Vol 44, No 6 (2018)

The sample of Byurakan–IRAS galaxies (BIG) has been created based on optical identifications of IRAS Point Source Catalog (PSC) at high galactic latitudes. As a result, 1178 galaxies have been identified. 172 of them have been observed spectroscopically with Byurakan Astrophysical Observatory (BAO, Armenia) 2.6 m, Special Astrophysical Observatory (SAO, Russia) 6m and Observatoire de Haute Provence (OHP, France) 1.93 m telescopes. Later on, spectra were obtained for more 83 BIG objects in Sloan Digital Sky Survey (SDSS). We have extracted and studied these spectra, classified them and measured spectral features. Diagnostic diagrams have been built to distinguish starbursts (SB), LINERs and Seyfert galaxies. Cross-correlations weremade for these objects with multiwavelength (MW) catalogues and their physical properties were studied. Among these 83 objects, 55 HII, 8 Seyfert galaxies, 2 LINERs, 4 other AGN, 6 composite spectrum objects, and 8 other emission-line galaxies have been revealed. Three of these objects are Ultra-Luminous InfraRed Galaxies (ULIRG).

We show that the Hα luminosity and the Thomson optical depth of supernova iPTF14hls on day 600 after its discovery make it possible to estimate the envelope age at this stage, which turns out to be ~1000 days. A model that suggests the explosion of a massive star with a radius of ~2 × 10¹³ cm 450 days before the discovery is proposed. In the optimal model the ejecta mass is 30 M_ʘ with a kinetic energy of 8 × 10⁵¹ erg. The energy source at the main luminosity stage is presumably associated with the relativistic bipolar outflows produced by disk accretion onto a black hole. The [O I] 6300, 6364 Å doublet in the spectrum on day 600 is shown to be the result of emission from at least 1–3M_ʘ of oxygen in the central ejecta zone. The oxygen distribution is aspherical and can be represented both by two blue- and redshifted components (in the optically thin case) and by one blueshifted component in the case of optically thick lines at an oxygen filling factor of ~2 × 10⁻³.

We analyze a long (with a total exposure time of 120 ks) X-ray observation of the unique Galactic microquasar SS 433 carried out by the XMM-Newton space observatory with the goal of searching for the fluorescent line of neutral (or weakly ionized) nickel at energy 7.5 keV. We consider two models for the formation of fluorescent lines in the spectrum of SS 433: (1) through the reflection of radiation from a putative central X-ray source off the optically thick neutral gas of the supercritical disk “funnel” walls; and (2) due to the scattering of the radiation coming from the hottest parts of the jets in the optically thin wind of the system. We show that for these two cases the flux of the Ni I K_α fluorescent line is expected to be 0.45 of the flux of the Fe I K_α fluorescent line at 6.4 keV for the relative nickel overabundance Z_Ni/Z = 10 observed in the jets of SS 433. For the continuum model without the absorption edge of neutral iron, we have found an upper limit on the flux of the narrow Ni I K_α fluorescent line of 0.9 × 10⁻⁵ phot s⁻¹ cm⁻² (90% confidence level). In the continuum model with the absorption edge we have determined an upper limit on the flux of the Ni I K_α line at the level of 2.5×10⁻⁵ phot s⁻¹ cm⁻². At the same time, the flux of the fluorescent iron line has been measured to be 9.9_8.4^11.2 × 10⁻⁵ phot s⁻¹ cm⁻². This result implies that the nickel overabundance in the accretion disk wind should be at least a factor of 1.5 times smal than the corresponding nickel overabundance observed in the jets of SS 433.