The investigation of Moskalenko's 1959 optical transient field inside GRB791101 error box

We report the results of an optical study of Moskalenko's OT 1959 field. The deep CCD images were obtained at the 6-m telescope of SAO RAS on June 8/9 1994. The BVR photometry of objects near the position of Moskalenko's OT 1959 are presented. An object with V= 23.43 and peculiar colours B-V= 0.9 and V-R= 1.10 was found. It is a possible candidate for the 1959 optical flash.     

Peculiar motions of galaxy clusters in the regions of the Corona Borealis,Bootes, Z 5029/A 1424, A 1190, A 1750/A 1809 superclusters of galaxies

We present results of the study of peculiar motions of 57 clusters and groups of galaxies in the regions of the Corona Borealis (CrB), Bootes (Boo), Z5029/A1424, A1190, A1750/A1809 superclusters of galaxies and the galaxy clusters located beyond massive structures (0.05 < z < 0.10). Using the SDSS (Data Release 8) data, a sample of early-type galaxies was compiled in the systems under study, their fundamental planes were built, and relative distances and peculiar velocities were determined. Within the galaxy superclusters, significant peculiar motions along the line of sight are observed with rms deviations of 652 ± 50 kms^?1—in CrB, 757 ± 70 kms^?1—in Boo. In the most massive A2065 cluster in the CrB supercluster, no peculiar velocity was found. Peculiar motions of the other galaxy clusters can be caused by their gravitational interaction both with A2065 and with the A2142 supercluster. It has been found that there are two superclusters projected onto each other in the region of the Bootes supercluster with a radial velocity difference of about 4000 kms^?1. In the Z 5029/A1424 supercluster near the rich Z5029 cluster, the most considerable peculiar motions with a rms deviations of 1366 ± 170 kms^?1 are observed. The rms deviations of peculiar velocities of 20 clusters that do not belong to large-scale structures is equal to 0 ± 20 kms^?1. The whole sample of the clusters under study has the mean peculiar velocity equal to 83 ± 130 kms^?1 relative to the cosmic microwave background.     

Spectroscopy of “Big Trio” objects using the “Scorpio” spectrograph of the 6-m telescope of the Special Astrophysical Observatory

We present the results of spectroscopy of 71 objects with steep and ultra-steep spectra (α < −0.9, S ∝ ν ^α) from the “Big Trio” (RATAN-600-VLA-BTA) project, performed with the “Scorpio” spectrograph on the 6-m telescope of the Special Astrophysical Observatory (Russian Academy of Sciences). Redshifts were determined for these objects. We also present several other parameters of the sources, such as their R magnitudes, maximum radio sizes in seconds of arc, flux densities at 500, 1425, and 3940 MHz, radio luminosities at 500 and 3940 MHz, and morphology. Of the total number of radio galaxies studied, four have redshifts 1 ≤ z < 2, three have 2 ≤ z < 3, one has 3 ≤ z < 4, and one has z = 4.51. Thirteen sources have redshifts 0.7 < z < 1 and 15 have 0.2 < z < 0.7.Of all the quasars studied, five have redshifts 0.7 < z < 1, seven have 1 ≤ z < 2, four have 2 ≤ z < 3, and one has z = 3.57. We did not detect any spectral lines for 17 objects.     

Distribution and Activity of Bacteriobenthos in the Upper Volga Reservoirs

Regularities of bacteria distribution in the bottom sediments of the Upper Volga reservoirs are studied. Human-induced changes in the structure and activity of bacteriobenthos communities occurring in water body areas adjacent to towns and settlements are described. Reservoir zones subject to long-term human impact are distinguished.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 489–499.Original Russian Text Copyright © 2005 by Kosolapov, Krylova, Kopylov.     

The Ursa Major supercluster of galaxies: I. The luminosity function

Catalogs of bright galaxies in the central regions of 11 clusters in the Ursa Major supercluster are presented. Absolute and relative coordinates and total B and R magnitudes are given for each galaxy. Plates taken with the 2-m Tautenburg Observatory telescope and CCD images obtained with the 6-m and 1-m SAO telescopes are used. The luminosity functions (LFs) for galaxies in the cluster nuclei (3 Mpc×3 Mpc) and the composite LF for the supercluster are constructed. The composite LF is well fitted by a Schechter function with $M_B^ * = - 20\mathop .\limits^m 91$ , α=?1.02 and with $M_R^ * = - 22\mathop .\limits^m 39$ , α=?1.06. A comparison with the LFs of field galaxies and of various samples of clusters and superclusters shows that the Ursa Major supercluster have LF parameters characteristic of the field and, thus, differ from those of the Corona Borealis supercluster, which is apparently at a later stage of dynamical evolution.     

Structure of clusters with bimodal distribution of radial velocities of galaxies. IV: A1569

We report the results of study of the A1569 cluster (12 ^h 36^m.3, +16°35′) and the neighboring A1589 cluster (12 ^h 41^m.3, +18°34′), making up a pair (a supercluster) with a projected size of about 10Mpc. This study is done within the framework of our program for investigating the galaxy clusters with bimodal velocity distributions (i.e., clusters where the velocities of subsystems differ by more than Δcz ∼ 3000 km/s). In the A1569 cluster we have identified two subsystems: A1569A (cz = 20613 km/s) and A1569B (cz = 23783 km/s). These subsystems have the line-of-sight velocity dispersions of 484 km/s and 493 km/s, and dynamic masses within the R ₂₀₀ radius equal to 1.8 × 10¹⁴ and 2.0 × 10¹⁴ M _⊙, respectively. We directly estimate the distances to these subsystems using three methods applied to earlytype galaxies: the Kormendy relation, photometric plane, and fundamental plane. To this end, we use the results of our observations made with the 1-m telescope of the SAO RAS and the data adopted from the SDSS DR7 catalog. We found that A1569 consists of two independent clusters. The A1569B cluster is located at the Hubble distance corresponding to its radial velocity. The A1569A cluster has a peculiar velocity of −1290 ± 630 km/s, which can be explained by the effect of the more massive A1589 cluster (with a mass of 7.9 × 10¹⁴ M _⊙) and of the supercluster where it resides. In all the four bimodal clusters that we studied within the framework of our program, A1035, A1775, A1831, and A1569, the subsystems are independent clusters lying close to the Hubble relation between redshift and distance.     

Investigation of properties of galaxy clusters in the Hercules supercluster region

We investigated the properties of galaxy clusters in the region of the Hercules supercluster using observational data from the SDSS and 2MASS catalogs and the NED. We have selected 13 galaxy clusters with a total dynamical mass of 4.82 × 10¹⁵ M _⊙ in a 100 × 45 Mpc supercluster region in the plane of the sky (0.030 < z < 0.041). In addition, our sample includes eight clusters from the immediate neighborhoods of the superclusters and ten field clusters at the same z. The derived properties of the rich Hercules supercluster are shown in comparison with the data for the poor Leo supercluster. The main parameters of the virialized galaxy cluster regions in the near infrared (K _s ) for the Hercules supercluster differ from those for the Leo supercluster: the number of galaxies and the total luminosity (to a limiting magnitude of ?21 _· ^m 5) increase with cluster mass (L _K,200 ∝ M ₂₀₀ ^0.91±0.07 and N ₂₀₀ ∝ M ₂₀₀ ^0.94±0.07 ), but the dependences are steeper by 0.28 and 0.22. In the virialized cluster regions, the fraction of early-type galaxies selected by the bulge contribution, concentration index, and u t= r color is, on average, 66% (60% in Leo, 70% in the field) among the galaxies brighter than ?23 _· ^m 3 and 54% (51% in Leo, 61% in the field) among the galaxies brighter than ?22 _· ^m 3. The fraction of early-type galaxies in the superclusters does not change with galaxy cluster mass and luminosity. The composite luminosity function of the rich Hercules supercluster is described by a Schechter function and does not differ from the luminosity function of the poor Leo supercluster for the luminosity interval [?26 ^m , ?21 _· ^m 5] but differs from the field luminosity function at the same z determined from ten galaxy clusters.     

Bacteria and Viruses in Arctic Sea Ice

Oceanology - We studied vertical distribution of bacteria and viruses in different layers of the Arctic sea ice drilled at the North Pole. The sampled multi-year ice was characterized by uneven...     

Analysis of a sample of RC catalog objects in the region overlapping with the areas covered by FIRST and SDSS surveys. II: Optical identification with the SDSS survey and USNO-B1 and 2MASS catalogs

We report the results of optical identification of a sample of RC catalog radio sources with the FIRST and SDSS surveys. For 320 sources identified with NVSS and FIRST objects we perform optical identification with the SDSS survey. When selecting optical candidates we make maximum use of the information about the structure of radio sources as provided by the FIRST survey images. We find optical candidates for about 70% of all radio sources.     

Analysis of the properties of clusters of galaxies in the region of the Ursa Major supercluster

We analyze the properties of the clusters of galaxies in the region of the Ursa Major (UMa) supercluster using observational data from SDSS and 2MASS catalogs. The region studied includes a supercluster (with a galaxy and cluster overdensity of 3 and 15, respectively) and field clusters inside the 150-Mpc diameter surrounding region. The total dynamical mass of 10 clusters of galaxies in UMa is equal to 2.25 × 10¹⁵ M _⊙, and the mass of 11 clusters of galaxies in the UMa neighborhood is equal to 1.70 × 10¹⁵ M _⊙. The fraction of early-type galaxies brighter than M _K ^* + 1 in the virialized regions of clusters is, on the average, equal to 70%, and it is virtually independent on the mass of the cluster. The fraction of these galaxies and their average photometric parameters are almost the same both for UMa clusters and for the clusters located in its surroundings. Parameters of the clusters of galaxies, such as infrared luminosities up to a fixed magnitude, the mass-to-luminosity ratio, and the number of galaxies have almost the same correlations with the cluster mass as in other samples of galaxies clusters. However, the scatter of these parameters for UMa member clusters is twice smaller than the corresponding scatter for field clusters, possibly, due to the common origin of UMa clusters and synchronized dynamical evolution of clusters in the supercluster.