The SLUGGS Survey: kinematics for over 2500 globular clusters in twelve early-type galaxies

We present a spectrophotometric survey of 2522 extragalactic globular clusters (GCs) around 12 early-type galaxies, nine of which have not been published previously. Combining space-based and multicolour wide-field ground-based imaging, with spectra from the Keck/DEep Imaging Multi-Object Spectrograph (DEIMOS) instrument, we obtain an average of 160 GC radial velocities per galaxy, with a high-velocity precision of ∼15 km s−1 per GC. After studying the photometric properties of the GC systems, such as their spatial and colour distributions, we focus on the kinematics of metal-poor (blue) and metal-rich (red) GC subpopulations to an average distance of ∼8 effective radii from the galaxy centre. Our results show that for some systems the bimodality in GC colour is also present in GC kinematics. The kinematics of the red GC subpopulations are strongly coupled with the host galaxy stellar kinematics. The blue GC subpopulations are more dominated by random motions, especially in the outer regions, and decoupled from the red GCs. Peculiar GC kinematic profiles are seen in some galaxies: the blue GCs in NGC 821 rotate along the galaxy minor axis, whereas the GC system of the lenticular galaxy NGC 7457 appears to be strongly rotation supported in the outer region. We supplement our galaxy sample with data from the literature and carry out a number of tests to study the kinematic differences between the two GC subpopulations. We confirm that the GC kinematics are coupled with the host galaxy properties and find that the velocity kurtosis and the slope of their velocity dispersion profiles are different between the two GC subpopulations in more massive galaxies

Analysis of MCDM methods output coherence in oil and gas portfolio prioritization

Abstract This research paper aims at developing a triplex multi-criteria decision model to achieve an optimum allocation of resources to a portfolio of oilfields based on a number of criteria that pertain to the oilfields’ technical and contextual characteristics. It also offers an approach for validating the prioritization results generated by the methods used through a two-dimensional test that compares the internal and external prioritization stability of three multi-criteria decision making (MCDM) methods against a conventional Intuitive approach. The MCDM methods used include Analytic Hierarchy Process (AHP), Preference Ranking Organization METHod for Enriched Evaluation (PROMETHEE), and Technique of Order Preference Similarity to the Ideal Solution (TOPSIS). The internal and external consistency testing results are outlined in nine possible scenarios through which a conclusion is derived confirming the competitive advantage of MCDM methods