The radio galaxy RC J1148+0455

Based on data from the MIT-GB-VLA 4850-MHz survey, we investigate the radio structure of RC J1148+0455 with a steep radio spectrum (α=?1.04) from the COLD catalog. The radio source consists of two components, each having a complex structure. We analyze an optical identification of the source by using 6-m telescope images. The centroid of the radio source falls on a group of eight galaxies at a 24 ^m level in R.     

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.     

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.     

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.     

Plankton distribution associated with frontal zones in the vicinity of the Pribilof Islands

We studied the effect of four types of fronts, the coastal front, the middle front, the shelf partition front and the shelf break front on the quantitative distribution and the composition of plankton communities in the Pribilof area of the eastern Bering Sea shelf in late spring and summer of 1993 and 1994. The coastal fronts near St. Paul and St. George Islands and the coastal domains encircled by the fronts featured specific taxonomic composition of planktonic algae, high abundance and production of phytoplankton, as well as large numbers of heterotrophic nanoplankton. The coastal fronts also were characterized by high values of total mesozooplankton biomass, high concentrations of Calanus marshallae, as well as relatively high abundances of Parasagitta setosa and Euphausiacea compared to surrounding shelf waters. We hypothesize that wind-induced erosion of a weak thermocline in the inner part of the coastal front as well as transfrontal water exchange in subthermocline layers result in nutrient enrichment of the euphotic layer in the coastal fronts and coastal domains in summer time. This leads to prolonged high primary production and high phytoplankton biomass. In this paper a new type of front—the shelf partition front located 45–55 km to the north-east off St. Paul Island—is described, which is assumed to be formed by the flux of oceanic domain waters onto the shelf. This front features a high abundance of phytoplankton and a high level of primary production compared to the adjacent middle shelf. Near the southwestern periphery of the front a mesozooplankton peak occurred, composed of C. marshallae, with biomass in the subthermocline layer, reaching values typical for the shelf break front and the highest for the area. High abundance of phyto- and zooplankton as well as heterotrophic nanoplankton and elevated primary production were most often observed in the area adjacent to the shelf break front at its oceanic side. The phyto- and mesozooplankton peaks here were formed by oceanic community species. The summer levels of phytoplankton numbers, biomass and primary production in the shelf break frontal area were similar to those reported for the outer and middle shelf during the spring bloom and the coastal domains and coastal fronts in summer. In the environment with a narrow shelf to the south of St. George Island, the mesozooplankton peak was observed at the inner side of the shelf break front as close as 20 km from the island shore and was comprised of a “mixed” community of shelf and oceanic species. The biomass in the peak reached the highest values for the Pribilof area at 2.5 g mean wet weight m⁻³ in the 0–100 m layer. Details of the taxonomic composition and the numbers and production of phytoplankton hint at the similarity of processes that affect the phytoplankton summer community in the coastal domains of the islands, at the coastal fronts, and at the oceanic side of the shelf break front. The middle front was the only one that had no effect on plankton composition or its quantitative characteristics in June and July. Location of a variety of frontal productive areas within 100 km of the Pribilof Islands creates favorable foraging habitat for higher trophic level organisms, including sea birds and marine mammals, populating the islands.     

The search and investigation of faint blue star-like objects in the small GRB error boxes

A central part of the GRB 790613 field is investigated, which contains about 1/3 of the area of 99% confidence of the GRB localization. Up to V 25 no blue optical counterparts were found. This can be interpreted as the absence in the field of single compact objects of the neutron star type as a possible potential source of -burst, up to a distance of 30 pc.     

Recent dynamics and probable origin of the Tulva Upland in the Perm Foreurals

The Tulva Upland is a meridional neotectonic swell that complicates the eastern Russian Plate in its recent manifestation. The intense recent uplift is expressed in the rise and splitting of terraces of the Kama River and anomalously increasing lateral ruggedness of topography. Having a steep western and a gentle eastern limb, the swell is sharply asymmetric in cross section and additionally is complicated by a chain of local NE-trending uplifts. Several morphostructural indications testify to the substantial role of NW-trending strike-slip faulting in the structure of the swell, which was formed under conditions of latitudinal compression and conjugated meridional extension. Such a stress-strain field is confirmed by the study of mesotectonic structural elements in the western steep limb of the swell regarded as a flexure above a suggested reverse fault. Like many other zones of within-plate dislocations in the Russian Plate, the recent Tulva Swell was formed as a result of folding of sedimentary fill and inversion of long-lived platform trough. In our case, this trough inherited the Riphean Kaltasy Aulacogen. Together with the unilateral, probably, reverse-fault-line (?) Ufa Horst, the Tulva Swell is situated opposite to the area of maximum near-latitudinal compression of the recent Urals (the socalled Ufa amphitheater, or Central Ural pinch) and along with other within-plate arches similar in structure—Bugul’ma-Belebei and Obschii Syrt—marks a zone of neotectonic reactivation of the Russian Plate near the Urals.