315 research outputs found
The Structure of Clusters with Bimodal Distributions of Galaxy Radial Velocities. I. A1035
The structure of the A1035 cluster of galaxies (10h32m +40d13', cz ~ 22000
km/s), which exhibits a bimodal distribution of galaxy radial velocities
(\Delta V\approx 3000 km/s), is analyzed using three methods of determining the
relative distances to clusters from early-type galaxies: the Kormendy relation
corrected for the dependence of residuals on galaxy magnitude, the photometric
plane, and the fundamental plane. We use the data obtained with the 1-m
telescope of the Special Astrophysical Observatory of the Russian Academy of
Sciences and SDSS (DR5) data to show that A1035 consists of two gravitationally
unbound independent clusters. These clusters with the velocity dispersions of
566 km/s and 610 km/s and masses within R_200 equal to 2.7 10^14 and 3.5 10^14
M_sun, respectively, obey the Hubble law.Comment: 13 pages, 3 tables, 6 figure
In situ analysis of garnet inclusion in diamond using single-crystal X-ray diffraction and X-ray micro-tomography
none9A single crystal of garnet enclosed in a diamond from the Jericho kimberlite (Slave Craton, Canada) has been investigated using X-ray diffraction and X-ray micro-tomography. The novel experimental approach allowed us to determine the crystal structure of the garnet. The unit-cell edge a and fractional atomic coordinates of oxygen were used to determine the composition via an updated Margules model for garnets. The composition is Pyr(0.41(5))Alm(0.36(7))Gro(0.22(1))Uva(0.01(1)), which is indistinguishable from the eclogitic garnets found in other Jericho diamonds. We also demonstrated that residual pressures on the inclusion of up to 1 GPa do not affect significantly the determination of the garnet composition by structure refinement.noneFABRIZIO NESTOLA;M. MERLI;PAOLO NIMIS;M. PARISATTO;M. KOPYLOVA;A. DE;M. LONGO;L. ZIBERNA;M. MANGHNANINestola, Fabrizio; M., Merli; Nimis, Paolo; Parisatto, Matteo; M., Kopylova; A., De; Longo, Micaela; Ziberna, Luca; M., Manghnan
Detailed Study of the Ursa Major Supercluster of Galaxies Using the 2MASS and SDSS Catalogs
We study the infrared (K_s band) properties of clusters of galaxies in the
Ursa Major supercluster using data from 2MASS (Two-Micron All-Sky Survey) and
SDSS (Sloan Digital Sky Survey). We identified three large filaments with mean
redshifts of z = 0.051, 0.060, and 0.071. All clusters of the supercluster are
located in these filaments. We determined the total K_s-band luminosities and
masses for 11 clusters of galaxies within comparable physical regions (within a
radius R_200 close to the virial radius) using a homogeneous method. We
constructed a combined luminosity function for the supercluster in this region,
which can be described by the Schechter function with the following parameters:
M*_K = -24^m.50 and \alpha = -0.98. The infrared luminosities of the clusters
of galaxies correlate with their masses; the M/L_K ratios of the systems
increase with their masses (luminosities), with most of the Ursa Major clusters
of galaxies (particularly the richer ones) closely following the relations
derived previously for a large sample of clusters and groups of galaxies. The
total mass-to-infrared-luminosity ratio is 52 M_{\odot}/L_{\odot} for six Abell
clusters and 49 M_{\odot}/L_{\odot} for all of the clusters, except Anon2.Comment: 16 pages, 5 figure
Solid-state active media of tunable organic-compound lasers pumped with a laser. I. An XeCl laser
Оцифровано в НБ ТГ
Multimodality of rich clusters from the SDSS DR8 within the supercluster-void network
We study the relations between the multimodality of galaxy clusters drawn
from the SDSS DR8 and the environment where they reside. As cluster environment
we consider the global luminosity density field, supercluster membership, and
supercluster morphology. We use 3D normal mixture modelling, the
Dressler-Shectman test, and the peculiar velocity of cluster main galaxies as
signatures of multimodality of clusters. We calculate the luminosity density
field to study the environmental densities around clusters, and to find
superclusters where clusters reside. We determine the morphology of
superclusters with the Minkowski functionals and compare the properties of
clusters in superclusters of different morphology. We apply principal component
analysis to study the relations between the multimodality parametres of
clusters and their environment simultaneously. We find that multimodal clusters
reside in higher density environment than unimodal clusters. Clusters in
superclusters have higher probability to have substructure than isolated
clusters. The superclusters can be divided into two main morphological types,
spiders and filaments. Clusters in superclusters of spider morphology have
higher probabilities to have substructure and larger peculiar velocities of
their main galaxies than clusters in superclusters of filament morphology. The
most luminous clusters are located in the high-density cores of rich
superclusters. Five of seven most luminous clusters, and five of seven most
multimodal clusters reside in spider-type superclusters; four of seven most
unimodal clusters reside in filament-type superclusters. Our study shows the
importance of the role of superclusters as high density environment which
affects the properties of galaxy systems in them.Comment: 16 pages, 12 figures, 2 online tables, accepted for publication in
Astronomy and Astrophysic
ОЦЕНКА ЦЕЛЕСООБРАЗНОСТИ ФОРМИРОВАНИЯ ЛОГИСТИЧЕСКИХ СИСТЕМ ОБСЛУЖИВАНИЯ ПАССАЖИРОВ
Recent studies show that there is still no clear universal system to assess feasibility of forming a logistics chain of passenger service, which would take into account not only the interests of each individual mode of transport or passenger traffic segment, but would consider the whole transport system of load area (country, region, metropolis, etc.). Approaches to solving this problem are demonstrated by the authors, using analytical methods and logistics characteristics of transport, its consumer properties, reflecting value of a transport product for a passenger and technical and technological capabilities of each carrier.Исследования последних лет показывают, что до сих пор отсутствует четкая универсальная система оценки целесообразности формирования логистической цепочки обслуживания пассажиров, которая учитывала бы не только интересы каждого отдельного вида транспорта или сегмента пассажиропотока, но и рассматривала бы в целом транспортную систему района тяготения (страны, региона, мегаполиса и т. д.). Свои подходы к решению этой задачи демонстрируют авторы статьи, используя аналитические методы и логистические характеристики транспорта, потребительские его качества, отражающие ценность транспортного продукта для пассажира и технико-технологические возможности каждого перевозчика
Precise phylogenetic analysis of microbial isolates and genomes from metagenomes using PhyloPhlAn 3.0
Microbial genomes are available at an ever-increasing pace, as cultivation and sequencing become cheaper and obtaining metagenome-assembled genomes (MAGs) becomes more effective. Phylogenetic placement methods to contextualize hundreds of thousands of genomes must thus be efficiently scalable and sensitive from closely related strains to divergent phyla. We present PhyloPhlAn 3.0, an accurate, rapid, and easy-to-use method for large-scale microbial genome characterization and phylogenetic analysis at multiple levels of resolution. PhyloPhlAn 3.0 can assign genomes from isolate sequencing or MAGs to species-level genome bins built from >230,000 publically available sequences. For individual clades of interest, it reconstructs strain-level phylogenies from among the closest species using clade-specific maximally informative markers. At the other extreme of resolution, it scales to large phylogenies comprising >17,000 microbial species. Examples including Staphylococcus aureus isolates, gut metagenomes, and meta-analyses demonstrate the ability of PhyloPhlAn 3.0 to support genomic and metagenomic analyses
Tunka-Rex Virtual Observatory
Tunka-Rex (Tunka Radio Extension) was a detector for ultra-high energy cosmic rays measuring radio emission for air showers in the frequency band of 30-80 MHz, operating in 2010s. It provided an experimental proof that sparse radio arrays can be a cost-effective technique to measure the depth of shower maximum with resolutions competitive to optical detectors. After the decommissioning of Tunka-Rex, as last phase of its lifecycle and following the FAIR (Findability — Accessibility — Interoperability — Reuse) principles, we publish the data and software under free licenses in the frame of the TRVO (Tunka-Rex Virtual Observatory), which is hosted at KIT under the partnership with the KCDC and GRADLCI projects. We present the main features of TRVO, its interface and give an overview of projects, which benefit from its open software and data
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