Searches for Ultra-Compact Dwarf Galaxies in Galaxy Groups

We present the results of a search for ultra-compact dwarf galaxies (UCDs) in six different galaxy groups: Dorado, NGC1400, NGC0681, NGC4038, NGC4697 and NGC5084. We searched in the apparent magnitude range 17.5 < b_j < 20.5 (except NGC5084: 19.2 < b_j < 21.0). We found 1 definite plus 2 possible UCD candidates in the Dorado group and 2 possible UCD candidates in the NGC1400 group. No UCDs were found in the other groups. We compared these results with predicted luminosities of UCDs in the groups according to the hypothesis that UCDs are globular clusters formed in galaxies. The theoretical predictions broadly agree with the observational results, but deeper surveys are needed to fully test the predictions.Comment: 8 pages, 2 figures, accepted for publication in MNRA

Internal properties of ultracompact dwarf galaxies in the Virgo cluster

We present new imaging and spectroscopic observations of six ultracompact dwarf (UCD) galaxies in the Virgo Cluster, along with reanalyzed data for five Fornax Cluster UCDs. These are the most luminous UCDs: -14 mag < M-V < -12 mag. Our Hubble Space Telescope imaging shows that most of the UCDs have shallow or steep cusps in their cores; only one UCD has a flat "King'' core. None of the UCDs show tidal cutoffs down to our limiting surface brightness. Spectroscopic analysis shows that Virgo UCDs are old ( older than 8 Gyr) and have metallicities in the range from [Z/H] = -1.35 to +0.35 dex. Five Virgo UCDs have supersolar [alpha/Fe] abundance ratios, and one Virgo UCD has a solar abundance ratio. The supersolar [alpha/Fe] abundances are typical of old stellar populations found in globular clusters and elliptical galaxies. We find that Virgo UCDs have structural and dynamical properties similar to Fornax UCDs. The Virgo and Fornax UCDs all have masses approximate to(2-9) x 10(7) M-circle dot and mass-to-light ratios approximate to(3-5) M-circle dot/L-circle dot,(V). The dynamical mass-to-light ratios for Virgo UCDs are consistent with simple stellar population model predictions: the Virgo UCDs do not require dark matter to explain their mass-to-light ratios. We conclude that the internal properties of Virgo UCDs are consistent with them being the high-mass/high-luminosity extreme of known globular cluster populations. We refrain from any firm conclusions on Fornax UCD origins until accurate age, metallicity, and alpha-abundance estimates are obtained for them. Some of our results, notably the fundamental plane projections, are consistent with the formation of UCDs by the simple removal of the halo from the nuclei of nucleated dwarf galaxies. However, the ages, metallicities, and abundances for Virgo UCDs are not consistent with this simple stripping model. It might be consistent with more sophisticated models of the stripping process that include the effects of gas removal on the chemical evolution of the nuclei

The charge state of pt in binary compounds and synthetic minerals determined by x-ray absorption spectroscopy and quantum chemical calculations

The binary synthetic compounds of Pt with chalcogens (O, S, Se, Te), pnictogens (As, Sb, Bi), and intermetallic compounds with Ga, In, and Sn of various stoichiometry were studied via X-ray absorption spectroscopy (XAS). The partial atomic charges of Pt in the compounds were computed using quantum chemical density functional theory (DFT) based methods: the Bader (QTAIM) method, and the density-derived electrostatic and chemical (DDEC6) approach. Strong positive correlations were established between the calculated partial atomic charges of Pt and the electronegativity (χ) of ligands. The partial charge of Pt in PtL2 compounds increases much sharply when the ligand electronegativity increases than the Pt partial charge in PtL compounds. The effect of the ligand-to-Pt atomic ratio on the calculated Pt partial charge depended on ligand electronegativity. The DDEC6 charge of Pt increases sharply with the growth of the number of ligands in PtSn (n = 1, 2; electronegativity χ(S) &gt;&gt; χ(Pt)), weakly depends on the phase composition in PtTen (n = 1, 2; χ(Te) is slightly lower than χ(Pt)), and decreases (becomes more negative) with increase of the ligand-to-Pt ratio in intermetallic compounds with electron donors (χ(L) &lt; χ(Pt), L = Ga, In, Sn). According to XANES spectroscopy, the number of 5d (L2,3 absorption edges) and 6p (L1-edge) electrons at the Pt site decreased when ligand electronegativity increased in chalcogenides and pnictides groups. An increase of the ligand-to-Pt ratio resulted in the increase of the Pt L3-edge white line intensity and area in all studied compounds. In the case of chalcogenides and pnictides, this behavior was consistent with the electronegativity rule as it indicated a loss of Pt 5d electrons caused by the increase of the number of ligands, i.e., acceptors of electrons. However, in the case of ligands–electron donors (Te, Sn, Ga, In) this observation is in apparent contradiction with the electronegativity arguments as it indicates the increase of the number of Pt 5d-shell vacancies (holes) with the increase of the number of the ligands, for which the opposite trend is expected. This behavior can be explained in the framework of the charge compensation model. The loss of the Pt d-electrons in compounds with low ligand electronegativity (χ(Pt) &gt; χ(L)) was overcompensated by the gain of the hybridized s-p electron density, which was confirmed by Pt L1-edge spectra analysis. As a result, the total electron density at the Pt site followed the electronegativity rule, i.e., it increased with the growth of the number of the ligands-electron donors. The empirical correlations between the Pt partial atomic charges and parameters of XANES spectral features were used to identify the state of Pt in pyrite, and can be applied to determine the state of Pt in other ore minerals. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This study was supported by RFBR grant No. 20-35-70049, the program 211 of the Russian Federation Government, agreement No. 02.A03.21.0006, by the Russian Government Program of Competitive Growth of Kazan Federal University, and by Ministry of Education and Science of the Russian Federation grant No. 075-15-2020-802

Testing Newtonian Gravity with AAOmega: Mass-to-Light Profiles of Four Globular Clusters

Testing Newtonian gravity in the weak-acceleration regime is vital to our understanding of the nature of the gravitational interaction. It has recently been claimed that the velocity dispersion profiles of several globular clusters flatten out at large radii, reminiscent of galaxy rotation curves, even though globular clusters are thought to contain little or no dark matter. We investigate this claim, using AAOmega observations of four globular clusters, namely M22, M30, M53 and M68. M30, one such cluster that has had this claim made for its velocity dispersion, was included for comparison with previous studies. We find no statistically significant flattening of the velocity dispersion at large radii for any of our target clusters and therefore we infer the observed dynamics do not require that globular clusters are dark matter dominated, or a modification of gravity. Furthermore, by applying a simple dynamical model we determine the radial mass-to-light profiles for each cluster. The isothermal rotations of each cluster are also measured, with M22 exhibiting clear rotation, M68 possible rotation and M30 and M53 lacking any rotation, within the uncertainties.Comment: 7 pages, 4 figures and two tables. Accepted by MNRA

Environmental Dependence of the Structure of Brightest Cluster Galaxies

We measure the Petrosian structural properties of 33 brightest cluster galaxies (BCGs) at redshifts z<0.1 in X-ray selected clusters with a wide range of X-ray luminosities. We find that some BCGs show distinct signatures in their Petrosian profiles, likely to be due to cD haloes. We also find that BCGs in high X-ray luminosity clusters have shallower surface brightness profiles than those in low X-ray luminosity clusters. This suggests that the BCGs in high X-ray luminosity clusters have undergone up to twice as many equal-mass mergers in their past as those in low X-ray luminosity clusters. This is qualitatively consistent with the predictions of hierarchical structure formation.Comment: 11 pages, accepted for publication in MNRA

Norbornadiene as a Universal Substrate for Organic and Petrochemical Synthesis

A wide range of rare polycyclic hydrocarbons can be obtained through catalytic processes involving  norbornadiene (NBD). The problem of selectivity is crucial for such reactions. The feasibility of controlling selectivity and reaction rate has been shown for cyclic dimerization, co-dimerization, isomerization and allylation of NBD. Kinetic rules have been scrutinized. Consistent mechanisms have been proposed. Factors affecting directions of the reactions and allowing us to obtain individual stereoisomers quantitatively, have been established. A series of novel unsaturated compounds has been synthesized; they incorporate a set of double bonds with different reactivity and can find an extremely wide range of applications

Resolved Spectroscopy of Gravitationally-Lensed Galaxies: Recovering Coherent Velocity Fields in Sub-Luminous z~2-3 Galaxies

We present spatially-resolved dynamics for six strongly lensed star-forming galaxies at z=1.7-3.1, each enlarged by a linear magnification factor ~8. Using the Keck laser guide star AO system and the OSIRIS integral field unit spectrograph we resolve kinematic and morphological detail in our sample with an unprecedented fidelity, in some cases achieving spatial resolutions of ~100 pc. With one exception our sources have diameters ranging from 1-7 kpc, star formation rates of 2-40 Msun/yr (uncorrected for extinction) and dynamical masses of 10^(9.7-10.3) Msun. With this exquisite resolution we find that four of the six galaxies display coherent velocity fields consistent with a simple rotating disk model, which can only be recovered with the considerably improved spatial resolution and sampling from the combination of adaptive optics and strong gravitational lensing. Our model fits imply ratios for the systemic to random motion, V sin(i)/sigma, ranging from 0.5-1.3 and Toomre disk parameters Q<1. The large fraction of well-ordered velocity fields in our sample is consistent with data analyzed for larger, more luminous sources at this redshift. Our high resolution data further reveal that all six galaxies contain multiple giant star-forming HII regions whose resolved diameters are in the range 300 pc - 1.0 kpc, consistent with the Jeans length expected in the case of dispersion support. The density of star formation in these regions is ~100 times higher than observed in local spirals; such high values are only seen in the most luminous local starbursts. The global dynamics and demographics of star formation in these HII regions suggest that vigorous star formation is primarily governed by gravitational instability in primitive rotating disks.Comment: 18 pages, 8 figures, submitted to MNRA

Image-Subtraction Photometry of the Globular Cluster M3: identification of new double-mode RR Lyrae stars

We have applied the image subtraction method to the M3 dataset previously analyzed by Corwin & Carney (2001; CC01). The new analysis produced light curves and periods for 15 variables, bringing to 222 the total number of RR Lyrae stars in CC01 M3 dataset. We have identified three new candidate double-mode (RRd) variables (V13, V200, and V251) in M3. Of the newly discovered RRd's V13 is unusual in that it has the fundamental as the dominant pulsation mode. Two of the new candidate RRd's (V13 and V200) have period ratios as low as 0.738-0.739. They lie separated from all previously known RRd's in the Petersen diagram, in positions implying a large spread in mass and/or, less likely, in heavy element mass fraction, among the M3 horizontal branch (HB) stars. We explore mass transfer and helium enhancement as possible explanations for the apparent spread in HB masses. We also note that the masses derived from the RRd analyses now favor little mass loss on the red giant branch. V200 has changed its dominant pulsation mode from fundamental to first overtone, while V251 has changed its dominant mode from first overtone to fundamental in the interval 1992 to 1993. Together with M3-V166 this is the first time that RRd variables are observed to switch their dominant pulsation modes while remaining RRd's. The phenomenon is found to occur in a one year time-span thus suggesting that these stars are undergoing a rapid evolutionary phase, and that both redward and blueward evolution may take place among the HB stars in M3. The unusual behavior of the M3 RRd's is discussed and compared to that of the RRd's identified so far in globular clusters and in the field of our and other Local Group galaxies. We find lack of correlation between the presence of RRd variables and any of the cluster structural parameters.Comment: 38 pages, 16 figures, AJ in pres

Detection and treatment of osteoporosis at the patients of 50 years and elder with fracture of forearm

Introduction: fracture of distal part of forearm at a low level of a trauma with women in the age of 50 and elder is the index to osteoporosis and serves as a criterion for beginning of therapy. However, osteoporosis isn’t often diagnosed and treated with patients with such localization of fracture. The purpose: to estimate of detection and treatment of osteoporosis at the patients of senior age group with fracture of distal part of forearm and influence of traumatologist's recommendations on their changes. Materials and methods: 121 women in the age of 50 years and elder, who have fracture of distal part of forearm, have been included in this study. The patients of intervention group (56 patients, the median age was 61,3 ± 8,6) received information about osteoporosis, assignment to densitometry and recommendation by treatment from traumatologist. The patients of control group (65 patients, the median age was 63,5±8,1) were conducted as it was established in practice of the department of traumatology. There was a questioning of all patients who had been included in investigation after 6 months since fracture. Results: densitometry was performed to 26 (46,4%) patients of intervention group and 2 (3,1%) patients of control group, р<0,0001.38 (67,9%) patients of intervention group and 25 (38.5%) patients of control group began conservative treatment, p=0,001.38 (67,9%) patients of intervention group and 23 (35,4%) patients of control group began to take calcium and 03, p<0,001.7 (12,5%) patients of intervention group and 2 (3,1%) patients of control group began the treatment with pathogenetic medication, p=0.05.41 patients stopped the treatment: 18 (47,4%) patients from 38 who had begun the investigation of intervention group and 23 (92,0%) from 25 patient of control group, p=0,0001. Conclusion: the patients with fracture of distal part of forearm at a low level of a trauma concern to group of the high risk of osteoporosis, but most of them remain without corresponding examination and treatment. Active position of traumatologist on detection and treatment of osteoporosis raise the number of patients with diagnostical and treated osteoporosis.Введение: Перелом дистального отдела предплечья (ПДОП) при низком уровне травмы у женщин старше 50 лет является маркером остеопороза (0П) и критерием для начала терапии. Однако часто у пациентов с переломом данной локализации PП не диагностируется и не лечится. Цель: оценить выявляемость и лечение OП у пациентов старших возрастных групп с ПДОП и влияние рекомендаций травматолога на их изменение. Материалы и методы: В исследование включена 121 женщина в возрасте 50 лет и старше с ПДОП. Пациентки основной группы (56 чел., ср. возраст 61,3 ± 8,6 года) получали информацию от травматолога об 0П, направление на денситометрию и рекомендации по лечению. Пациентки контрольной группы (65 чел., ср. возраст 63,5 ± 8,1 года) велись так, как зто заведено в практике данного травмпункта. Спустя 6 месяцев после перелома был проведен опрос всех включенных в исследование пациентов. Результаты: Денситометрия была выполнена у 26 (46,4%) пациенток основной и 2 (3,1%) пациенток контрольной групп, р<0,0001. В основной группе консервативное лечение начали 38 (67,9%) чел, в контрольной - 25 (38,5%) чел, р=0,001. Препараты кальция и D3 начали принимать 38 (67,9%) пациенток основной и 23 (35,4%) пациентки контрольной групп, р<0,001. Лечение препаратами патогенетического действия начали 7 (12,5%) чел. основной и 2 (3,1%) чел. контрольной групп, р=0,05. Прекратили лечение на момент расспроса 41 чел.: в основной группе -18 (47,4%) чел. из 38 начавших его, в контрольной группе из 25 начавших - 23 чел (92,0%), р=0,0001. Выводы: пациенты, перенесшие перелом луча при низком уровне травмы относятся к группе повышенного риска OП, однако большинство пациентов остаются без соответствующего обследования и лечения. Активная позиция травматолога по выявлению и лечению OП повышает число пациентов с диагностированным и леченным OП

Inner Polar Rings and Disks: Observed Properties

A list of galaxies with inner regions revealing polar (or strongly inclined to the main galactic plane) disks and rings is compiled from the literature data. The list contains 47 galaxies of all morphological types, from E to Irr. We consider the statistics of the parameters of polar structures known from observations. The radii of the majority of them do not exceed 1.5 kpc. The polar structures are equally common in barred and unbarred galaxies. At the same time, if a galaxy has a bar (or a triaxial bulge), this leads to the polar disk stabilization - its axis of rotation usually coincides with the major axis of the bar. More than two thirds of all considered galaxies reveal one or another sign of recent interaction or merging. This fact indicates a direct relation between the external environment and the presence of an inner polar structure.Comment: 12 pages, 3 figures, accepted to Astrophysical Bulletin. Minor changes and corrections are still possibl