Comment: 7 pages, 3 figures, 2 tables, uses emulateapj5.sty. Accepted for publication in ApJ Letter

Remote sensing in the mixing zone

Characteristics of dispersion and diffusion as the mechanisms by which pollutants are transported in natural river courses were studied with the view of providing additional data for the establishment of water quality guidelines and effluent outfall design protocols. Work has been divided into four basic categories which are directed at the basic goal of developing relationships which will permit the estimation of the nature and extent of the mixing zone as a function of those variables which characterize the outfall structure, the effluent, and the river, as well as climatological conditions. The four basic categories of effort are: (1) the development of mathematical models; (2) laboratory studies of physical models; (3) field surveys involving ground and aerial sensing; and (4) correlation between aerial photographic imagery and mixing zone characteristics

Discovery of a Nearby Low-Surface-Brightness Spiral Galaxy

During the course of a search for compact, isolated gas clouds moving with anomalous velocities in or near our own Galaxy (Braun and Burton 1998 A&A, in press), we have discovered, in the data of the Leiden/Dwingeloo survey (Hartmann and Burton 1997, Atlas of Galactic Neutral Hydrogen, CUP) of Galactic hydrogen, the HI signature of a large galaxy, moving at a recession velocity of 282 km/s, with respect to our Galaxy. Deep multicolor and spectroscopic optical observations show the presence of star formation in scattered HII regions; radio HI synthesis interferometry confirms that the galaxy is rich in HI and has the rotation signature of a spiral galaxy; a submillimeter observation failed to detect the CO molecule. The radio and optical evidence combined suggest its classification as a low-surface-brightness spiral galaxy. It is located in close spatial and kinematic proximity to the galaxy NGC 6946. The newly-discovered galaxy, which we call Cepheus 1, is at a distance of about 6 Mpc. It is probably to be numbered amongst the nearest few LSB spirals.Comment: 13 page LaTeX, requires aastex, 4 GIF figures. Accepted for publication in the AJ, January 199

Feedback in the local LBG Analog Haro 11 as probed by far-UV and X-ray observations

We have re-analyzed FUSE data and obtained new Chandra observations of Haro 11, a local (D_L=88 Mpc) UV luminous galaxy. Haro 11 has a similar far-UV luminosity (10^10.3 L_\odot), UV surface brightness (10^9.4 L_\odot kpc^-2), SFR, and metallicity to that observed in Lyman Break Galaxies (LBGs). We show that Haro 11 has extended, soft thermal (kT~0.68 keV) X-ray emission with a luminosity and size which scales with the physical properties (e.g. SFR, stellar mass) of the host galaxy. An enhanced alpha/Fe, ratio of ~4 relative to solar abundance suggests significant supernovae enrichment. These results are consistent with the X-ray emission being produced in a shock between a supernovae driven outflow and the ambient material. The FUV spectra show strong absorption lines similar to those observed in LBG spectra. A blueshifted absorption component is identified as a wind outflowing at ~200-280 km/s. OVI\lambda\lambda1032,1038 emission, the dominant cooling mechanism for coronal gas at T~10^5.5 K is also observed. If associated with the outflow, the luminosity of the OVI emission suggests that <20% of the total mechanical energy from the supernovae and solar winds is being radiated away. This implies that radiative cooling through OVI is not significantly inhibiting the growth of the outflowing gas. In contradiction to the findings of Bergvall et al 2006, we find no convincing evidence of Lyman continuum leakage in Haro 11. We conclude that the wind has not created a `tunnel' allowing the escape of a significant fraction of Lyman continuum photons and place a limit on the escape fraction of f_{esc}<2%. Overall, both Haro 11 and a previously observed LBG analogue VV 114, provide an invaluable insight into the X-ray and FUV properties of high redshift LBGs.Comment: Accepted for publication in ApJ, 40 pages, 17 figure

Library Services: Impact Analysis Spring 2018 to Fall 2018

Libraries are an essential element of learning on university campuses. The content housed within libraries supports academic exploration and growth. Physically, libraries are designed to provide access to materials and spaces that facilitate learning. This report explored the impact of student library resource use on student persistence to the next term. Students\u27 library resource use was captured with EZ Proxy log-ins and library material check-outs. Students who had a record of using library resources were compared to similar students who did not have a record of library resource use. They were compared using prediction-based propensity score matching. Students who used library resources were matched with non-users based on their persistence prediction and their propensity to participate. Students were 98% similar following matching. Participating and com­parison students were compared using difference-in-difference testing. Those who accessed library resources were significantly more likely to persist at USU than similar students who did not use library resources (DID = 0.017, p \u3c .001). The unstandardized effect size can be estimated through student impact. It is estimated that library resources assisted in retaining 278 (CI: 168 – 387) students each year who were otherwise not expected to persist