BHαBAR: big Hα kinematical sample of barred spiral galaxies – I. Fabry–Perot observations of 21 galaxies

We present the Hα gas kinematics of 21 representative barred spiral galaxies belonging to the BHαBAR sample. The galaxies were observed with FaNTOmM, a Fabry–Perot integral-field spectrometer, on three different telescopes. The three-dimensional data cubes were processed through a robust pipeline with the aim of providing the most homogeneous and accurate data set possible useful for further analysis. The data cubes were spatially binned to a constant signal-to-noise ratio, typically around 7. Maps of the monochromatic Hα emission line and of the velocity field were generated and the kinematical parameters were derived for the whole sample using tilted-ring models. The photometrical and kinematical parameters (position angle of the major axis, inclination, systemic velocity and kinematical centre) are in relative good agreement, except perhaps for the later-type spirals.     

GRB sky distribution puzzles

We analyze the randomness of the sky distribution of cosmic gamma-ray bursts. These events are associated with massive galaxies, spiral or elliptical, and therefore their positions should trace the large-scale structure, which, in turn, could show up in the sky distribution of fluctuations of the cosmicmicrowave background (CMB). We test this hypothesis by mosaic correlation mapping of the distributions of CMB peaks and burst positions, find the distribution of these two signals to be correlated, and interpret this correlation as a possible systematic effect.     

Model Radiants of the Geminid Meteor Shower

This paper describes the final stage of the study of the Geminid meteoroid stream formation and evolution using the nested polynomials method reported by Ryabova (in: Warmbein (ed.) Meteoroids 2001, Proc. of the Internat. Conf., Kiruna, Sweden, 6–10 August 2001; MNRAS 375:1371–1380, 2007). In the previous work we discussed possibility to calibrate the model using the shape of the model activity profiles and configuration of orbital parameters. Here we show that the radiant structure also could be utilized for this purpose, since the model radiant structure has a very specific pattern. Model area of radiation does not have a “classical” prolate linear shape, and the configuration of activity centers has a “V” shape. During one night of simulated observations several activity centers could be observed. The model produced maps of the velocity distribution in the radiant area.     

Integrated Research of the Southeastern Baltic Sea during the Cruise 47 of the R/V Akademik Nikolaj Strakhov

Oceanology - New data on the geological structure and genesis of relict bottom relief forms, objects of underwater cultural heritage, and the structure of bottom sediments in the Baltic Sea were...     

Minimizing structural vibrations with absorbers

In a companion paper¹ the authors show that the parameters of an absorber which will minimize the resonant response of a simple elastic body can be determined from known results by treating the body as an equivalent single degree-of-freedom system. In this paper cylindrical shells are considered as examples of dynamically complex structures, for which the ratio of the natural frequencies of adjacent modes tends towards unity. It is shown that as dynamic complexity increases optimum absorber parameters for the reduction of resonant response deviate increasingly from those for an equivalent single degree-of-freedom system. Absorbers can be used also to reduce the random response of structures. Simple expressions for optimum parameters are given for an undamped main system, which has one degree of freedom and is subjected to white noise excitation. Optimum absorber parameters for beams, plates and cylindrical shells show similar qualitative behaviour for random and harmonic response with the concept of an equivalent single degree-of-freedom system being applicable only for the simpler structures.     

Sorption–Desorption Transformation of the Runoff of Dissolved Microelements at River–Sea Geochemical Barrier (Based on Data of Experimental Laboratory Simulation)

Water Resources - A new method was used for experimental simulation of the sorption–desorption transformation of microelement composition of the adsorbed complex of solid substances of river...     

On Geoseismic Noise and Helioseismic Oscillations

Izvestiya, Physics of the Solid Earth - Abstract—In their paper published in Izvestiya, Physics of the Solid Earth, G.A. Sobolev et al. (2020) discussed the results of their study. Firstly,...     

Solar limb darkening in the wings of the CaII H and K lines

The method for measuring solar limb darkening has been proposed, and the formulas, describing the law of solar limb darkening in the wings of the CaII H (396.849 nm) and K (393.369 nm) lines, have been derived. To operate at arbitrary points on the Sun’s surface, it is necessary to know the law of solar limb darkening, which is specific in different spectral regions. The procedure of spectrum correction for a flat field, proposed in our previous works, is based on comparing line-free spectral regions with the solar center reference spectrum from the atlas by Brault and Neckel [1994].