Orbital parameters of V 0332+53 from 2015 giant outburst data

We present the updated orbital solution for the transient Be X-ray binary V 0332+53 comple- menting historical measurements with the data from the gamma-ray burst monitor onboard Fermi obtained during the outburst in June-October 2015. We model the observed changes in the spin- frequency of the pulsar and deduce the orbital parameters of the system. We significantly improve existing constrains and show that contrary to the previous findings no change in orbital parameters is required to explain the spin evolution of the source during the outbursts in 1983, 2005 and 2015. The reconstructed intrinsic spin-up of the neutron star during the latest outburst is found to be comparable with previosly observed values and predictions of the accretion torque theory.Comment: 3 pages, 2 figures, submitted to A&

Reactions of p-Nitrophenyloxirane with Amines Containing Fragments with Bicyclic Skeleton

Reactions of p-nitrophenyloxirane with amines containing fragments with bicyclic skeleton of norbornene, norbornane, epoxynorbornane (stereoisomeric exo- and endo-5-aminomethylbicyclo[2.2.1]hept-2-enes, N-benzyl-endo-5-aminomethylbicyclo[2.2.1]hept-2-ene, endo-5-(2-aminoethyl)bicyclo[2.2.1]hept-2-ene, stereoisomeric exo- and endo-2-aminomethylbicyclo[2.2.1]heptanes, 2-(1-aminoethyl)bicyclo[2.2.1]-heptane, exo-5-aminomethyl-exo-2,3-epoxybicyclo[2.2.1]heptane) were investigated. The aminolysis of pnitrophenyloxirane occurred regioselectively according to Krasusky rule as was proved by 1H and 13C NMR data. As shown by 1H and 13C NMR spectroscopy the oxyalkylation product obtained from N-benzyl-endo-5-aminomethylbicyclo[2.2.1]hept-2-ene was composed of two diastereomers originating from the presence of a chiral nitrogen atom in the rear part of the rigid bicyclic skeleton. New products of amino groups transformation in the molecules of hydroxyamines were obtained by reaction with p-methylbenzoyl chloride and p-nitrophenylsulfonyl chloride. Regioselectivity of the attack of electrophilic reagents on the nitrogen in the hydroxyamines was confirmed by IR and 1H NMR spectra of the products. The data on pharmacological activity tests of N-2-hydroxyethyl(p-nitrophenyl)-5-aminomethylbicyclo[2.2.1]hept-2-ene are reported

Population of persistent high mass X-ray binaries in the Milky Way

We present results of the study of persistent high mass X-ray binaries (HMXBs) in the Milky Way, obtained from the deep INTEGRAL Galactic plane survey. This survey provides us a new insight into the population of high mass X-ray binaries because almost half of the whole sample consists of sources discovered with INTEGRAL. It is demonstrated for the first time that the majority of persistent HMXBs have supergiant companions and their luminosity function steepens somewhere around ~2x10^{36} erg/s. We show that the spatial density distribution of HMXBs correlates well with the star formation rate distribution in the Galaxy. The vertical distribution of HMXBs has a scale-height h~85 pc, that is somewhat larger than the distribution of young stars in the Galaxy. We propose a simple toy model, which adequately describes general properties of HMXBs in which neutron stars accrete a matter from the wind of the its companion (wind-fed NS-HMXBs population). Using the elaborated model we argue that a flaring activity of so-called supergiant fast X-ray transients, the recently recognized sub-sample of HMXBs, is likely related with the magnetic arrest of their accretion.Comment: 17 pages, 12 figures, accepted for publicatiopn in MNRA