A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger.

Tidal disruption events (TDEs) are transient flares produced when a star is ripped apart by the gravitational field of a supermassive black hole (SMBH). We have observed a transient source in the western nucleus of the merging galaxy pair Arp 299 that radiated >1.5 × 1052 erg at infrared and radio wavelengths but was not luminous at optical or x-ray wavelengths. We interpret this as a TDE with much of its emission reradiated at infrared wavelengths by dust. Efficient reprocessing by dense gas and dust may explain the difference between theoretical predictions and observed luminosities of TDEs. The radio observations resolve an expanding and decelerating jet, probing the jet formation and evolution around a SMBH.

Hard-X-ray emission lines from the decay of 44Ti in the remnant of supernova 1987A.

It is assumed that the radioactive decay of (44)Ti powers the infrared, optical and ultraviolet emission of supernova remnants after the complete decay of (56)Co and (57)Co (the isotopes that dominated the energy balance during the first three to four years after the explosion) until the beginning of active interaction of the ejecta with the surrounding matter. Simulations show that the initial mass of (44)Ti synthesized in core-collapse supernovae is (0.02-2.5) × 10(-4) solar masses (M circled dot). Hard X-rays and γ-rays from the decay of this (44)Ti have been unambiguously observed from Cassiopeia A only, leading to the suggestion that values of the initial mass of (44)Ti near the upper bound of the predictions occur only in exceptional cases. For the remnant of supernova 1987A, an upper limit to the initial mass of (44)Ti of <10(-3) M circled dot has been obtained from direct X-ray observations, and an estimate of (1-2) × 10(-4) M circled dot has been made from infrared light curves and ultraviolet spectra by complex and model-dependent computations. Here we report observations of hard X-rays from the remnant of supernova 1987A in the narrow band containing two direct-escape lines of (44)Ti at 67.9 and 78.4 keV. The measured line fluxes imply that this decay provided sufficient energy to power the remnant at late times. We estimate that the initial mass of (44)Ti was (3.1 ± 0.8) × 10(-4), which is near the upper bound of theoretical predictions.

[Prognosis of inhalation-related injuries in accidental release of ammonium and chlorine by the method of dynamic concentration]. / Prognoz ingaliatsionnogo porazheniia cheloveka pri avariinom vybrose ammiaka i khlora metodom dinamicheskoi kontsentratsii.

The article deals with new approaches to evaluate casualty effect of accidental chemical release exemplified by common and dangerous industrial chemicals ammonium and chlorine. Dynamic concentration method considers effects of high concentrations inducing instant reflex cardiac and respiratory arrest as well as lesions caused by variable toxic doses.

[The effect of hydrodynamic conditions on the interferon-synthesizing activity of swine splenocytes in the production of alpha-interferon]. / Vliianie gidrodinamicheskikh uslovii na interferonsinteziruiushchuiu aktivnost' splenotsitov svinei pri poluchenii al'fa-interferona.

Parameters of physical constituents of the agitation process and mass-exchange characteristics of the suggested bioreactor for suspension cultivation of pig splenocytes are determined. The effect of hydrodynamic conditions on viability and interferon-synthesizing activity of cells in production of alpha-interferon of pigs has been studied. The relation existing between interferonogenesis processes proceeding under suspension and under stationary biosynthesis has been analyzed by the pair correlation method.

[The dynamics of the microorganism count of active sludge during the aerobic treatment of sewage]. / Dinamika chislennosti mikroorganizmov aktivnogo ila pri aérobnoi ochistke stochnykh vod.

Dynamics of the active sludge microorganism quantity is studied under different cultivation regimes. It is shown that quantity of microorganisms in different physiological groups depends on the specific growth rate, micro, determined by the dilution rate and biomass recirculation level. The results may be used for selecting optimal regime of the sewage treatment system functioning.