Репозитарій ОНУ імені І.І.Мечникова

Перегляд за Автор "Panko, Olena O."

Зараз показуємо 1 - 20 з 28

A catalogue of galaxy clusters and groups as base for new galaxy supercluster catalogue
(Odessa I.I. Mechnikov National University, 2009) Panko, Olena O.; Панько, Олена Олексіївна; Панько, Елена Алексеевна
Alignment of galaxies in subclustres placed in rich regions
(2019) Korshunov, V.; Panko, Olena O.; Панько, Елена Алексеевна; Панько, Олена Олексіївна
The study of galaxies orientation is one of standard tests of galaxies formation scenarios. In filaments and walls the elliptical and disc galaxies chow different orientations (Joachimi et al., 2015).
Detailed morphology of the rich concentrated Galaxy Clusters
(Одеський національний університет імені І. І. Мечникова, 2018) Panko, Olena O.; Sirginava, A.; Stepaniuk, A.; Панько, Елена Алексеевна; Сиргинава, А.; Степанюк, А.; Панько, Олена Олексіївна
The results of the detailed analysis of the 2D distribution of galaxies in 28 rich galaxy clusters with significant concentration to the cluster center are present. The analysis was executed in these directions: the detection of regular substructures and peculiarities in the galaxy distribution. The role of brightest cluster members was taken into account too. The input data were selected from “The Catalogue of Galaxy Clusters and Groups” and list of galaxies of Muenster Red Sky Survey. Concentrated galaxy clusters are evolved, virialized structures. Substructures in this type of clusters must be feeble marked. Nevertheless we detected significant part of concentrated galaxy clusters having different kinds of peculiarities, namely crossing and divaricating filaments or X and Y-type peculiarities, as well as curved strips and short dense chains. 2 clusters having extremely density of galaxies were attributed as superconcentrated/compact type.
Galaxy Cluster Mergers: the use of the computer modeling
(Одеський національний університет імені І. І. Мечникова, 2023) Berkovskyi, M.; Panko, Olena O.; Miroshnik, N.; Панько, Олена Олексіївна
We show the possibilities of the methods of computer modeling of the galaxy cluster merger process with diﬀerent initial parameters for the investigation of the features of the clusters after colliding. Weconsideredthegalaxyclustersasevolvingobjects including through collisions. Computer modeling of galaxy cluster mergers and comparing its results with observational data makes it possible to determine the evolutionary status of real clusters with complex internal structures. Within the study, we analyzed in detail a series of models of the galaxy clusters’ merger consequences by ZuHone under diﬀerent initial conditions like mass ratio, initial collision parameter, or plasma coeﬃcient β. The considered time intervals were from 0 to 4.8 billion years, from 0 to 6 billion years, and from 0 to 10 billion years, depending on the initial conditions. Basedontheimagesofthesimulatedgalaxyclusters, maps of the distribution of the total mass density and X-ray radiation were created and compared with observations. We showed a good perspective to use this catalog for studying galaxy clusters having compound inner structure.
The inner structure of galaxy clusters in the triplets
(Odesa I. I. Mechnikov National University, 2024) Panko, Olena O.; Yemelianov, Sviatoslav I.; Панько, Олена Олексіївна; Ємельянов, Святослав Ігорович
The inner structure of galaxy clusters is determined by the interaction of baryon matter with the surrounding structures and the influence of the underlying dark matter. For the search of the results of such interaction, we select the 18 triplets (11 elongated and 7 rounded ones) of galaxy clusters from the triplets founded in the PF Catalogue of Galaxy Clusters and Groups (Panko & Flin). The shape of the all founded triplets vary from practically regular triangle to straight chain, i.e., the ellipticity of the best-fitted ellipse of the triplets ranged from 0.12 to 0.92. We select the triplets with ellipticities in the range 0.8−1.0 as the first subset and with the ellipticities in the range 0.1−0.4 as the second one. The comparison the results obtained for two subsets allowed to conclude the elongated triplets arise along the filament. Binggeli effect was detected in a major part of clusters. In the linear substructure L11 in PF 0369–7499 galaxies show also perpendicular alignment in contrast to other galaxies of this cluster. We suppose the substructures in the galaxy clusters of our data set must be connected with the influence of other triplet members.
Investigation of the orientation of galaxies in clusters: the importance, methods and results of research
(2019) Pajowska, Paulina; Godlowski, Wlodzimierz; Zhu, Zong-Hong; Popiela, Joanna; Panko, Olena O.; Flin, Piotr; Панько, Олена Олексіївна; Панько, Елена Алексеевна
Various models of structure formation can account for various aspects of the galaxy formation process on different scales, as well as for various observational features of structures. Thus, the investigation of galaxies orientation constitute a standard test of galaxies formation scenarios since observed variations in angular momentum represent fundamental constraints for any model of galaxy formation. We have improved the method of analysis of the alignment of galaxies in clusters. Now, the method allows to analyze both position angles of galaxy major axes and two angles describing the spatial orientation of galaxies. The distributions of analyzed angles were tested for isotropy by applying different statistical tests. For sample of analyzed clusters we have computed the mean values of analyzed statistics, checking whether they are the same as expected ones in the case of random distribution of analyzed angles. The detailed discussion of this method has been performed. We have shown how to proceed in many particular cases in order to improve the statistical reasoning when analyzing the distribution of the angles in the observational data. Separately, we have compared these new results with those obtained from numerical simulations. We show how powerful is our method on the example of galaxy orientation analysis in 247 Abell rich galaxy clusters. We have found that the orientations of galaxies in analyzed clusters are not random. It means that we genuinely confirmed an existence of the alignment of galaxies in rich Abells’ galaxy clusters. This result is independent from the clusters of Bautz-Morgan types.
Isolated clusters of PF catalogue
(Astroprint, 2012) Panko, Olena O.; Andrievsky, Serhii M.; Андрієвський, Сергій Михайлович; Андриевский, Сергей Михайлович; Панько, Елена Алексеевна; Панько, Олена Олексіївна
The properties of isolated galaxy clusters are discussed. The clusters were found among 1746 PF clusters inclusive 50 and more galaxies in structure field. For 19 clusters with distances to the nearest neighbour larger than 68.5 h-1 Mpc we assigned the morphological types of these clusters according to Abell and Bauts & Morgan. The existence of preferential planes and angular momenta of isolated clusters was assumed. We connect evolution of isolated clusters with common large-scale characteristics.
Linear substructures in Galaxy clusters
(Odesa I. I. Mechnikov National University, 2019) Panko, Olena O.; Korshunov, V.; Yemelianov, Stanislav I.; Zabolotnii, V.; Панько, Олена Олексіївна; Ємельянов, Станіслав Ігорович
We propose detailed scheme that is describing the morphology of linear substructures in galaxy clusters. Our base morphological scheme divides galaxy clusters using numerical criteria according the parameters: concentration to the cluster center, the presence of linear substructure, orientation of images of galaxies, the role of brightest cluster members, the shape of galaxies. Our analysis of 2D distribution of galaxies based on study more than 500 galaxy clusters. We show the linear substructures are regular peculiarity in galaxy clusters. Our approach allows to divide filamentary and edge-on wall substructures and to select galaxy clusters with possible peculiarities in hot gas and/or DM distribution.
Morphological types of 254 Rich PF Galaxy Clusters
(Astroprint, 2014) Panko, Olena O.; Andrievskii, Alexander M.; Gotsulyak, A. V.; Андрієвський, Олександр Михайлович; Панько, Елена Алексеевна; Панько, Олена Олексіївна; Андриевский, Александр Михайлович
We determined the morphological types for 254 rich galaxy clusters from the PF Catalogue of Galaxy Clusters and Groups. The data get contains the PF galaxy clusters, which have no ACO coinciding ones. The applied morphological scheme was combined of the prevalent classifications, such as Bautz-Morgan, Rood-Sastry etc approaches. We assigned the morphological types using numerical criteria and taking into consideration concentration to the cluster center, the signs of preferential direction or plane in the cluster, and the positions of the brightest galaxies. The features of the data set are discussed.
Morphology subtypes in rich galaxy cluster with intermediate concentration
(2019) Zabolotnii, Viktor; Panko, Olena O.; Панько, Елена Алексеевна; Панько, Олена Олексіївна; Korshunov, Valerii; Yemelianov, Yaroslav
The Universe consists of many galaxy clusters which we observe on the sky. Galaxy cluster is structure that consists of many galaxies (from 10 to 1000). In our work we are looking for rich clusters (100 and more galaxies) with intermediate concentration. We used Panko classification of galaxy clusters.
On the existence of young embedded clusters at high Galactic latitude
(2017) Turner, D. G.; Carraro, G.; Panko, Olena O.; Панько, Олена Олексіївна; Панько, Елена Алексеевна
Careful analyses of photometric and star count data available for the nine putative young clusters identified by Camargo et al. (2015, 2016) at high Galactic latitudes reveal that none of the groups contain early-type stars, and most are not significant density enhancements above field level. 2MASS colours for stars in the groups match those of unreddened late-type dwarfs and giants, as expected for contamination by (mostly) thin disk objects. A simulation of one such field using only typical high latitude foreground stars yields a colour-magnitude diagram that is very similar to those constructed by Camargo et al. (2015, 2016) as evidence for their young groups as well as the means of deriving their reddenings and distances. Although some of the fields are coincident with clusters of galaxies, one must conclude that there is no evidence that the putative clusters are extremely young stellar groups.
Orientation of Brighter Galaxies in Nearby Galaxy Clusters
(2009) Panko, Olena O.; Juszczyk, T.; Flin, P.; Панько, Олена Олексіївна; Панько, Елена Алексеевна
A sample of 6188 nearby galaxy structures, complete to rF = 18. m 3 and containing at least 10 members each, was the observational basis for an investigation of the alignment of bright galaxies with the major axes for the parent clusters. The distribution of position angles for galaxies within the clusters, specifically the brightest, the second brightest, the third, and the tenth brightest galaxies was tested for isotropy. Galaxy position angles appear to be distributed isotropically, as are the distributions of underlying cluster structure position angles. The characterization of galaxy structures according to richness class also appears to be isotropic. Characterization according to BM types, which are known for 1056 clusters, is more interesting. Only in the case of clusters of BM type I is there an alignment of the brightest cluster member with the major axis of the parent cluster. The effect is observed at the 2 significance level. In other investigated cases the distributions are isotropic. The results confirm the special role of cD galaxies in the origin/evolution of large-scale structures.
The possibilities of the “Cluster Cartography” tool for the study of the inner structures of galaxy clusters
(Odesa I. I. Mechnikov National University, 2021) Yemelianov, Sviatoslav I.; Panko, Olena O.; Ємельянов, Станіслав Ігорович; Панько, Олена Олексіївна
We describe the possibilities of the “Cluster Cartography” tool which was created for detailed study of the 2D distribution of galaxies in the clusters. The main tasks of the “Cluster Cartography” tool were the detailed study of the morphology of galaxy clusters using the statistically significant numerical criteria as well as to detect their regular peculiarities. The tool allows to create the 2D map with positions of galaxies in the cluster field and show for each cluster member its shape and orientation as a best-fit ellipse using input catalogue data. The size of symbols for galaxies correspond to input data. It may reflect the galaxy image in arcseconds from catalogue in the map 4000 × 4000 arcsec. Another way connects the size of the symbol with the magnitude of the galaxy. Tool is able to build the map in four modes: the symbols are dots; the symbols are circles with diameters reflected the magnitudes of galaxies; the symbols are ellipses with size reflected the magnitudes and both ellipticities and orientation from the input catalogue; the symbols illustrate the shape of galaxies in projection to the celestial sphere. The “Cluster Cartography” algorithms allow to detect the standard cases in galaxy distribution, such as the degree of concentration to the cluster center and/or to some line on a statistically significant level using the numerical criteria. Also “Cluster Cartography” allows to detect other features, such as crosses, semi-crosses, complex crosses and short compact chains, as well as to export the list of galaxies forming the peculiarities for the future study. The final version of the “Cluster Cartography” allows to realize the modern scheme for detailed morphological classification of galaxy clusters. The “Cluster Cartography” is powerful and perspective tool for study of features of galaxy clusters.
The Adopted Morphological Types of 247 Rich PF Galaxy Clusters
(2016) Panko, Olena O.; Bajan, Katarzyna; Flin, Piotr; Gotsulyak, Alla; Панько, Олена Олексіївна; Панько, Елена Алексеевна
Morphological types were determined for 247 rich galaxy clusters from the PF Catalogue of Galaxy Clusters and Groups. The adopted types are based on classical morphological schemes and consider concentration to the cluster center, the signs of preferential direction or plane in the cluster, and the positions of the brightest galaxies. It is shown that both concentration and preferential plane are significant and independent morphological criteria.
THE CRITERIA FOR MORPHOLOGICAL CLASSIFICATION OF PF GALAXY CLUSTERS
(Astroprint, 2013) Panko, Olena O.; Панько, Елена Алексеевна; Панько, Олена Олексіївна
The morphological types of galaxy clusters resulting from their outward appearance is physically related to the clusters and their member galaxies. Presented here is an adopted system of morphological types of galaxy clusters based on the Zwicky, Boutz & Morgan, Rood & Sastry, and L´opez-Cruz systems. The adopted types are suitable for automated classification of galaxy clusters from The Catalogue of Galaxy Clusters and Groups (Panko & Flin 2006). Numerical criteria describing 6 main types were distinguished: Concentrated C, Intermediate I, Open O, Line L, Flat F, and cD. The types correspond to the base divisions from regular to irregular clusters, but also note the presence of preferential direction or plane in each cluster.
The Evolution of Low-Redshift Galaxy Structures
(2009) Biernacka, Monika; Flin, Piotr; Panko, Olena O.; Панько, Олена Олексіївна; Панько, Елена Алексеевна
Ellipticities for 6188 low-redshift (z < 0.18) poor and rich galaxy structures have been examined along with their evolution using an optical observational base that is statistically complete. The shape of each structure projected on the celestial sphere was determined using the covariance ellipse method. Analysis of the data indicates that structure ellipticity changes with redshift, being smaller for nearby objects and greater for those located further away. Such a change is also described better by quadratic or exponential relations than by a simple linear scheme. It is concluded that between redshifts of z = 0.18 and z = 0 we observe the dynamical evolution of galaxy clusters. Such a change in ellipticity with redshift is expected in ΛCDM models.
The Investigation of the Luminosity Function for Sample 6168 Galaxy Clusters
(2018) Godlowski, Wlodzimierz; Popiela, Joanna; Biernacka, Monika; Bajan, Katarzyna; Panko, Olena O.; Pajowska, Paulina; Flin, Piotr; Панько, Олена Олексіївна; Панько, Елена Алексеевна
The issue of construction of the luminosity function is an important problem for analysis of large scale structure statistics and interpretation of astronomical object counts In the present paper we discuss the the issure of the construction of the luminosity function for galaxy clusters. The problem is solved based on counting brightness of galaxies belonging to 6168 galaxy clusters selected from Panko & Flin (2006) Catalogue. We show that the galaxy clusters are characterized by the luminosity function signi cantly di erent than that obtained for both: individual optical galaxies and radiogalaxies. We discuss the signi cance of this result for the theories of the structure formation.
The Orientation of Galaxies in Galaxy Clusters
(2010) Godlowski, Wlodzimierz; Pajowska, Paulina; Panko, Olena O.; Flin, Piotr; Панько, Олена Олексіївна; Панько, Елена Алексеевна
We present an analysis of the spatial orientations of galaxies in 247 optically selected rich Abell clusters which have at least 100 members in the considered area.We investigated the relation between angles that give information about galaxy angular momenta and the number of members in each structure. The position angles of the galaxies’ major axes, as well as two angles describing the spatial orientation of the galaxy plane, were tested for isotropy by applying three different statistical tests. It is found that the values of the statistics increase with the amount of the galaxies’ members, which is equivalent to the existence of a relation between anisotropy and the number of galaxies in a cluster. The search for connection between the galaxies’ alignments and Bautz–Morgan (BM) morphological types of examined clusters showed a weak dependence. A statistically marginal relation between velocity dispersion and cluster richness was observed. In addition, it was found that the velocity dispersion decreases with BM type at almost 3σ level. These results show the dependence of alignments with respect to clusters’ richness, which can be regarded as an environmental effect.
The peculiarities in O-type Galaxy clusters
(Одеський національний університет імені І. І. Мечникова, 2017) Panko, Olena O.; Emelyanov, S. I.; Панько, Елена Алексеевна; Панько, Олена Олексіївна
We present the results of analysis of 2D distribution of galaxies in galaxy cluster fields. The Catalogue of Galaxy Clusters and Groups PF (Panko & Flin) was used as input observational data set. We selected open rich PF galaxy clusters, containing 100 and more galaxies for our study. According to Panko classification scheme open galaxy clusters (O-type) have no concentration to the cluster center. The data set contains both pure O-type clusters and O-type clusters with overdence belts, namely OL and OF types. According to Rood & Sastry and Struble & Rood ideas, the open galaxy clusters are the beginning stage of cluster evolution. We found in the O-type clusters some types of statistically significant regular peculiarities, such as two crossed belts or curved strip. We suppose founded features connected with galaxy clusters evolution and the distribution of DM inside the clusters.
The Properties of Nearby Galaxy Structures
(2009) Biernacka, Monika; Flin, Piotr; Juszczyk, T.; Panko, Olena O.; Панько, Олена Олексіївна; Панько, Елена Алексеевна
We constructed the statistically uniform catalogue of 6188 galaxy structures, having at least 10 members in the structure field. These structures were extracted through the application of the Voronoi tessellation to Muenster Red Sky Survey which is a catalogue of galaxies based on scans of 217 ESO plates in the region covering about 5000 square degrees. We found that the shape of structures projected on the celestial sphere is different for rich and poor structures, which can reflect condition during their formation. Recent (for z < 0.18) weak dynamical evolution of galaxy clusters is observed. The distributions of position angles of ten brightest galaxies in structure are isotropic. The position angle of the brightest cluster member tend to be align with the parent cluster major axis only in the case of BM type I clusters, this is clusters containing cD galaxy.

Перегляд за Автор "Panko, Olena O."

Результатів на сторінці

Налаштування сортування