Are polar rings indeed polar?

We have considered polar ring galaxy candidates, the images of which can be found in the SDSS. The sample of 78 galaxies includes the most reliable candidates from the SPRC and PRC catalogs, some of which already have kinematic confirmations. We analyze the distributions of studied objects by the angle between the polar ring and the central disk, and by the optical diameter of the outer ring structures. In the vast majority of cases, the outer structures lie in the plane close to polar (within 10-20 deg) which indicates the stability of the corresponding orbits in the gravitational potential of the halo. Moderately inclined outer structures are observed only in about 6% of objects which probably indicates their short lifetime. In such an unstable configuration, the polar ring would often cross the disk of the galaxy, being smaller than it in the diameter. We show that the inner polar structures and outer large-scale polar rings form a single family in the distribution of diameters normalized to the optical size of the galaxy. At the same time, this distribution is bimodal, as the number of objects with d_ring= (0.4-0.7)*d_disk is negligible. Such a shape of size distribution is most likely due to the fact that the stability of polar orbits in the inner regions of galaxies is maintained by the bulge or the bar, while in the outer regions it is provided by the spheroidal (or triaxial) halo.Comment: Corrected version accepted in Astrophysical Bulletin, 8 pages, 5 EPS figure

Photon storage in Lambda-type optically dense atomic media. III. Effects of inhomogeneous broadening

In a recent paper [Gorshkov et al., Phys. Rev. Lett. 98, 123601 (2007)] and in the two preceding papers [Gorshkov et al., Phys. Rev. A 76, 033804 (2007); 76, 033805 (2007)], we used a universal physical picture to optimize and demonstrate equivalence between a wide range of techniques for storage and retrieval of photon wave packets in homogeneously broadened Lambda-type atomic media, including the adiabatic reduction of the photon group velocity, pulse-propagation control via off-resonant Raman techniques, and photon-echo-based techniques. In the present paper, we generalize this treatment to include inhomogeneous broadening. In particular, we consider the case of Doppler-broadened atoms and assume that there is a negligible difference between the Doppler shifts of the two optical transitions. In this situation, we show that, at high enough optical depth, all atoms contribute coherently to the storage process as if the medium were homogeneously broadened. We also discuss the effects of inhomogeneous broadening in solid state samples. In this context, we discuss the advantages and limitations of reversing the inhomogeneous broadening during the storage time, as well as suggest a way for achieving high efficiencies with a nonreversible inhomogeneous profile.Comment: 15 pages, 8 figures. V2: minor changes in presentation, new references, higher resolution of figure

Hyperostosis Frontalis Interna on the Skeletal Remains of the Sarmatians of the Lower Volga and the Lower Don (to the Question of Causes of the Endocrine Disorders in the Early Iron Age)

Introduction. The field of paleopathology, which studies the diseases of ancient people, makes important contribution to the reconstruction of the lifestyle and history of the Sarmatian nomads. When examining human bone remains, such a pathological condition as the hyperostosis frontalis interna (HFI) is sometimes revealed on the frontal bone from the endocranium. Today, most physisians and paleopathologists believe that this condition is the result of the Morgagni-Stewart-Morel syndrome, which stimulates the development of endocrine disorders in the human body. Methods and materials. The research material is represented with the skulls of Sarmatian nomads from the burial grounds of the Lower Volga and the Lower Don. A total of 465 craniums have been examined. The degree of frontal hyperostosis development has been assessed by the method of I. Hershkovitz, et al. Analysis. As a result of the analysis of bone material, 35 cases of the HFI have been recorded on the Sarmatian skulls. Genetic predisposition, specific lifestyle (nomadism), unhealthy and unsystematic diet (high content of proteins and fats, periods of hunger alternated with overeating periods), psycho-emotional disorders typical of the nomads of the early Iron Age were, most likely, the determining factors stimulating the development of endocrine disorders markers. Results. We’ve come to the conclusion that, as opposed to the modern character of the disease spreading, which is more typical for women aged 45-60, this deviation in Sarmatians is more common in men. The analysis of written, ethnographical and archaeological sources, the study of medical and paleopathological literature allows assuming that the HFI in the Sarmatians of the Lower Volga and the Lower Don could develop as a result of the abovementioned factors. E. V. Pererva has carried out the the paleopathological study of materials and the comparison of the obtained results with domestic and foreign works in the field of medicine and anthropology. V. I. Moiseev has interpreted the obtained results in the context of written and archaeological sources