431 research outputs found

    Evidence for a Non-Expanding Universe: Surface Brightness Data From HUDF

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    Surface brightness data can distinguish between a Friedman-Robertson-Walker expanding universe and a non-expanding universe. For surface brightness measured in AB magnitudes per angular area, all FRW models, regardless of cosmological parameters, predict that surface brightness declines with redshift as (z+1)^-3, while any non-expanding model predicts that surface brightness is constant with distance and thus with z. High-z UV surface brightness data for galaxies from the Hubble Ultra Deep Field and low-z data from GALEX are used to test the predictions of these two models up to z=6. A preliminary analysis presented here of samples observed at the same at-galaxy wavelengths in the UV shows that surface brightness is constant, mu=kz^0.026+-0.15, consistent with the non-expanding model. This relationship holds if distance is linearly proportional to z at all redshifts, but seems insensitive to the particular choice of d-z relationship. Attempts to reconcile the data with FRW predictions by assuming that high-z galaxies have intrinsically higher surface brightness than low-z galaxies appear to face insurmountable problems. The intrinsic FUV surface brightness required by the FRW models for high-z galaxies exceeds the maximum FUV surface brightness of any low-z galaxy by as much as a factor of 40. Dust absorption appears to make such extremely high intrinsic FUV surface brightness physically impossible. If confirmed by further analysis, the impossibility of such high-surface-brightness galaxies would rule out all FRW expanding universe (big bang) models.Comment: 16 pages, 9 figures, to be published in the Proceedings of the First Crisis in Cosmology Conference, AIP proceedings series typos correcte

    Do local analogs of Lyman Break Galaxies exist?

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    The optical properties of a number of supercompact ultraviolet luminous galaxies (UVLG), recently discovered in the local Universe matching GALEX and Sloan Digital Sky Survey (SDSS) data, are discussed. Detailed re-analysis of the SDSS data for these and other similar but nearer galaxies shows that their surface brightness radial profile in both R and u bands is in most cases well described by an extended disk plus a central unresolved component (possibly a bulge). Since the SDSS pipeline used a single disk component to derive the half light radius of these UVLGs their size was severely underestimated. Consequently, the average UV surface brightness is much lower that previously quoted casting doubts on the claim that UVLGs are the local analogs of high redshift Lyman break galaxies.Comment: Accepted for publication on the Astrophysical Journal, 10 pages, 5 figure

    Ship-based nitric acid measurements in the Gulf of Maine during New England Air Quality Study 2002

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    Gas phase nitric acid (HNO3) was measured at 5-min resolution on board the National Oceanographic and Atmospheric Administration (NOAA) research vessel Ronald H. Brown during the second leg (29 July to 10 August) of the New England Air Quality Study (NEAQS) 2002 cruise. A primary objective of the cruise was to improve understanding of the oxidation of NOx in, and removal of the oxidation products from, the polluted marine boundary layer east of northeastern North America. For the first 9 days of this leg the ship remained north of Cape Cod, and the cruise track did not extend much farther north than the New Hampshire-Maine border. During this period, HNO3 averaged 1.1 ppb and accounted for 19% of total reactive nitrogen oxides (measured NOy). On all days, peak HNO3 mixing ratios were observed in the early afternoon (average 2.3 ppb), at levels twofold to fourfold higher than the minima around sunrise and sunset. In these daytime peaks, HNO3/NOy averaged 28%. There were secondary nighttime peaks of HNO3 (0.9 ppb average), when HNO3 accounted for 16% of total reactive nitrogen oxides. This pronounced diurnal pattern confirms that production, and subsequent deposition, of HNO3 in the polluted marine boundary layer downwind of New England removes a significant fraction of the NOx exported to the atmosphere over the Gulf of Maine. Nitric acid was correlated with O3, particularly during the early afternoon interval when both molecules reached maximum mixing ratios (R2 = 0.66). The ozone production efficiency (OPE) inferred from the slope (10 ppb O3/ppb HNO3) was similar to the OPE of 9 estimated at the Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) Thompson Farm station in coastal New Hampshire during the study period

    Viscous and induced current heating in plasma focus plasmoids

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    Recently, Abolhasani et al, proposed that the high ion energies observed in plasmoids formed in the plasma focus could be explained by viscous heating. We here elaborate this proposal, demonstrating that during plasmoid formation, ion motion along magnetic field lines can be rapidly converted, at least in part, to thermal energy through viscous diffusion. This effect is strongly enhanced by higher-z ions. We compare the theoretical predictions with the recent observation by Lerner et al, of trapped ion energies of 160 keV. In addition, we propose a second source of heating. The mildly relativistic electron beam emitted by the plasmoid, generates an induced current within the plasmoid comparable to the beam current and confined to approximately the same region. The induced current electrons, with drift velocity vd

    Senior Recital: Aidan Lerner, clarinet

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    This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Music Education. Mr. Lerner studies clarinet with John Warren.https://digitalcommons.kennesaw.edu/musicprograms/2324/thumbnail.jp
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