Том 63, № 11 (2019)

The spatial correlation between HII region and diffuse ionized gas found earlier for the Hα line is confirmed using radio observations. In the inner part of the Galaxy, in the direction with coordinates l = 30°, b = 0°, the ionizing radiation from HII regions can propagate to distances ⩽240 pc, although 75% of this ionizing radiation arrives at mean distances of only ⩽7 pc. At the Galactic anti-center (l = 186.°6, b = 0.°32), the ionizing radiation of HII regions is able to ionize gas to distances of ⩽ 1300 pc, although 66% of this radiation ionizes gas at distances of ⩽155 pc. The relationship between the distributions of HII regions and diffuse ionized gas is used to derive the parameters of this gas in the direction of the pulsar B1758-23: emission measure 5800 ± 900 pc/cm⁶, mean electron density in clouds 5.42 cm⁻³, extent of the region occupied by clouds 200 pc, and filling factor for the electrons 0.06. The maximum contribution to the emission measure, dispersion measure, and scattering parameters of B1758-23 are made by a region at a distance of ≈1.3 kpc from the observer. The distance to PSR B1758-23 is found to be 3.5(+1, −0.3) kpc.

Jets can be not only ultrarelativistic, but also relativistic but with velocities appreciably lower than the speed of light. They can be launched not only by supermassive black holes in active galactic nuclei, but also by young, rapidly rotating stars (Herbig-Haro objects) and microquasars, which are binary systems displaying supercritical accretion onto a black hole (e.g., the SS 433 system) [1]. It is believed that the mechanisms for the launching of jets in these systems are related. The polarization properties of weakly relativistic cylindrical jets in an inhomogeneous magnetic field are studied in the geometrical optics approximation for the cases of isotropic and anisotropic distribution functions for the radiating particles. Various configurations for a helical magnetic field satisfying the force-free approximation are considered. In addition, the PLUTO code is used to model a jet with an inhomogeneous magnetic field. The intensity, spectrum, and polarization of gyrosynchrotron radiation of the jets are computed.

The evolution of the parameters of the residual velocity ellipsoid of hot subdwarfs (HSDs) with their position relative to the Galactic plane is traced, using the HSDs selected by Geier et al. from the Gaia DR2 catalog. Parameters of the Galactic rotation are determined for two ∣z∣ zones. These are used to estimate the gradient of the circular rotation velocity, V₀, versus ∣z∣, found to be ΔV₀/Δ∣z∣ = −71 ± 7 kms⁻¹kpc⁻¹. The size of the residual velocity ellipsoid is (σ₁, σ₂, σ₃) = (36.1, 27.6, 22.8) ± (0.4, 0.8, 0.6) km/s for HSDs at ∣z∣ < 0.5 kpc and (σ₁, σ₂, σ₃) = (56.9, 55.8, 39.7) ± (0.9, 1.1, 0.8) km/s for HS Ds at ∣z∣≥ 0.5 kpc. When forming the HSD residual velocities, the Galactic rotation was taken into account using individual approaches for each z zone. Parameters of the residual velocity ellipsoids for HSDs located in four plane-parallel layers are also determined. The size of the ellipsoid increases with z, and the inclination of the first axis relative to the Galactic plane also increases. This inclination is close to zero in zones close to the Galactic plane, z ∼ ±0.2 kpc, and rises to ∓12° ± 4° for z ∼ ±0.9 kpc.

A new approach to the use of analytical computations of the linear polarization in the Hα line generated by fluxes of accelerated electrons during solar flares is presented. The model for the electron distribution function and the analytical expressions used for the excitation cross section and the degree of linear polarization are described. Test computations of the degree of linear polarization were carried out, and the dependence of the degree of linear polarization on the parameters of the electron distribution function in the solar chromosphere is analyzed. The possibility of applying this method to estimate the parameters of the anisotropic electron distribution corresponding to the measured polarization is demonstrated.

Finding several molecules having cyanide group (-C≡N) and isocyanide group (-N≡C), scientists searching for life in the universe, are interested in the molecules having two cyanide or isocyanide groups. Diisocyanomethane (CNCH₂NC) having two isocyano groups is an interesting candidate for the astronomers, though it has not been detected in any cosmic object. However, three organic isocyanides (HNC, CH₃NC, HCCNC) have been found in the interstellar medium (ISM). Submillimeter wave spectrum of CNCH₂NC is analyzed by spectroscopists, so that it could be searched in the ISM. For searching CNCH₂NC in a cosmic object, information about its strong spectral lines is essentially required. For that, in our investigation, the rotational levels of CNCH₂NC can be classified into two species. The energies of lower 250 rotational levels up to 108 cm⁻¹, in the ground vibrational state, and the radiative transition probabilities for rotational transitions in each species are calculated, using the values of rotational and centrifugal distortion constants along with the electric dipole moment. A set of statistical equilibrium equations coupled with the equations of radiative transfer is solved by using the radiative transition probabilities and the scaled values of collisional rate coefficients as input data. For each species, we have found two transitions showing emission feature and four transitions showing anomalous absorption. These 12 transitions may help in the detection of CNCH₂NC in a cosmic object.