Mass Density Profiles of LSB Galaxies

We derive the mass density profiles of dark matter halos that are implied by high spatial resolution rotation curves of low surface brightness galaxies. We find that at small radii, the mass density distribution is dominated by a nearly constant density core with a core radius of a few kpc. For rho(r) ~ r^a, the distribution of inner slopes a is strongly peaked around a = -0.2. This is significantly shallower than the cuspy a < -1 halos found in CDM simulations. While the observed distribution of alpha does have a tail towards such extreme values, the derived value of alpha is found to depend on the spatial resolution of the rotation curves: a ~ -1 is found only for the least well resolved galaxies. Even for these galaxies, our data are also consistent with constant density cores (a = 0) of modest (~ 1 kpc) core radius, which can give the illusion of steep cusps when insufficiently resolved. Consequently, there is no clear evidence for a cuspy halo in any of the low surface brightness galaxies observed.Comment: To be published in ApJ Letters. 6 pages. Uses aastex and emulateapj5.sty Typo in Eq 1 fixe

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

A search for Low Surface Brightness galaxies in the near-infrared I. Selection of the sample

A sample of about 3,800 Low Surface Brightness (LSB) galaxies was selected using the all-sky near-infrared (J, H and K_s-band) 2MASS survey. The selected objects have a mean central surface brightness within a 5 arcsec radius around their centre fainter than 18 mag/sq.arcsec in the K_s band, making them the lowest surface brightness galaxies detected by 2MASS. A description is given of the relevant properties of the 2MASS survey and the LSB galaxy selection procedure, as well as of basic photometric properties of the selected objects. The latter properties are compared to those of other samples of galaxies, of both LSBs and `classical' high surface brightness (HSB) objects, which were selected in the optical. The 2MASS LSBs have a (B_T_c)-(K_T) colour which is on average 0.9 mag bluer than that of HSBs from the NGC. The 2MASS sample does not appear to contain a significant population of red objects.Comment: accepted for publication in Astronomy and Astrophysics on 24/2/2003; 62 page

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

A Morphological-type dependence in the mu_0-log(h) plane of Spiral galaxy disks

We present observational evidence for a galaxy `Type' dependence to the location of a spiral galaxy's disk parameters in the mu_0-log(h) (central disk surface-brightness - disk scale-length) plane. With a sample of ~40 Low Surface Brightness galaxies (both bulge- and disk-dominated) and ~80 High Surface Brightness galaxies, the early-type disk galaxies (<=Sc) tend to define a bright envelope in the mu_0-log(h) plane, while the late-type (>=Scd) spiral galaxies have, in general, smaller and fainter disks. Below the defining surface brightness threshold for a Low Surface Brightness galaxy (i.e. more than 1 mag fainter than the 21.65 B-mag arcsec^(-2) Freeman value), the early-type spiral galaxies have scale-lengths greater than 8-9 kpc, while the late-type spiral galaxies have smaller scale-lengths. All galaxies have been modelled with a seeing-convolved Sersic r^(1/n) bulge and exponential disk model. We show that the trend of decreasing bulge shape parameter (n) with increasing Hubble type and decreasing bulge-to-disk luminosity ratio, which has been observed amongst the High Surface Brightness galaxies, extends to the Low Surface Brightness galaxies, revealing a continuous range of structural parameters.Comment: To be published in ApJ. Inc. three two-part figure

A Structural and Dynamical Study of Late-Type, Edge-On Galaxies: I. Sample Selection and Imaging Data

We present optical (B & R) and infrared (K_s) images and photometry for a sample of 49 extremely late-type, edge-on disk galaxies selected from the Flat Galaxy Catalog of Karenchentsev et al. (1993). Our sample was selected to include galaxies with particularly large axial ratios, increading the likelihood that the galaxies in the sample are truly edge-on. We have also concentrated the sample on galaxies with low apparent surface brightness, in order to increase the representation of intrinisically low surface brightness galaxies. Finally, the sample was chosen to have no apprarent bulges or optical warps so that the galaxies represent undisturbed, ``pure disk'' systems. The resulting sample forms the basis for a much larger spectroscopic study designed to place constraints on the physical quantities and processes which shape disk galaxies. The imaging data presented in this paper has been painstakingly reduced and calibrated to allow accurate surface photometry of features as faint as 30 mag/sqr-arcsec in B and 29 mag/sqr-arcsec in R on scales larger than 10 arcsec. Due to limitations in sky subtraction and flat fielding, the infrared data can reach only to 22.5 mag/sqr-arcsec in K_s on comparable scales. As part of this work, we have developed a new method for quantifying the reliability of surface photometry, which provides useful diagnostics for the presence of scattered light, optical emission from infrared cirrus, and other sources of non-uniform sky backgrounds.Comment: scheduled to appear in the Astronomical Journal, LaTeX, 36 pages including 7 pages of figures (fig 1-2,4). A low resolution version of Figure 3 is included in JPEG format; contours are seriously degraded. A full resolution Postscript version of Figure 3 (10.6Mb,gzipped) is available through anonymous ftp at ftp://ftp.astro.washington.edu/pub/users/jd/FGC/dalcanton.f3.ps.g