52 research outputs found
Surface photometry of 50 dwarf galaxies in the Local Volume
Results of surface photometry of 50 galaxies in the Local Volume based on
archived images obtained with the Hubble Space Telescope are presented.
Integrated magnitudes in the V and I bands are introduced for the sample
galaxies, along with brightness and color profiles. The obtained photometric
parameters are compared with the measurements of other authors.Comment: 12 pages, 1 figure, 1 tabl
Structure of hyper-branched polyester polyol BOLTORN H2O-COOH. NMR data
The methods of one- and two-dimensional 1H and 13C NMR spectroscopy have been used to study the structure of hyper-branched polyester polyol BOLTORN H2O-COOH and complex Co12[BH20(COOH)] on its basis. It was shown that both compounds have non-stereoregular structure. Paramagnetic ions Co(II) are coordinated both on the surface of the molecule and near the core. © 2010 Pleiades Publishing, Ltd
Data of one-and two-dimensional NMR spectroscopy in the study of structure and nature of associations of hyperbranched polyester polyol BOLTORN H20-OH
Structure of the hyperbranched polyester of the polyol BOLTORN H20-OH was studied by oneand two-dimensional 1H and 13C NMR spectroscopy in combination with the IR spectroscopy and semiempirical quantum-chemical calculations (method AM1). The polyol structure was shown not to be stereoregular. Three basic types of H-bonding interactions of intra-or intermolecular nature were revealed: C=O...HO, OH...OH, and C=O...HO...HO. © Pleiades Publishing, Ltd., 2010
Formation of a polynuclear cobalt(II) complex on a polydentate nanoplatform of carboxylated boltorn H20
A method of synthesis of a polynuclear cobalt(II) complex with carboxylated Boltorn H20, a hyperbranched polyol of second generation, has been suggested. The logarithm of stability constant and the composition of the complex species BH20(OC(O)CH 2CH 2COO) 12Co 12 in a 50% acetone solution have been calculated from the electronic absorption spectra: logβ = 13.7 ± 0.2 and the composition M : L = 12 : 1. The IR spectroscopy and NMR ( 13C and 1H) point to the coordination of Co(II) ions not only at the surface of the molecule but also near its core. © Pleiades Publishing, Ltd., 2012
The Stellar Content of the Polar Rings in the Galaxies NGC 2685 and NGC 4650A
We present the results of stellar photometry of polar-ring galaxies NGC 2685
and NGC 4650A, using the archival data obtained with the Hubble Space
Telescope's Wide Field Planetary Camera 2. Polar rings of these galaxies were
resolved into ~800 and ~430 stellar objects in the B, V and Ic bands,
considerable part of which are blue supergiants located in the young stellar
complexes. The stellar features in the CM-diagrams are best represented by
isochrones with metallicity Z = 0.008. The process of star formation in the
polar rings of both galaxies was continuous and the age of the youngest
detected stars is about 9 Myr for NGC 2685 and 6.5 Myr for NGC 4650A.Comment: 21 pages, 9 figures, AJ 2004 February, accepte
Study of the structure and kinematics of the NGC 7465/64/63 triplet galaxies
This paper is devoted to the analysis of new observational data for the group
of galaxies NGC 7465/64/63, which were obtained at the 6-m telescope of the
Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS)
with the multimode instrument SCORPIO and the Multi Pupil Fiber Spectrograph.
For one of group members (NGC 7465) the presence of a polar ring was suspected.
Large-scale brightness distributions, velocity and velocity dispersion fields
of the ionized gas for all three galaxies as well as line-of-sight velocity
curves on the basis of emission and absorption lines and a stellar velocity
field in the central region for NGC 7465 were constructed. As a result of the
analysis of the obtained information, we revealed an inner stellar disk (r ~
0.5 kpc) and a warped gaseous disk in addition to the main stellar disk, in NGC
7465. On the basis of the joint study of photometric and spectral data it was
ascertained that NGC 7464 is the irregular galaxy of the IrrI type, whose
structural and kinematic peculiarities resulted most likely from the
gravitational interaction with NGC 7465. The velocity field of the ionized gas
of NGC 7463 turned out typical for spiral galaxies with a bar, and the bending
of outer parts of its disk could arise owing to the close encounter with one of
galaxies of the environment.Comment: 20 pages, 6 figure
Chiral and axial anomalies in the framework of generalized Hamiltonian BFV-quantization
The regularization scheme is proposed for the constrained Hamiltonian
formulation of the gauge fields coupled to the chiral or axial fermions. The
Schwinger terms in the regularized operator first-class constraint algebra are
shown to be consistent with the covariant divergence anomaly of the
corresponding current. Regularized quantum master equations are studied, and
the Schwinger terms are found out to break down both nilpotency of the
BRST-charge and its conservation law. Wess-Zumino consistency conditions are
studied for the BRST anomaly and they are shown to contradict to the covariant
Schwinger terms in the BRST algebra.Comment: LaTeX, 24p
Ground-based acoustic parametric generator impact on the atmosphere and ionosphere in an active experiment
We develop theoretical basics of active experiments with two beams of acoustic waves, radiated by a ground-based sound generator. These beams are transformed into atmospheric acoustic gravity waves (AGWs), which have parameters that enable them to penetrate to the altitudes of the ionospheric E and F regions where they influence the electron concentration of the ionosphere. Acoustic waves are generated by the ground-based parametric sound generator (PSG) at the two close frequencies. The main idea of the experiment is to design the output parameters of the PSG to build a cascade scheme of nonlinear wave frequency downshift transformations to provide the necessary conditions for their vertical propagation and to enable penetration to ionospheric altitudes. The PSG generates sound waves (SWs) with frequencies f1 = 600 and f2 = 625 Hz and large amplitudes (100-420ms-1). Each of these waves is modulated with the frequency of 0.016 Hz. The novelty of the proposed analytical-numerical model is due to simultaneous accounting for nonlinearity, diffraction, losses, and dispersion and inclusion of the two-stage transformation (1) of the initial acoustic waves to the acoustic wave with the difference frequency Δf = f2 - f1 in the altitude ranges 0-0.1 km, in the strongly nonlinear regime, and (2) of the acoustic wave with the difference frequency to atmospheric acoustic gravity waves with the modulational frequency in the altitude ranges 0.1-20 km, which then reach the altitudes of the ionospheric E and F regions, in a practically linear regime. AGWs, nonlinearly transformed from the sound waves, launched by the two-frequency ground-based sound generator can increase the transparency of the ionosphere for the electromagnetic waves in HF (MHz) and VLF (kHz) ranges. The developed theoretical model can be used for interpreting an active experiment that includes the PSG impact on the atmosphere-ionosphere system, measurements of electromagnetic and acoustic fields, study of the variations in ionospheric transparency for the radio emissions from galactic radio sources, optical measurements, and the impact on atmospheric aerosols. The proposed approach can be useful for better understanding the mechanism of the acoustic channel of seismo-ionospheric coupling
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