The bimodal spiral galaxy surface brightness distribution

We have assessed the significance of Tully and Verheijen's (1997) bimodal Ursa Major Cluster spiral galaxy near-infrared surface brightness distribution, focussing on whether this bimodality is simply an artifact of small number statistics. A Kolmogorov-Smirnov style of significance test shows that the total distribution is fairly represented by a single-peaked distribution, but that their isolated galaxy subsample (with no significant neighbours within a projected distance of around 80 kpc) is bimodal at the 96 per cent level. We have also investigated the assumptions underlying the isolated galaxy surface brightness distribution, finding that the (often large) inclination corrections used in the construction of this distribution reduce the significance of the bimodality. We conclude that the Ursa Major Cluster dataset is insufficient to establish the presence of a bimodal near-infrared surface brightness distribution: an independent sample of around 100 isolated, low inclination galaxies is required to establish bimodality at the 99 per cent level.Comment: 5 pages LaTeX; 2 embedded figures; re-submitted to MNRAS after replying to referee's comment

A High-Resolution Rotation Curve of NGC 6822: A Test-case for Cold Dark Matter

We present high resolution rotation curves of the local group dwarf irregular galaxy NGC 6822 obtained with the Australia Telescope Compact Array. Our best curves have an angular resolution of 8'' or 20 pc and contain some 250 independent points. The stellar and gas components of NGC 6822 cannot explain the shape of the curve, except for the very inner regions, and NGC 6822 is consequently very dark matter dominated. There is no evidence for the presence of a steep density cusp down to scales of ~20 pc, contrary to the predictions of Cold Dark Matter.Comment: Accepted for publication in MNRA

Two-body hadronic charmed meson decays

We study in this work the two-body hadronic charmed meson decays, including both the PP and VP modes. The latest experimental data are first analyzed in the diagrammatic approach. The magnitudes and strong phases of the flavor amplitudes are extracted from the Cabibbo-favored (CF) decay modes using $\chi^2$ minimization. The best-fitted values are then used to predict the branching fractions of the singly-Cabibbo-suppressed (SCS) and doubly-Cabibbo-suppressed decay modes in the flavor SU(3) symmetry limit. We observe significant SU(3) breaking effects in some of SCS channels. In the case of VP modes, we point out that the $A_P$ and $A_V$ amplitudes cannot be completely determined based on currently available data. We conjecture that the quoted experimental results for both $D_s^+\to\bar K^0K^{*+}$ and $D_s^+\to \rho^+\eta'$ are overestimated. We compare the sizes of color-allowed and color-suppressed tree amplitudes extracted from the diagrammatical approach with the effective parameters $a_1$ and $a_2$ defined in the factorization approach. The ratio $|a_2/a_1|$ is more or less universal among the $D \to {\bar K} \pi$, ${\bar K}^* \pi$ and ${\bar K} \rho$ modes. This feature allows us to discriminate between different solutions of topological amplitudes. For the long-standing puzzle about the ratio $\Gamma(D^0\to K^+K^-)/\Gamma(D^0\to\pi^+\pi^-)$, we argue that, in addition to the SU(3) breaking effect in the spectator amplitudes, the long-distance resonant contribution through the nearby resonance $f_0(1710)$ can naturally explain why $D^0$ decays more copiously to $K^+ K^-$ than $\pi^+ \pi^-$ through the $W$-exchange topology.Comment: 32 pages, 5 figures. An alternative method for error bar extraction is used; last columns of Tables~I to VI, and all entries in Tables~VII, VIII and X are modified. To appear in PRD

The First CO Map of a Low Surface Brightness Galaxy

Using the Owens Valley Radio Observatory Millimeter-Wavelength Array (OVRO) we have obtained the first CO map of a low surface brightness (LSB) galaxy. The studied galaxy, UGC 01922, was chosen for these observations because both of its previous CO detection with the IRAM 30m telescope and its classification as a Malin 1 `cousin' - an LSB galaxy with M_HI > 10^10 Msol. The OVRO map detected approximately 65% of the CO(1-0) flux found earlier with the single dish measurements, giving a detected gas mass equivalent to M_H2 = 1.1X10^9 Msol. The integrated gas peak lies at the center of the galaxy and coincides with both the optical and 1.4 GHz continuum emission peaks. The molecular gas extends well beyond the OVRO beam size (~4'' or 3 kpc), covering ~25% of the optical bulge. In all, perhaps the most remarkable aspect of this map is its unexceptional appearance. Given that it took over ten years to successfully detect molecular gas in any low surface brightness system, it is surprising that the appearance and distribution of UGC 01922's CO is similar to what would be expected for a high surface brightness galaxy in the same morphological class.Comment: 5 pages, including 3 figures and 3 tables. also available online at http://www.gb.nrao.edu/~koneil. Accepted by ApJ

Coordinating criminal justice: a Qualitative Comparative Analysis of inter-organisational information sharing of four EU Member States

Qualitative-comparative analysis of four cases of inter-organisational information sharing in criminal justice chains demonstrates the causal asymmetry between successful and unsuccessful inter-organisational information sharing. While unsuccessful information sharing requires poor project management, successful information sharing also requires compatible technologies which are implemented either by means of a small-scale, bottom-up approach to standardization or a top-down, centralised architecture. By triggering the radical restructuring of information-sharing workflows, good project management and compatible technologies set in motion underlying mechanisms that generate successful inter-organisational information sharing. Implications are discussed by highlighting the role of coordination by technological feedback in a context of increasing digitization

Digitizing criminal justice: A Qualitative Comparative Analysis of supply-chain integration across four EU Member States

Drawing on Qualitative Comparative Analysis (QCA) techniques, we formally analyse four cases of supply-chain integration within the European Union (EU). Our findings demonstrate the causal asymmetry between successful and unsuccessful digitization of inter-organizational information flows. While unsuccessful digitization requires poor project management skills, successful digitization is much more demanding because it also requires compatible technologies which are implemented either by means of a small-scale, bottom-up approach to standardization or a single, centralised architecture developed in a top-down fashion. Theoretical and practical implications are discussed by highlighting the key role of coordination by feedback in a context of increasing digitization of criminal justice systems

Further Discoveries of 12CO in Low Surface Brightness Galaxies

Using the IRAM 30m telescope we have obtained seven new, deep CO J(1-0) and J(2-1) observations of low surface brightness (LSB) galaxies. Five of the galaxies have no CO detected to extremely low limits (0.1-0.4 K km/s at J(1-0)), while two of the galaxies, UGC 01922 and UGC 12289, have clear detections in both line transitions. When these observations are combined with all previous CO observations taken of LSB systems, we compile a total of 34 observations, in which only 3 galaxies have had detections of their molecular gas. Comparing the LSB galaxies with and without CO detections to a sample of high surface brightness (HSB) galaxies with CO observations indicates that it is primarily the low density of baryonic matter within LSB galaxies which is causing their low CO fluxes. Finally, we note that one of the massive LSB galaxies studied in this project, UGC 06968 (a Malin-1 `cousin'), has upper limits placed on both M_H2 and M_H2/M_HI which are 10-20 times lower than the lowest values found for any galaxy (LSB or HSB) with similar global properties. This may be due to an extremely low temperature and metallicity within UGC 06968, or simply due to the CO distribution within the galaxy being too diffuse to be detected by the IRAM beam.Comment: 18 pages, 8 figures, 4 tables. Accepted by Ap

Electromagnetic superconductivity of vacuum induced by strong magnetic field: numerical evidence in lattice gauge theory

Using numerical simulations of quenched SU(2) gauge theory we demonstrate that an external magnetic field leads to spontaneous generation of quark condensates with quantum numbers of electrically charged rho mesons if the strength of the magnetic field exceeds the critical value eBc = 0.927(77) GeV^2 or Bc =(1.56 \pm 0.13) 10^{16} Tesla. The condensation of the charged rho mesons in strong magnetic field is a key feature of the magnetic-field-induced electromagnetic superconductivity of the vacuum.Comment: 14 pages, 5 figures, 2 tables, elsarticle style; continuum limit is analyzed, best fit parameters are presented in Table 2, published versio