INTEGRAL broadband spectroscopy of Vela X-1

The wind-accreting X-ray binary pulsar and cyclotron line source Vela X-1 has been observed extensively during INTEGRAL Core Program observations of the Vela region in June-July and November-December 2003. In the latter set of observations the source showed intense flaring -- see also Staubert et al. (2004), these proceedings. We present early results on time averaged and time resolved spectra, of both epochs of observations. A cyclotron line feature at ~53 keV is clearly detected in the INTEGRAL spectra and its broad shape is resolved in SPI spectra. The remaining issues in the calibration of the instruments do not allow to resolve the question of the disputed line feature at 20-25 keV. During the first main flare the average luminosity increases by a factor of \~10, but the spectral shape remains very similar, except for a moderate softening.Comment: Accepted for proceedings of 5th INTEGRAL Worksho

Features of the porous morphology of anodic alumina films at the initial stage of disordered growth

A characteristic feature of disordered porous anodic film growth at the initial stage of aluminum anodizing was revealed by varying the electrolyte type and anodizing voltage. The samples were obtained by the electrochemical oxidation of thin aluminum films (100 nm thick) on SiO2/Si substrates in a 0.3 M oxalic acid at 10–50 V and were studied by SEM. The ImageJ analysis of the images revealed the simultaneous development of two large groups of pores: major pores with a large diameter and minor pores with a smaller diameter. When anodizing in oxalic acid at 10–50 V, it has been shown that the ratio of the diameters of the major and minor pores remains constant and is about 1.17. Using a geometric model, we demonstrated that the centers of the minor pores are located inside the elementary hexagonal cell formed by the centers of the major pores. Moreover, our results are very close to the theoretical value of 2/√3. At the initial stage of disordered pore growth, the development of minor pores rather than major pores is not a random process and is determined by energy-efficient conditions for the development of pores inside the hexagonal cells formed by the major pores. The increase in compressive mechanical stress in the anodic film leads to an interruption in the development of such pores

Multi-wavelength observations of the binary system PSR B1259-63/LS 2883 around the 2010-2011 periastron passage

We report on broad multi-wavelength observations of the 2010-2011 periastron passage of the gamma-ray loud binary system PSR B1259-63. High resolution interferometric radio observations establish extended radio emission trailing the position of the pulsar. Observations with the Fermi Gamma-ray Space Telescope reveal GeV gamma-ray flaring activity of the system, reaching the spin-down luminosity of the pulsar, around 30 days after periastron. There are no clear signatures of variability at radio, X-ray and TeV energies at the time of the GeV flare. Variability around periastron in the H$\alpha$ emission line, can be interpreted as the gravitational interaction between the pulsar and the circumstellar disk. The equivalent width of the H$\alpha$ grows from a few days before periastron until a few days later, and decreases again between 18 and 46 days after periastron. In near infrared we observe the similar decrease of the equivalent width of Br$\gamma$ line between the 40th and 117th day after the periastron. For the idealized disk, the variability of the H$\alpha$ line represents the variability of the mass and size of the disk. We discuss possible physical relations between the state of the disk and GeV emission under assumption that GeV flare is directly related to the decrease of the disk size.Comment: accepted to MNRA

Effect of anodic oxygen evolution on cell morphology of sulfuric acid anodic alumina films

The purpose of this work was to study and analyze the effect of electrolyte temperature and anodization voltage on cell morphology of thin films of sulfuric acid anodic alumina formed on substrates of different nature, such as SiO2/Si, glass-ceramic, glass substrates, and polished aluminum. The data obtained demonstrated that the thermal conductivity of the substrate in the voltage range from 12 to 14 V affected a pore diameter (dpore) in anodic films. Depending on the substrate type, dpore increased in the following order: glass > glass- ceramic > SiO2/Si > aluminum. It was found that the anodizing voltage (Ua) of 16 V was a turning point for anodic films obtained in sulfuric acid after which the slope of the lines for both dpore and Dinter (interpore distance) vs. Ua changed. This behavior might be explained by the occurrence of the overpotential enough for the beginning of the oxygen evolution reaction. We assumed that the oxygen evolution on aluminum oxide surface at the pore bottom at Ua> 16 V results in an increase in acid concentration in the solution and, consequently, in rise in acidic nature of the electrolyte and increase in the dissolution rate of the oxide layer of pore walls

Влияние селанка на морфин-индуцированную анальгезию в опытах in vivo

   Background. The endogenous opioid system is involved in neuroadaptation produced by exogenous opioids. Synthesized on the basis of the regulatory peptide tuftsin, the anxiolytic selank inhibits the activity of enkephalin-degrading enzymes, increasing the level of leu-enkephalins in blood plasma.   The aim of the work was to evaluate the effect of selank (0,3 and 0,9 mg/kg, i. p.) on morphine-induced analgesia in animal models. Methods. The experiments were performed in inbred male mice C57Bl/6 (n = 77). The “hot plate” test was used to evaluate the analgesic effect during thermal stimulation of nociceptors when mice were placed on a metal plate heated to 55 ± 0,5 °C, followed by registration of the latent period of the reaction 30, 60, 90, and 120 minutes after the administration of morphine.   Results. Morphine at a dose of 3,0 mg/kg, i. p., caused antinociception with the maximum possible effect (MBE) of 9 %, selank at a dose of 0,9 mg/kg, without antinociception per se, when pretreated with the morphine, increased the latent reaction time, causing antinociception of 29,9 % MBE.   Conclusion. For the first time the data obtained on the synergistic effect of selank and morphine in attenuation of acute somatic pain.   Актуальность. Эндогенная опиоидная система вовлечена в процессы нейроадаптации при действии экзогенных опиоидов. Синтезированный на основе регуляторного пептида тафтсина анксиолитик селанк угнетает активность энкефалин-деградирующих ферментов, повышая содержание лей-энкефалинов в плазме крови.   Цель работы. Оценить влияние селанка (0,3 и 0,9 мг/кг, в/б) на морфин-индуцированную анальгезию в опытах in vivo.   Методы. Эксперименты выполнены на инбредных мышах-самцах линии С57Bl/6 (n = 77). Тест «горячая пластина» использовали для оценки анальгетического действия препаратов при термической стимуляции ноцицепторов при помещении мышей на нагретую до 55 ± 0,5 °С металлическую пластину с последующей регистрацией латентного периода реакции через 30, 60, 90 и 120 мин после введения морфина.   Результаты. Морфин в дозе 3,0 мг/кг, в/б, вызывал антиноцицепцию с максимально возможным эффектом (MВЭ) 9 %, селанк в дозе 0,9 мг/кг, не обладая антиноцицептивными свойствами per se, при предварительном введении с морфином увеличивал латентный период реакции, вызывая антиноцицепцию с МВЭ 29,9 %.   Заключение. Впервые получены данные о синергическом эффекте селанка и морфина в ослаблении острой соматической боли

Stored charge and its influence on properties of anodic alumina films

In porous and barrier-type anodic alumina films, the stored charge has electronic nature and it plays a significant role in the process of aluminum anodizing. The charge stored can modify the distribution of local field generated by a voltage applied and thus it can affect the oxide growth. The method for the investigation of thermally activated defects in anodic alumina films by reanodizing technique was also described. It was applied for computation of activation energy of electron traps in barrier layer for sulfuric and oxalic acid alumina films and concentration of the traps

2003--2005 INTEGRAL and XMM-Newton observations of 3C 273

The aim of this paper is to study the evolution of the broadband spectrum of one of the brightest and nearest quasars 3C 273. We analyze the data obtained during quasi-simultaneous INTEGRAL and XMM monitoring of the blazar 3C 273 in 2003--2005 in the UV, X-ray and soft gamma-ray bands and study the results in the context of the long-term evolution of the source. The 0.2-100 keV spectrum of the source is well fitted by a combination of a soft cut-off power law and a hard power law. No improvement of the fit is achieved if one replaces the soft cut-off power law by either a blackbody, or a disk reflection model. During the observation period the source has reached the historically softest state in the hard X-ray domain with a photon index $\Gamma=1.82\pm 0.01$. Comparing our data with available archived X-ray data from previous years, we find a secular evolution of the source toward softer X-ray emission (the photon index has increased by $\Delta\Gamma\simeq 0.3-0.4$ over the last thirty years). We argue that existing theoretical models have to be significantly modified to account for the observed spectral evolution of the source.Comment: 11 pages, accepted to A&

Scientific Performance of the ISDC Quick Look Analysis

The INTEGRAL Science Data Centre (ISDC) routinely monitors the Near Real Time data (NRT) from the INTEGRAL satellite. A first scientific analysis is made in order to check for the detection of new, transient or highly variable sources in the data. Of primary importance for this work is the Interactive Quick Look Analysis (IQLA), which produces JEM-X and ISGRI images and monitors them for interesting astrophysical eventsComment: 4 pages, 3 figures. Proceedings of 5th INTEGRAL Workshop: The INTEGRAL Universe, Munich, 16-20 February 2004. Accepted for publication in European Space Agency Special Publication 552. See paper for institute affiliation

Study of microstructure of porous anodic alumina films formed in malonic acid in the wide range of aluminium anodizing voltages

In present paper the microstructure parameters of porous anodic alumina films formed by the anodizing of aluminum in the aqueous solution of malonic acid at different anodizing voltages was studied. The morphology of structured surface of aluminum film was studied using a scanning electron microscope after selective removal of anodic film. The results obtained for anodic films formed in malonic acid during anodizing in the range of 15-80 V allowed to determine that change in the interpore distance with the anodizing voltage is linear function with a slope of 1.45. The key conclusion was made that mechanical stress in anodic alumina layer is the main factor responsible for formation of the nanoporous structure of anodic alumina films

Monitoring of Electrode Temperature in Exothermic Electrochemical Process

In this paper the features of temperature control of aluminum electrode during the anodization are discussed. Temperature monitoring in this exothermic process is a necessary condition for obtaining a high ordered nanoporous structure. A new electrochemical cell with a Peltier device working in cooling or heating mode was proposed. Time dependences of the electrolyte and Peltier element temperatures without and during anodizing process were presented. The results demonstrated that the cell construction allows precise control of the electrode temperature