Star Formation in Nearby Isolated Galaxies

We use the FUV fluxes measured with the GALEX to study the star formation properties of galaxies collected in the "Local Orphan Galaxies" catalog (LOG). Among 517 LOG galaxies having radial velocities V(LG) < 3500 km/s and Galactic latitudes |b|> 15 degr, 428 objects have been detected in FUV. We briefly discuss some scaling relations between the specific star formation rate (SSFR) and stellar mass, HI-mass, morphology, and surface brightness of galaxies situated in extremely low density regions of the Local Supercluster. Our sample is populated with predominantly late-type, gas-rich objects with the median morphological type of Sdm. Only 5% of LOG galaxies are classified as early types: E, S0, S0/a, however, they systematically differ from normal E and S0 galaxies by lower luminosity and presence of gas and dust. We find that almost all galaxies in our sample have their SSFR below 0.4 [Gyr^{-1}]. This limit is also true even for a sample of 260 active star-burst Markarian galaxies situated in the same volume. The existence of such a quasi-Eddington limit for galaxies seems to be a key factor which characterizes the transformation of gas into stars at the current epoch.Comment: 10 pages, 8 figures, 3 table

X-ray AGN in the XMM-LSS galaxy clusters: no evidence of AGN suppression

We present a study of the overdensity of X-ray selected AGN in 33 galaxy clusters in the XMM-LSS field, up to redhift z=1.05. Previous studies have shown that the presence of X-ray selected AGN in rich galaxy clusters is suppressed. In the current study we investigate the occurrence of X-ray selected AGN in low and moderate X-ray luminosity galaxy clusters. Due to the wide contiguous XMM-LSS survey area we are able to extend the study to the cluster outskirts. We therefore determine the projected overdensity of X-ray point-like sources out to 6r_{500} radius. To provide robust statistical results we also use a stacking analysis of the cluster projected overdensities. We investigate whether the observed X-ray overdensities are to be expected by estimating also the corresponding optical galaxy overdensities. We find a positive X-ray projected overdensity at the first radial bin, which is however of the same amplitude as that of optical galaxies. Therefore, no suppression of X-ray AGN activity with respect to the field is found, implying that the mechanisms responsible for the suppression are not so effective in lower density environments. After a drop to roughly the background level between 2 and 3r_{500}, the X-ray overdensity exhibits a rise at larger radii, significantly larger than the corresponding optical overdensity. Finally, using redshift information of all optical counterparts, we derive the spatial overdensity profile of the clusters. We find that the agreement between X-ray and optical overdensities in the first radial bin is also suggested in the 3-dimensional analysis. However, we argue that the X-ray overdensity "bump" at larger radial distance is probably a result of flux boosting by gravitational lensing of background QSOs. For high redshift clusters an enhancement of X-ray AGN activity in their outskirts is still possible.Comment: 16 pages. Accepted for publication in A&

Research of surface roughness at magnetically-abrasive treatment of details made of magnetically soft alloys

У статті розглянуто результати експериментальних досліджень з вивчення параметрів шорсткості оброблюваної поверхні магнітно–абразивним методом. Запропоновано рекомендації з вибору основних технологічних параметрів оброблення цим методом для отримання заданих кресленням параметрів шорсткості поверхні.The results of experimental researches the purpose of which was to learn the parameters of roughness of the processed surface are considered in the article of magnito-abrasive method. As a result of processing of experimental data recommendations were offered, on the choice of basic technological parameters of treatment this method for the receipt of by a draft preset the parameter of roughness of surface

The mechanisms of social norms’ influence on consumer decision making:A Meta-analysis

In the past decades, marketing practitioners have embraced social norms as a powerful instrument of influencing consumers' behavior. An important distinction has been made between descriptive norms (what most others do) and injunctive norms (what others approve of), and this meta-analysis across 297 studies examines the effects of these types of social norms on consumer decision-making processes. We argue that descriptive norms directly influence behavior, and consequently that their effect on behavior should be stronger than that of injunctive norms. Injunctive norms, by contrast, should be more strongly related to intentions than descriptive norms. Results of the meta-analysis support these predictions, and furthermore provide new insights into the moderating effects of aspects of the norm (specificity of the norm, norm source) and of the target person (gender, age)