751 research outputs found

    Recognition of Rhodesia and Traditional International Law: Some Conceptual Problems

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    The traditional theories of recognition do not properly maintain the essential distinction between state and government. The only proper way to maintain this distinction is by laying down verifiable criteria for statehood, and treating the recognition of governments as purely discretionary. A state must have come into existence before the question of recognition of a particular government can arise. International personality is a consequence of statehood, not of recognition; if a state can objectively come into existence, so can international personality, and the grant or withdrawal of recognition cannot affect that personality. The degree of recognition conferred by the United Kingdom and other countries on Rhodesia on various occasions was limited in scope, purpose, and time, and was not indicative of any opinion that the Smith government or the Smith/Muzorewa government was the legitimate government of Rhodesia; nor did such qualified recognition demonstrate any intention to have normal relations with Rhodesia. It would seem proper to view this as a question of recognition of a de facto governing authority. Rhodesia must, therefore, be regarded as a state with international legal personality. As such, it is bound by international law, like any other state, and is subject to the usual range of penal sanctions available to the international community to counter any breach of international law

    Accounting for the foreground contribution to the dust emission towards Kepler's supernova remnant

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2009.15061.xWhether or not supernovae contribute significantly to the overall dust budget is a controversial subject. Submillimetre (sub-mm) observations, sensitive to cold dust, have shown an excess at 450 and 850 ÎŒm in young remnants Cassiopeia A (Cas A) and Kepler. Some of the sub-mm emission from Cas A has been shown to be contaminated by unrelated material along the line of sight. In this paper, we explore the emission from material towards Kepler using sub-mm continuum imaging and spectroscopic observations of atomic and molecular gas, via H i, 12CO(J= 2–1) and 13CO(J= 2–1). We detect weak CO emission (peak T*A = 0.2–1 K, 1–2 km s−1 full width at half-maximum) from diffuse, optically thin gas at the locations of some of the sub-mm clumps. The contribution to the sub-mm emission from foreground molecular and atomic clouds is negligible. The revised dust mass for Kepler's remnant is 0.1–1.2 M⊙ , about half of the quoted values in the original study by Morgan et al., but still sufficient to explain the origin of dust at high redshifts.Peer reviewe

    Radio Observations of Infrared Luminous High Redshift QSOs

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    We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al. (2001). We detect seven sources at 1.4 GHz with flux densities, S_{1.4} > 50 microJy. These centimeter (cm) wavelength observations imply that the millimeter (mm) emission is most likely thermal dust emission. The radio-through-optical spectral energy distributions for these sources are within the broad range defined by lower redshift, lower optical luminosity QSOs. For two sources the radio continuum luminosities and morphologies indicate steep spectrum, radio loud emission from a jet-driven radio source. For the remaining 10 sources the 1.4 GHz flux densities, or limits, are consistent with those expected for active star forming galaxies. If the radio emission is powered by star formation in these systems, then the implied star formation rates are of order 1e3 M_solar/year. We discuss the angular sizes and spatial distributions of the radio emitting regions, and we consider briefly these results in the context of co-eval black hole and stellar bulge formation in galaxies.Comment: to appear in the A

    The Radio-to-Submm Spectral Index as a Redshift Indicator

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    We present models of the 1.4 GHz to 350 GHz spectral index, alpha(350/1.4), for starburst galaxies as a function of redshift. The models include a semi-analytic formulation, based on the well quantified radio-to-far infrared correlation for low redshift star forming galaxies, and an empirical formulation, based on the observed spectrum of the starburst galaxies M82 and Arp 220. We compare the models to the observed values of alpha(350/1.4) for starburst galaxies at low and high redshift. We find reasonable agreement between the models and the observations, and in particular, that an observed spectral index of alpha(350/1.4) > +0.5 indicates that the target source is likely to be at high redshift, z > 1. The evolution of alpha(350/1.4) with redshift is mainly due to the very steep rise in the Raleigh-Jeans portion of the thermal dust spectrum shifting into the 350 GHz band with increasing redshift. We also discuss situations where this relationship could be violated. We then apply our models to examine the putative identifications of submm sources in the Hubble Deep Field, and conclude that the submm sources reported by Hughes et al. are likely to be at high redshifts, z > 1.5.Comment: standard LATEX file plus 1 postscript figure. Added references and revised figure. second figure revision. Final Proof version. to appear in Astrophysical Journal Letter

    A Search for Dense Molecular Gas in High Redshift Infrared-Luminous Galaxies

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    We present a search for HCN emission from four high redshift far infrared (IR) luminous galaxies. Current data and models suggest that these high zz IR luminous galaxies represent a major starburst phase in the formation of spheroidal galaxies, although many of the sources also host luminous active galactic nuclei (AGN), such that a contribution to the dust heating by the AGN cannot be precluded. HCN emission is a star formation indicator, tracing dense molecular hydrogen gas within star-forming molecular clouds (n(H2_2) ∌105\sim 10^5 cm−3^{-3}). HCN luminosity is linearly correlated with IR luminosity for low redshift galaxies, unlike CO emission which can also trace gas at much lower density. We report a marginal detection of HCN (1-0) emission from the z=2.5832z=2.5832 QSO J1409+5628, with a velocity integrated line luminosity of LHCNâ€Č=6.7±2.2×109L_{\rm HCN}'=6.7\pm2.2 \times10^{9} K km s−1^{-1} pc2^2, while we obtain 3σ\sigma upper limits to the HCN luminosity of the z=3.200z=3.200 QSO J0751+2716 of LHCNâ€Č=1.0×109L_{\rm HCN}'=1.0\times10^{9} K km s−1^{-1} pc2^2, LHCNâ€Č=1.6×109L_{\rm HCN}'=1.6\times10^{9} K km s−1^{-1} pc2^2 for the z=2.565z= 2.565 starburst galaxy J1401+0252, and LHCNâ€Č=1.0×1010L_{\rm HCN}'=1.0\times10^{10} K km s−1^{-1} pc2^2 for the z=6.42z = 6.42 QSO J1148+5251. We compare the HCN data on these sources, plus three other high-zz IR luminous galaxies, to observations of lower redshift star-forming galaxies. The values of the HCN/far-IR luminosity ratios (or limits) for all the high zz sources are within the scatter of the relationship between HCN and far-IR emission for low zz star-forming galaxies (truncated).Comment: aastex format, 4 figures. to appear in the Astrophysical Journal; Revised lens magnification estimate for 1401+025

    Dense molecular gas in quasar host galaxies: a search for HCN emission from BR B1202-0725 at z=4.695

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    We report on the results of a search using the VLA for redshifted HCN(1-0) emission from the host galaxy of BR B1202-0725, an optically luminous quasar at z=4.695. The host galaxy emits strongly in the rest-frame far-infrared, and shows characteristics very similar to that of more local, ultraluminous infrared galaxies, in which a significant fraction of the far-infrared emission is powered by star formation. We find a 3-sigma upper limit to the HCN(1-0) emission of 4.9 x 10^10 K kms^-1 pc^2, assuming a lambda-cosmology. This limit is consistent with correlations derived from measurements of the HCN, CO, and far-infrared emission for a sample of more local galaxies, including starbursts (Solomon et al, 1992a)

    Mid-J CO Emission in Nearby Seyfert Galaxies

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    We study for the first time the complete sub-millimeter spectra (450 GHz to 1550 GHz) of a sample of nearby active galaxies observed with the SPIRE Fourier Transform Spectrometer (SPIRE/FTS) onboard Herschel. The CO ladder (from Jup = 4 to 12) is the most prominent spectral feature in this range. These CO lines probe warm molecular gas that can be heated by ultraviolet photons, shocks, or X-rays originated in the active galactic nucleus or in young star-forming regions. In these proceedings we investigate the physical origin of the CO emission using the averaged CO spectral line energy distribution (SLED) of six Seyfert galaxies. We use a radiative transfer model assuming an isothermal homogeneous medium to estimate the molecular gas conditions. We also compare this CO SLED with the predictions of photon and X-ray dominated region (PDR and XDR) models.Comment: Proceedings of the Torus Workshop 2012 held at the University of Texas at San Antonio, 5-7 December 2012. C. Packham, R. Mason, and A. Alonso-Herrero (eds.); 6 pages, 3 figure

    Assessing Religious Orientations: Replication and Validation of the Commitment-Reflectivity Circumplex (CRC) Model

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    The Commitment-Reflectivity Circumplex (CRC) model is a structural model of religious orientation that was designed to help organize and clarify measurement of foundational aspect of religiousness. The current study successfully replicated the CRC model using multidimensional scaling, and further evaluated the reliability, structure, and validity of their measures in both a university student sample (Study 1) and a nationally representative sample (Study 2). All 10 subscales of the Circumplex Religious Orientation Inventory (CROI) demonstrated good reliability across both samples. A two-week test-retest of the CROI showed that the subscales are stable over time. A confirmatory factor analysis of the CROI in the representative adult sample demonstrated good model fit. Finally, the CROI’s validity was examined in relation to the Intrinsic, Extrinsic and Quest measures. Overall, the CROI appears to clarify much of the ambiguity inherent in the established scales by breaking down what were very broad orientations into very specific suborientations. The results suggest that the CRC model is applicable for diverse populations of adults. In addition, the CROI appears to be construct valid with good structural and psychometric properties across all 10 subscales

    The applicability of FIR fine-structure lines as Star Formation Rate tracers over wide ranges of metallicities and galaxy types

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    We analyze the applicability of far-infrared fine-structure lines [CII] 158 micron, [OI] 63 micron and [OIII] 88 micron to reliably trace the star formation rate (SFR) in a sample of low-metallicity dwarf galaxies from the Herschel Dwarf Galaxy Survey and compare with a broad sample of galaxies of various types and metallicities in the literature. We study the trends and scatter in the relation between the SFR (as traced by GALEX FUV and MIPS 24 micron) and far-infrared line emission, on spatially resolved and global galaxy scales, in dwarf galaxies. We assemble far-infrared line measurements from the literature and infer whether the far-infrared lines can probe the SFR (as traced by the total-infrared luminosity) in a variety of galaxy populations. In metal-poor dwarfs, the [OI] and [OIII] lines show the strongest correlation with the SFR with an uncertainty on the SFR estimates better than a factor of 2, while the link between [CII] emission and the SFR is more dispersed (uncertainty factor of 2.6). The increased scatter in the SFR-L([CII]) relation towards low metal abundances, warm dust temperatures, large filling factors of diffuse, highly ionized gas suggests that other cooling lines start to dominate depending on the density and ionization state of the gas. For the literature sample, we evaluate the correlations for a number of different galaxy populations. The [CII] and [OI] lines are considered to be reliable SFR tracers in starburst galaxies, recovering the star formation activity within an uncertainty of factor 2. [Abridged]Comment: 35 pages, 13 figures, accepted for publication in A&A on May 7th 201
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