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

AEGIS: Enhancement of Dust-enshrouded Star Formation in Close Galaxy Pairs and Merging Galaxies up to z ~ 1

Using data from the DEEP2 Galaxy Redshift Survey and HST/ACS imaging in the Extended Groth Strip, we select nearly 100 interacting galaxy systems including kinematic close pairs and morphologically identified merging galaxies. Spitzer MIPS 24 micron fluxes of these systems reflect the current dusty star formation activity, and at a fixed stellar mass (M_{*}) the median infrared luminosity (L_{IR}) among merging galaxies and close pairs of blue galaxies is twice (1.9 +/- 0.4) that of control pairs drawn from isolated blue galaxies. Enhancement declines with galaxy separation, being strongest in close pairs and mergers and weaker in wide pairs compared to the control sample. At z ~ 0.9, 7.1% +/- 4.3% of massive interacting galaxies (M_{*} > 2*10^{10} M_{solar}) are found to be ULIRGs, compared to 2.6% +/- 0.7% in the control sample. The large spread of IR luminosity to stellar mass ratio among interacting galaxies suggests that this enhancement may depend on the merger stage as well as other as yet unidentified factors (e.g., galaxy structure, mass ratio, orbital characteristics, presence of AGN or bar). The contribution of interacting systems to the total IR luminosity density is moderate (<= 36 %).Comment: 12 pages, 2 figures, 1 table, minor changes to match the proof version, accepted for publication in the ApJL AEGIS Special Issu

Bias and Conditional Mass Function of Dark Halos Based on the Nonspherical Collapse Model

Nonspherical collapse is modelled, under the Zeldovich approximation, by six-dimensional random walks of the initial deformation tensor field. The collapse boundary adopted here is a slightly-modified version of that proposed by Chiueh and Lee (2001). Not only the mass function agrees with the fitting formula of Sheth and Tormen (1999), but the bias function and conditional mass function constructed by this model are also found to agree reasonably well with the simulation results of Jing (1998) and Somerville et al. (2000), respectively. In particular, by introducing a small mass gap, we find a fitting formula for the conditional mass function, which works well even at small time intervals between parent and progenitor halos during the merging history.Comment: 28 pages, 11 figures, section 3.2 complemented, Fig.1 and Fig. 4 modified, version accepted for publication in Ap

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

The Redshift Evolution of Wet, Dry, and Mixed Galaxy Mergers from Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey

We study the redshift evolution of galaxy pair fractions and merger rates for different types of galaxies using kinematic pairs selected from the DEEP2 Redshift Survey. By parameterizing the evolution of the pair fraction as (1+z)^{m}, we find that the companion rate increases mildly with redshift with m = 0.41+-0.20 for all galaxies with -21 < M_B^{e} < -19. Blue galaxies show slightly faster evolution in the blue companion rate with m = 1.27+-0.35 while red galaxies have had fewer red companions in the past as evidenced by the negative slope m = -0.92+-0.59. We find that at low redshift the pair fraction within the red sequence exceeds that of the blue cloud, indicating a higher merger probability among red galaxies compared to that among the blue galaxies. With further assumptions on the merger timescale and the fraction of pairs that will merge, the galaxy major merger rates for 0.1 < z <1.2 are estimated to be ~10^{-3}h^{3}Mpc^{-3}Gyr^{-1} with a factor of 2 uncertainty. At z ~ 1.1, 68% of mergers are wet, 8% of mergers are dry, and 24% of mergers are mixed, compared to 31% wet mergers, 25% dry mergers, and 44% mixed mergers at z ~ 0.1. The growth of dry merger rates with decreasing redshift is mainly due to the increase in the co-moving number density of red galaxies over time. About 22% to 54% of present-day L^{*} galaxies have experienced major mergers since z ~ 1.2, depending on the definition of major mergers. Moreover, 24% of the red galaxies at the present epoch have had dry mergers with luminosity ratios between 1:4 and 4:1 since z ~ 1. Our results also suggest that the wet mergers and/or mixed mergers may be partially responsible for producing red galaxies with intermediate masses while a significant portion of massive red galaxies is assembled through dry mergers at later times.Comment: 11 pages, 8 figures, ApJ Accepted, minor changes to match the journal proof versio

Density waves in the shearing sheet V. Feedback cycle for swing amplification by non-linear effects

Non-linear effects in the dynamical evolution of a shearing sheet made of stars are studied. First the implications of hitherto neglected non-linearities of the Boltzmann equation for the dynamical evolution of the shearing sheet are investigated. Using a formalism developed previously on the basis of the linearized Boltzmann equation it is demonstrated that the inclusion of the non-linear term leads to a feedback cycle for swing amplified density waves in the unbounded shearing sheet. Such a feedback is unique to star disks and is not known for gas disks. In order to present concrete examples of the non-linear feedback cycle a SCF code was developed and numerical simulations of the dynamical evolution of the shearing sheet are performed. The numerical results seem to confirm the theoretical predictions. The evolution of the shearing sheet resembles closely and might actually explain the recurrent spiral instabilities found in large-scale numerical simulations of the dynamical evolution of galactic disks.Comment: 13 pages, 11 figures, accepted by Astron. Astrophy