Hydrodynamical simulations of colliding jets:modeling 3C 75

Radio observations suggest that 3C 75, located in the dumbbell shaped galaxy NGC 1128 at the center of Abell 400, hosts two colliding jets. Motivated by this source, we perform three-dimensional hydrodynamical simulations using a modified version of the GPU-accelerated Adaptive-MEsh-Refinement hydrodynamical parallel code ($\mathit{GAMER}$) to study colliding extragalactic jets. We find that colliding jets can be cast into two categories: 1) bouncing jets, in which case the jets bounce off each other keeping their identities, and 2) merging jets, when only one jet emerges from the collision. Under some conditions the interaction causes the jets to break up into oscillating filaments of opposite helicity, with consequences for their downstream stability. When one jet is significantly faster than the other and the impact parameter is small, the jets merge; the faster jet takes over the slower one. In the case of merging jets, the oscillations of the filaments, in projection, may show a feature which resembles a double helix, similar to the radio image of 3C 75. Thus we interpret the morphology of 3C 75 as a consequence of the collision of two jets with distinctly different speeds at a small impact parameter, with the faster jet breaking up into two oscillating filaments.Comment: 13 pages, 9 figures, accepted for publication in Ap

AMiBA: Array for Microwave Background Anisotropy

As part of a 4-year Cosmology and Particle Astrophysics (CosPA) Research Excellence Initiative in Taiwan, AMiBA $-$ a 19-element dual-channel 85-105 GHz interferometer array is being specifically built to search for high redshift clusters of galaxies via the Sunyaev-Zeldovich Effect (SZE). In addition, AMiBA will have full polarization capabilities, in order to probe the polarization properties of the Cosmic Microwave Background. AMiBA, to be sited on Mauna Kea in Hawaii or in Chile, will reach a sensitivity of $\sim 1$ mJy or 7$\mu$K in 1 hour. The project involves extensive international scientific and technical collaborations. The construction of AMiBA is scheduled to starting operating in early 2004.Comment: Contribution to IAU Symposium 201, `New Cosmological Data and the Values of the Fundamental Parameters', eds. A Lasenby and A Wilkinson; 6 pages including 2 figures. Also available form the AMiBA website at http://www.asiaa.sinica.edu.tw/amiba/papers/iauamiba.tar.gz. Minor corrections in text

Can We Detect the Color–Density Relation with Photometric Redshifts?

A variety of methods have been proposed to define and to quantify galaxy environments. While these techniques work well in general with spectroscopic redshift samples, their application to photometric redshift surveys remains uncertain. To investigate whether galaxy environments can be robustly measured with photo-z samples, we quantify how the density measured with the nearest-neighbor approach is affected by photo-z uncertainties by using the Durham mock galaxy catalogs in which the 3D real-space environments and the properties of galaxies are known exactly. Furthermore, we present an optimization scheme in the choice of parameters used in the 2D projected measurements that yield the tightest correlation with respect to the 3D real-space environments. By adopting the optimized parameters in the density measurements, we show that the correlation between the 2D projected optimized density and the real-space density can still be revealed, and the color–density relation is also visible out to z ~ 0.8 even for a photo-z uncertainty (${\sigma }_{{{\rm{\Delta }}}_{z}/(1+z)}$) up to 0.06. We find that at redshifts 0.3 < z < 0.5 a deep (i ~ 25) photometric redshift survey with ${\sigma }_{{{\rm{\Delta }}}_{z}/(1+z)}\;=\;0.02$ yields a performance in small-scale density measurement that is comparable to a shallower i ~ 22.5 spectroscopic sample with ~10% sampling rate. Finally, we discuss the application of the local density measurements to the Pan-STARRS1 Medium Deep Survey (PS-MDS), one of the largest deep optical imaging surveys. Using data from ~5 square degrees of survey area, our results show that it is possible to measure local density and to probe the color–density relation with 3σ confidence level out to z ~ 0.8 in the PS-MDS. The color–density relation, however, quickly degrades for data covering smaller areas

Problems of innovative receptivity of personnel of enterprises of industrial automation

Стаття присвячена аналізу галузі промислової автоматики (ПА), позначенню та з’ясовуванню проблематики у підприємств ПА для поліпшення інноваційної діяльності (ІД) шляхом комплексного підвищення інноваційної сприйнятливості (ІС) персоналу в системі управління персоналом. Показана динаміка виробничих економічних показників українських підприємств ПА за 2011-2017 рр., запропоновані рекомендації по підвищенню ІС персоналу. Наведено аналіз техніко-економічних показників підприємств ПА. Приведений загальний огляд реалізації продукції (товарів, послуг за видами економічної діяльності) на Україні за період 2010-2017 рр. Для дослідження приведена методологія порівняльного аналізу. Результати дослідження показують виявлення проблем підприємств ПA, які полягають у збільшенні реалізованої продукції і зниженні прибутку, що говорить про необхідність підвищення IС персоналу в системі управління персоналом.The article is devoted to the analysis of industrial areas in particular the field of industrial automation (ІA), the identification and clarification of problems in PA enterprises, to improve innovation activity (IА) through a comprehensive increase in the innovative receptivity (IR) of personnel in the personnel management system. The industrial enterprises of Ukraine and in particular industry of ІА now experiences heavy times of competitive activity with foreign companies and in particular with more cheap commodities from China. Not to lose the positions and occupy new markets it is needed not only to watch after novelties in the field of productive but also in the sphere of personnel and increase of him ІR for the increase of competitiveness. The dynamics of the production of economic indicators of the Ukrainian enterprises of IA for 2011-2017 is shown, recommendations for increasing the executive personnel are offered. The analysis of technical and economic indicators of IA enterprises is given. And also provides a general overview of the sale of products (goods, services by type of economic activity) in Ukraine for the period 2010-2017. For research methodology over of comparative analysis is brought. Research results are exposures of problems of enterprises of IA such as an increase of the realized products and decline of profit, that talks at the necessity of increase of IR of personnel, in control system by a personnel. Innovative activity of every enterprise of industrial automation (IA) is important for the increase of competitiveness and increase arrived. The innovative oriented skilled personnel failing in the Ukrainian enterprises, what called to provide development and increase of efficiency of activity of enterprises. For development normatively of technical documentation on a management and development of personnel experience of front-rank world companies is poorly used what track is adapted to take into account taking into account Ukrainian realities. To the necessity of development of control system by a personnel with the purpose of leading to of them to the standards of front-rank world companies

Genotypic analysis of genes associated with transmission and drug resistance in the Beijing lineage of Mycobacterium tuberculosis

AbstractThe Beijing genotype of Mycobacterium tuberculosis is an endemic lineage in East Asia that has disseminated worldwide. It is a major health concern, as it is geographically widespread and is considered to be hypervirulent. To elucidate its genetic diversity in Taiwan, phylogenetic reconstruction was performed using 338 M. tuberculosis Beijing family clinical isolates. Region-of-difference analysis revealed the strains from Taiwan to be distributed among six subgroups of a phylogenetic tree. Synonymous single nucleotide polymorphisms at 10 chromosomal positions were also analysed. Among the 338 isolates analysed for single-nucleotide polymorphisms by using mass spectrometry, the most frequent strain found was ST10 (53.3%), followed by ST19 (14.8%) and ST22 (14.5%). Tests of drug resistance showed that the sublineages ST10, ST19 and ST26 were over-represented in the multidrug-resistant population. The presence of mutations in putative genes coding for DNA repair enzymes, which could confer a mutator phenotype to facilitate spreading of the pathogen, did not demonstrate an association with multidrug resistance. Therefore, the DNA repair genes may be involved in transmission but not in drug resistance

Deep Wide-Field Spectrophotometry of the Open Cluster M67

We present nine color CCD intermediate-band spectrophotometry of a two square degree field centered on the old open cluster M67, from 3890$\rm \AA$ to nearly 1$\mu$. These observations are taken as a part of the BATC (Beijing-Arizona-Taipei-Connecticut) Color Survey of the Sky, for both scientific and calibration reasons. With these data we show that the BATC survey can reach its goal of obtaining spectrophotometry to a zero point accuracy of 0.01 mag, and down to V = 21 with 0.3 mag random error. We fit the color-magnitude diagrams (CMDs) with Worthey's theoretical models. The net result is the excellent fit of the 4.0 Gyr, [Fe/H] = $-0.10$ model to our data, including a good fit to the main sequence (MS) turn-off. Our data are consistent with a toy model with 50\% of the stars in M67 being binaries and a random distribution of binary mass-ratios, although other models with different mass-ratio distributions cannot be ruled out. The spatial distribution and mass function (MF) of stars in M67 show marked effects of dynamical evolution and evaporation of stars from the cluster. Blue stragglers and binary stars are the most condensed within the cluster, with degree of condensation depending on mass.We find M67 to have an elongated shape, oriented at an angle of $15^{\circ}$ relative to the galactic plane. Within its tidal radius, the observed MF of M67 between 1.2 $\rm M_\odot$ and $\rm 0.8 M_\odot$ has a Salpeter slope $\rm \eta = -1.93 \pm 0.66$. For stars of mass below 0.8 $\rm M_\odot$, $\rm \eta \sim 0$. It is plausible that the leveling-off of the MF at lower masses is a result of evaporation of lower mass stars in this mass range at a rate of one every $\sim 10^7$ years. If so, it is plausible that the IMF of M67 has the canonical field value of $\rm \eta = -2.0$.Comment: 74 pages, including 19 ps figures. Accepted for publication in AJ, Aug, 199

Dynamic Evolution of a Quasi-Spherical General Polytropic Magnetofluid with Self-Gravity

In various astrophysical contexts, we analyze self-similar behaviours of magnetohydrodynamic (MHD) evolution of a quasi-spherical polytropic magnetized gas under self-gravity with the specific entropy conserved along streamlines. In particular, this MHD model analysis frees the scaling parameter $n$ in the conventional polytropic self-similar transformation from the constraint of $n+\gamma=2$ with $\gamma$ being the polytropic index and therefore substantially generalizes earlier analysis results on polytropic gas dynamics that has a constant specific entropy everywhere in space at all time. On the basis of the self-similar nonlinear MHD ordinary differential equations, we examine behaviours of the magnetosonic critical curves, the MHD shock conditions, and various asymptotic solutions. We then construct global semi-complete self-similar MHD solutions using a combination of analytical and numerical means and indicate plausible astrophysical applications of these magnetized flow solutions with or without MHD shocks.Comment: 21 pages, 7 figures, accepted for publication in APS

Isotopic Composition of Light Nuclei in Cosmic Rays: Results from AMS-01

The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper we present measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be) and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.Comment: To appear in ApJ. 12 pages, 11 figures, 6 table