卷 101, 编号 8 (2024)

Present survey is a continuation of our research of high mass star forming regions in the lines of deuterated molecules, the first results of which were published in [1]. This paper presents the results of observations of 50 objects in the line of ortho modification of singly deuterated ammonia NH ₂ D $1_{11}^s-1_{01}^a$ at frequency 85.9 GHz, carried out with the 20-m radio telescope of the Onsala Space Observatory (Sweden). This line is detected in 29 sources. The analysis of obtained data, as well as the fact that gas density in the investigated sources, according to independent estimates, is significantly lower than the critical density for this NH ₂ D transition, indicate non-LTE excitation of NH ₂ D. Based on non-LTE modeling estimates of the relative content of the NH ₂ D molecule and the degree of deuterium enrichment were obtained, and the dependencies of these parameters on temperature and velocity dispersion were analyzed with and without taking into account detection limits assuming the same gas density in all sources. An anticorrelation between the NH ₂ D relative abundances and the kinetic temperature is revealed in the temperature range 15–50 K. At the same time, significant decrease in the ratio of the NH ₂ D/NH ₃ abundances with increasing temperature, predicted by the available chemical models, is not observed under the adopted assumptions. An anti-correlation was also revealed between the relative content of the main isotopologue of ammonia NH ₃ and the velocity dispersion, while no statistically significant correlation with the kinetic temperature of sources in the same temperature range was found.

Ultra-hot Jupiter Kelt9b impels to reconsider existing models of the upper atmospheres of hot exoplanets, which were previously developed using the example of G or M star systems such as HD209458b and GJ436b. The unique conditions of interaction between the radiation of an A-class star and the atmosphere necessitate kinetic modeling of excited levels of elements, primarily the hydrogen atom. For Kelt9b, the absorption was measures for several Balmer lines and lines of a number of heavy elements, the quantitative interpretation of which is an urgent task. In this work, for the first time, 3D modeling of the atmosphere of a planet with a close location of the Roche lobe has been implemented, taking into account the aeronomy and kinetics of excited hydrogen.

The analysis of variations in the radiation intensity of the pulsar B0950+08 from 2014 to 2022 with scales from minutes to years was carried out. The observations were obtained in a round-the-clock daily survey conducted on the Large Phased Array (LPA) radio telescope. The high variability of radiation is shown not only from pulse to pulse, but also at scales greater than 3 min. The average value of the estimated amplitude of these variations in 3.2 minutes is 25 Jy, the modulation index is 1. The average relative amplitude of the interpulse (IP) is 2.00 ± 0.28 % of the main pulse. In individual pulses, the amplitude of the interpulse may exceed the amplitude of the main pulse (MP), but this is a rare event. Radiation is observed in almost the entire period of the pulsar. For the first time, the relative amplitude of radiation between the main pulse and the interpulse (radiation bridge) was measured. When averaging about 10 hours, it varies from 0.8% to 1.31% with an average value of 1.04 ± 0.28 %. A high correlation was found between MP and IP amplitude variations both when averaging profiles over 3.2 minutes and when averaging over years. This correlation is due to refractive interstellar scintillation. The frequency scale of IP diffraction interstellar scintillation was measured for the first time and it was shown that the spectral forms for IP and MP are well correlated and have the same frequency scale. There are strong variations in the frequency scale of scintillation f _dif from session to session (time interval from one day) on scales of 200–800 kHz. The refractive scale of scintillation for 1–2 days has been determined. A modulation of radiation with a characteristic scale of about 130 days was detected, which, apparently, is also associated with refractive scintillation.

Nitric oxide is a potential biomarker in the N ₂ -O ₂ atmospheres of terrestrial exoplanets, which can be detected by space missions, including the planned launch of the Russian Spektr-UF observatory. From observations of the Earth's thermosphere in the polar regions, it is known that important sources of formation of this molecule are the precipitation of high-energy electrons into the planet's atmosphere, as well as the non-thermal processes accompanying them. In this paper the non-thermal processes of nitrogen oxide formation in the polar regions of the Earth's upper atmosphere are investigated, as well as the atmospheres of exoplanets located in the potential habitability zone of active stars. For this purpose, a numerical kinetic Monte Carlo model of the interaction of high-energy electrons with atmospheric gas has been developed; a kinetic Monte Carlo model of the interaction of suprathermal N( ⁴ S) atoms formed as a result of dissociation of N ₂ molecules by electron impact with the surrounding gas; as well as a model of odd nitrogen chemistry with taking into account the molecular and turbulent diffusion. According to the results of calculations, it is confirmed that the process of dissociation of N ₂ by an electron impact during the interaction of the stellar wind with the atmosphere of the planet is an important source of suprathermal N atoms, which contribute to a significant increase in the non-thermal formation of NO in the N ₂ -O ₂ atmospheres of terrestrial planets (both locally, in the case of a planet's own magnetic field, and throughout the planet's surface, in the case of its absence). Because the column concentration of NO during flares becomes larger, therefore the chances of detecting of nitric oxide biomarker in the atmospheres of the terrestrial-type exoplanets located in the potential habitability zone of active stars are also become larger.