The neutral hydrogen emission at 21 cm has been investigated with the RATAN-600 radio telescope in the vicinity of the supernova remnant HB9. A clumpyHI shell with radial motions surrounding the remnant has been detected. Its measured parameters contradict the connection with a shock wave from a supernova explosion. The shell formation under the action of a wind from a star that exploded as a supernova at the end of its evolution seems more realistic. The characteristics of the star obtained from the observed shell parameters are the following: a wind power of 0.5 × 1038 erg s−1, a mass-loss rate of 3.7 × 10−5 M ⊙ yr−1, and an age of 3 × 106 yr. Given the measurement errors, the mass of the star is estimated to be >8M ⊙.

1932 into the family of a well-known scientist, geophysicist and astronomer Nikolai Nikolaevich Pariiskii, Corresponding Member of the USSR Academy of Sciences, and Lidiya Viktorovna Pariiskaya, who for a long time worked in the Theory Department of Lebedev Physical Institute (FIAN) in close contact with Andrei D Sakharov. There were close ties of friendship betweenPariiskii's family and those of I ETamm and M A Leontovich (they were next-door neighbors in their country houses, organized joint country walks, enjoyed evening parties with charades for entertainment). Such a close relationship with brilliant personalities helped Yurii Nikolaevich formulate the fundamental principles that would guide him in life and shape his attitude toward science. YuN graduated from Moscow State University in 1955 majoring in astronomy (he was also a student of the Moscow Institute of Mechanics in 1950±1951, and of the Moscow Electrotechnical Institute of Communications in 1951±1952). Among his teachers we should single out I S Shklovskii, who immensely influenced his young students and who in 1953 pioneered radio astronomy lectures to third-year students of the university. N S Kardashev, V G Kurt, and N S Soboleva, who later became prominent astronomers, were in the same student class with YuN. When doing his graduation thesis at FIAN inMALeontovich's department underAESalomonovich's supervision, in 1954 he built, on his own, a radiometer for the observation of the solar eclipse at the wavelength of 8 mm (Novomoskovsk), and used the results of his observations for getting more accurate data on the structure of the solar chromosphere. After graduation from the university, he was assigned a position at the Main Astronomical Observatory at Pulkovo (Leningrad) and there joined the just organized Department of Radio Astronomy, which was headed at the time by S E Khaikin, the founder of experimental radio astronomy in the USSR. Yurii Nikolaevich's entire subsequent career in science developed in both creative and family union with Nataliya Sergeevna Soboleva. S E Khaikin suggested that Yu N Pariiskii start highresolution studies of continuously emitting radio sources in the centimeter wave range (resolution of 1 arcminute at a wavelength of 3 cm) using a novel VPA (variable profile antenna) type radio telescope Ð the Large Pulkovo Radio Telescope (BPR in Russ. abbr.), where observations first began in December 1956. This work required high-sensitivity radiometers. Since this radio telescope is a transit instrument, a generation of high-sensitivity broadband radiometers with traveling-wave tube amplifiers at the wavelengths of 8 mm, 3.2 cm, and 6 cm were built, in contrast to designs of telescopes abroad based on narrow-band radar radiometers; Yurii Nikolaevich took a very active part in the work of building these devices. The first test of the new high-sensitivity radiometers mounted on the BPR made it possible to carry out highresolution observations: it therefore became possible to test the hypothetical explanation of the heating of certain details (discovered on the Sun by astronomers brought up by the Pulkovo scientific school of radio astronomy) in terms of micropulsations of magnetized plasma over solar spots; some theoretical groups were working on the theory of these pulsations. The reality of this phenomenon was not confirmed, which limited the number of possible theories. As a result, an alternative model of magnetized plasma in such very hot `bags' above sunspots was developed (together with N S Soboleva and D V Korolkov). The very first high-resolution survey of the Milky Way (1961) gave interesting results. For example, the fine structure of a radio source less than 1 arcmin in size was found at the center of the Galaxy. This work was presented at international symposia and caused great interestÐand not only in the scientific world. Journalists were writing at the time that Yu N Pariiskii discovered a `blazing bonfire' at the center of our galaxy. Uspekhi Fizicheskikh Nauk 182 (8) 901 ± 902 (2012) DOI: 10.3367/UFNr.0182.201208l.0901 Translated by V I Kisin PERSONALIA PACS number: 01.60.+q

The neutral hydrogen at 21 cm has been investigated with the RATAN-600 radio telescope around the supernova remnant G 65.3+5.7, which has the largest angular sizes in the group of shell remnants. An expanding HI shell left after an old supernova explosion with an energy of ∼10 51 erg and an age of 440 000 yr coincident in coordinates with the radio and optical remnant has been discovered. Since an X-ray emission from a much younger (27 000 yr) supernova remnant is observed in the same region and the shells detected by nebular lines have probably intermediate ages, we suggest that several successive supernova explosions have occurred here.

We study a compact group of 18 galaxies in the cluster A1367 with redshifts z = 0.0208–0.025. The group’s center of activity in the radio is the galaxy NGC 3862, whose radio flux is an order of magnitude stronger than for the other members of the group. We present coordinates derived from the Palomar plate archive together with recessional velocities, and analyze other characteristics of the group’s galaxies. The results of 1400 MHz observations of NGC 3862 with the RATAN-600 radio telescope are presented. These observations indicate that the galaxy’s radio emission is variable.

The well-known shell supernova remnant (SNR) HB3 is part of a feature-rich star-forming region together with the nebulae W3, W4, and W5. We study the HI structure around this SNR using five RATAN-600 drift curves obtained at a wavelength of 21 cm with an angular resolution of 2′ in one coordinate over the radial-velocity range −183 to +60 km s−1 in a wider region of the sky and with a higher sensitivity than in previous works by other authors. The spatial-kinematic distribution of HI features around the SNR clearly shows two concentric expanding shells of gas that surround the SNR and coincide with it in all three coordinates (α, δ, and V). The outer shell has a radius of 133 pc, a thickness of 24 pc, and an expansion velocity of 48 km s−1. The mass of the gas in it is ≈2.3 × 105M⊙. For the inner shell, these parameters are 78 pc, 36 pc, 24 km s− 1, and 0.9 × 105M⊙, respectively. The inner shell is immediately adjacent to the SNR. Assuming that the outer shell was produced by the stellar wind and the inner shell arose from the shock wave of the SNR proper, we estimated the age of the outer shell, ≈1.7 × 106 yr, and the mechanical luminosity of the stellar wind, 1.5 × 1038 erg s−1. The inner shell has an age of ≈106 yr and corresponds to a total supernova explosion energy of ≈1052 erg.

We analyze the angular structure of the 21-cm interstellar neutral hydrogen emission at six and seven declinations in the northern (published previously) and southern polar caps of the Galaxy (Galactic latitudes from −40° to −90°), respectively, with an extent of 90° in right ascension. The RATAN-600 radio telescope has a beam width averaged over these regions of 2.′0×30′. One-dimensional power spectra for the angular distribution of interstellar neutral hydrogen emission were computed in each 6.3-km s−1-wide spectral channel by using the standard Fast Fourier Transform (FFT) code and were smoothed over 1h in right ascension. The Galactic latitude dependence of the mean parameters for the sky distribution of H I line emission at high latitudes was found to correspond to the distribution of gas in the form of a flat layer only in the northern region, while in the southern cap, the gas distribution is much less regular. In addition, the mean H I radial velocities are negative everywhere (−3.7±3.0 km s−1 in the north and −6.0±2.4 km s−1 in the south). The power spectra of the angular fluctuations in the range of angular periods from 10′ to 6° appear as power laws. However, the spectral indices change greatly over the sky: from −3 to −1.2; on average, as the Galactic latitude increases and the H I column density decreases, the fluctuation spectrum of the interstellar gas emission becomes flatter. In the northern polar region, this behavior is much more pronounced, which probably stems from the fact that the gas column density in the south is generally a factor of 2 or 3 higher than that in the north. Therefore, the spectra are, on average, also steeper in the south, but the dependence on Galactic latitude is weaker. Using simulations, we show that the observed power-law spectrum of the H I emission distribution can be obtained in terms of not only a turbulent, but also a cloud model of interstellar gas if we use our previous spectra of the diameters and masses of H I clouds.

The HI distribution in the region of the radio source Cygnus X and the supernova remnant G78.2+2.1 has been investigated using observations in the 21-cm radio line with an angular resolution of 2.4' obtained on the RATAN-600 radio telescope. Two HI shells can be distinguished: the first (diameter approximate to 7 degrees) surrounds the entire extended thermal radio source Cygnus X, while the second, smaller, one (diameter approximate to 2 degrees) envelops the supernova remnant. Both shells display expansion with velocities exceeding 10 km/s. To compare the HI and ionized-gas velocities, the region was observed in the H-alpha line with a Fabry-Perot interferometer and CCD array on the 125-cm telescope of the Crimean Laboratory of the Sternberg Astronomical Institute. The molecular-gas distribution around Cygnus X is considered on the basis of the CO line emission. The physical parameters of HI shells are determined, and their nature is discussed. The presence of a large HI shell and a cavity in the molecular-gas distribution around Cygnus X indicates that the radio source may form a single structure. The smaller HI shell around G78.2+2.1 could have been created by either the supernova explosion or the stellar wind of the precursor star.

The angular structure of the interstellar neutral-hydrogen emission at 21 cm is studied at declinations of +5 degrees, +16 degrees, +25.7 degrees, +39 degrees, and +50 degrees in the range of right ascensions 10(h) to 16(h) (at Galactic latitudes from +45 degrees to +90 degrees) using the RATAN-600 radio telescope with a mean beamwidth of 2.0' x 20'. The frequency resolution is 30 kHz (6.3 km s(-1)), and the rms noise fluctuations are 0.1 K. The large-scale structure of the gas at high latitudes is eliminated by means of a high-pass filter. The angular-frequency spectrum of the interstellar neutral-hydrogen emission is calculated in each spectral channel by using the standard FFT software and smoothed over 1(h) in right ascension. The Galactic-latitude dependence of the mean parameters for the distribution of H I line emission over the sky (the H I column density and the dispersion of fluctuations in antenna temperature) is found to generally correspond to the gas distribution as a plane layer. In the region 11(h) < a < 13(h) and 27 degrees < delta < 39 degrees, the gas column density is lower than 1.5 x 10(19) cm(-2), i.e., below the instrumental sensitivity level. The power spectrum of the angular fluctuations in the region studied in the range of angular periods 10' to 6 degrees is a power-law spectrum with an exponent from -3 to -0.7; in general, as the H I column density decreases, the fluctuation spectrum of the interstellar-gas emission becomes flatter.

The diameters, masses, and velocity dispersions of internal motions of 7600 neutral-hydrogen clouds were determined from the results of a RATAN-600 HI Survey in Galactic-longitude quadrants II and III (180 degrees < l < 260 degrees, -15 degrees < b < +15 degrees and 100 degrees < l < 150 degrees, -10 degrees < b < +10 degrees). The linear diameters of the clouds are, on average, a factor of 2.5 larger along the Galactic plane than perpendicular to it. A relation between the HI density in the clouds and their diameters in the form n(H) proportional to d(-1.25 +/- 0.01) is confirmed (the correlation coefficient between logn(H) and logd is -0.87), and is probably free of selection effects. Another important relation-between the velocity dispersion of the internal gas motions in the clouds and their diameters, detected for the population of molecular clouds-is absent in the HI clouds; this may testify to a negligible role for internal turbulence in the clouds of neutral gas. Thirty-six percent of the HI clouds have systematic radial-velocity gradients across their disks, which are characteristic of; rotational motion. The presence of rotation in the HI clouds may explain the comparatively large widths of their emission-line profiles. The mean angular velocity of rotation of the clouds is of the order of 10(-13) rad s(-1), and dme mean energy of the rotational motion is 10(48) erg, which is comparable to the energy of random motion of the clouds. Finally, the number of clouds observed to have opposite directions of rotation is the same to within 5% in both Galactic-longitude quadrants.

HI observations with the RATAN-600 radio telescope have confirmed the presence of a ring structure of neutral hydrogen in the region of Cyg OB 1, at least at positive velocities, and revealed no traces of radial gas motions in this association. In the region of the radio source Cygnus X and the Cyg OB2 association, the HI distribution has been found to be related to the huge shell previously detected by H-alpha filaments and to the distribution of ionized gas as derived from recombination lines.

Measurements of the spectrum of Jupiter and the radio source Sgr B2 in the 1404.49-MHz line for the superfine transition (G'G'-GF) = 3/2, 5/2-1/2, 3/2 of the molecular ion H-2(+) are observed at the 4 sigma level. Various models that could lead to a significant abundance of H-2(+) are discussed. Expected brightness temperatures are estimated.

The results of a complex program of research on the extended infrared shell around the nebula NGC 6888 and the star WR 136 are presented. We performed H-alpha observations with a Fabry-Perot interferometer mounted at the focus of the 125-cm telescope and radio continuum (2.7 to 31 cm) and 21-cm H I observations with the RATAN-BOO radio telescope. A thick expanding shell of neutral hydrogen 120 pc in diameter that immediately surrounds the extended infrared shell was detected. This suggests that the infrared shell is a single structure rather than a chance projection of physically unrelated objects. The radial velocity of the H I shell is 11 +/- 1 km s(-1), the expansion velocity is 10 +/- 3 km s(-1), and the mass of the neutral hydrogen in the shell is 10(4)M(.). The bright radio features that we detected in the region of the infrared shell all exhibit a flat spectrum typical of thermal emission from optically thin H II regions, The same inference is probably also true for the nebula Simeiz 55. Our observations are consistent with the assumption of A,P. Marston that the extended shell was formed by the stellar wind from the precursor of WR 136, but they do not rule out the identification with a very old supernova remnant proposed by J. Nichols-Bohlin and R.A. Fesen, either. A revision of the distance to the pulsar PSR J2013+3845 with inhomogeneity of the interstellar medium taken into account allows for its formation during the same supernova explosion some 4 x 10(5) years ago.

The structure of the OH absorption feature in the sources W 44 and W 51 at 1665 and 1667 MHz was studied with a resolution of 2' x 110' x 5.5 km g-1 using the RATAN-600 radio telescope. The effective area of the antenna is 1000 m2; the standard deviation on the recordings is 0.15 K in brightness temperature. Parameters of OH absorbing clouds were determined, and these were compared with HI absorbing clouds.

We report the results of a search for the 1346.8-MHZ HCN line in the infrared star IRC + 10216. This line arises in transitions between the 1-doubling components of the J = 2 level (0,1(1),0) vibrational system. The observations were carried out in May 1990 and May 1991 using the RATAN-600 radio telescope. No line emission was detected above 1 00 mJy at the 2sigma level.