Identification of the interstellar cyanomethyl radical (CH2CN) in the molecular clouds TMC-1 and Sagittarius B2     

Irvine WM  Friberg P  Hjalmarson A  Ishikawa S  Kaifu N  Kawaguchi K  Madden SC  Matthews HE  Ohishi M  Saito S  Suzuki H  Thaddeus P  Turner BE  Yamamoto S  Ziurys LM 《The Astrophysical journal》1988,334(2):L107-L111

We report the astronomical identification of the cyanomethyl radical, CH2CN, the heaviest nonlinear molecular radical to be identified in interstellar clouds. The complex fine and hyperfine structures of the lowest rotational transitions at about 20.12 and 40.24 GHz are resolved in TMC-1, where the abundance appears to be about 5 x 10(-9) relative to that of H2. This is significantly greater than the observed abundance of CH3CN (methyl cyanide) in TMC-1. In Sgr B2 the hyperfine structure is blended in the higher frequency transitions at 40, 80, and 100 GHz, although the spin-rotation doubling is clearly evident. Preliminary searches in other sources indicate that the distribution of CH2CN is similar to that for such carbon chain species as HC3N or C4H.  相似文献   

Physical parameters of the Jovian atmosphere     

C. J. Banos  B. Petropoulos 《Earth, Moon, and Planets》1988,42(1):19-28

The following physical parameters have been computed for the Jovian atmosphere between 270 and ?300 km: (1) Pressure, (2) Density, (3) Speed and sound, (4) Number density, (5) Density scale. It has considered that the top of the clouds is at 0 km. For the calculations of these parameters we have used:

1. for the altitudes 270-0 km data from Voyager I and II.
2. for the altitudes ?300–0 km data from Voyager II and spectroscopic observations.

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BV centauri: dwarf or classical nova?     

J. W. Menzies  D. O'Donoghue  B. Warner 《Astrophysics and Space Science》1986,122(1):73-80

The similarity in properties of GK Per and BV Cen suggests that the latter may be a classical nova remnant rather than a dwarf nova. Our H and V CCD photometry show no sign of a nova shell but disclose the presence of a close and probably physical companion. BV(RI) _c CCD photometry of the companion, assumed to be a dwarf, givesM _v =3.1±0.3 for BV Cen at quiescence. Even though half of the light in BV Cen comes from the secondary this is much brighter than expected for a dwarf nova and supports the conclusion that BV Cen was an unrecorded nova.  相似文献   

Converging magnetogasdynamic cylindrical shock waves in a uniform atmosphere     

J. B. Singh  S. K. Mishra 《Astrophysics and Space Science》1986,127(2):361-369

A self-similar solution to the problem of the implosion of a cylindrical shock wave in the presence of a magnetic field has been investigated. A strong shock wave in a cylindrically-symmetric flow travels to the axis of symmetry through a gas of uniform initial density ₀ and zero-pressure. A comparative study has been made between the results obtained in ordinary gasdynamics and magnetogasdynamics with transverse and axial components of the magnetic field. The value of similarity exponent has been assigned from that found in the paper of Whitham (1958).  相似文献   

Is the International Atomic Time TAI a coordinate time or a proper time?     

B. Guinot 《Celestial Mechanics and Dynamical Astronomy》1986,38(2):155-161

The International Atomic Time TAI is a physically realized time scale which is ultimately used for comparisons between observations and dynamical theories. Its definition should tell unambiguously what an ideal TAI should be. For terrestrial applications, TAI has been defined as a geocentric coordinate time. In Solar System Dynamics, a barycentric coordinate time is needed. In general, it is not possible to convert a coordinate time into another coordinate time. But a specific clock synchronized on TAI in the terrestrial system can be considered as reading a modified, proper time [TAI]_i, which can be converted into a barycentric coordinate time. In this conversion appears a small location dependent term. By this process all the clocks of the TAI system give an unique barycentric time with the same metrological properties as TAI.

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Résumé Le Temps Atomique International TAI est une échelle de temps physiquement réalisée qui est utilisée pour la comparaison entre les observations et les théories dynamiques. Sa définition doit exprimer sans ambiguïté ce que devrait être un TAI idéal. Pour les applications terrestres, TAI a été défini comme un temps-coordonnée géocentrique. Pour la dynamique du système solaire, on a besoin d'un tempscoordonnée barycentrique. En général, il n'est pas possible de convertir un temps-coordonnée en un autre temps-coordonnée. Mais une horloge particulière synchronisée sur le TAI dans le système terrestre peut être considérée comme marquant un temps-propre modifié [TAI]_i: on peut alors convertir ce temps propre en un temps-coordonnée barycentrique. Dans cette conversion apparaît un terme petit dépendant de l'emplacement de l'horloge sur la Terre. Par ce procédé, toutes les horloges du système du TAI conduisent à un temps-coordonnée barycentrique unique qui bénéficie des mêmes propriété métrologiques que le TAI.

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An analysis of the spectrum of the zeta geminorum     

B. B. Sanwal  B. S. Rautela  G. C. Joshi 《Astrophysics and Space Science》1986,123(1):183-192

Four spectrograms of the cepheid Geminorum at different phases have been analysed for the determination of the abundances of various elements. The analysis shows that the atmosphere of Gem has an essentially solar composition.  相似文献   

Sunspot nests     

M. J. M Castenmiller  C. Zwaan  E. B. J. Van Der Zalm 《Solar physics》1986,105(2):237-255

For the period August 1959–December 1964 the Greenwich Photoheliographic Results were searched for sunspot nests. Such a nest is a sequence of sunspot groups that appear within a small area on the solar surface and that last for several months. The search procedure is described and data for 41 probable sunspot nests are given. At least three quarters of these nests appear to be real, and not chance clusters.The nests are the same type of activity sequences as the Fleckenherde discovered by Becker (1955) and the complexes of activity pointed out by Gaizauskas et al. (1983). The complexes of activity as defined by Bumba and Howard (1965) are different patterns, however; the relation between complexes and the nests is shown.Some properties of the nests are: (i) many nests appear as double structures; (ii) single nests and components of double nests are quite compact: the effective areas are comparable to those of medium-large sunspot groups; (iii) each nest rotates at its own steady rate about the Sun; (iv) the intrinsic scatter in the rotation rates is much larger than the trend in the differential rotation; (v) displacements in latitude are less than a few meters per second; (vi) many nests live for 6 to 15 Carrington rotation periods, the minimum lifetime is not yet determined; (vii) the fraction of the sunspot groups that are members of nests is large (at least 30%).  相似文献   

Energy interconnection between the plasma cloud ejected from the active region and the shock wave     

I. N. Garczyńska  B. Rompolt 《Solar physics》1986,105(1):101-109

The relation between the ejected plasma cloud and the shock wave propagating ahead of it is examined for 27 pairs of such events. The flare sprays and the eruptive prominences observed in H line as well as the fast-moving sources of type-IV radio bursts have been considered as such ejected plasma clouds. Propagation of the shock wave in the solar corona has been examined from the observations of type-II radio bursts. Using the Parker model of the propagation of a shock wave, the shock wave velocity has been compared with the plasma cloud velocity. Energy interconnection between these two events has been studied. In the majority of the investigated cases there exists an energetic interconnection between the plasma cloud and the shock wave.  相似文献   

Properties of r-modes in the Sun     

Charles L. Wolff  Jane B. Blizard 《Solar physics》1986,105(1):1-15

Global oscillations of the Sun (r-modes) with very long periods 1 month are reviewed and studied. Such modes would be trapped in an acoustic cavity formed either by most of the convective envelope or by most of the radiative interior. A turning point frequency giving cavity boundaries is defined and the run of eigenvalues for angular harmonics l 3 are plotted for a conventional solar convection zone. The r-modes show equipartition of oscillatory energy among shells which each contain one antinode in the radial dimension. Toroidal motion is dominant to at least the 14^th radial harmonic mode. Viscosity from convective turbulence is strong and would damp any mode in just a few solar rotations if it were the only significant nonadiabatic effect. Radial fine splitting which lifts the degeneracy in n is very small (20 nHz or less) for all n 14 trapped in the envelope. But, if splitting could be detected, we would have a valuable new constraint on solar convection theories.  相似文献   

The production of light elements in unconventional cosmologies with VMOs     

Yu. A. Shchekinov  B. V. Vainer 《Astrophysics and Space Science》1986,123(1):103-115

The abundances of light elements (deuterium, helium and lithium) are calculated in unconventional cosmologies in which these elements are produced by interaction of fast -particles ejected by massive pregalactic stars with a purely hydrogenous cosmological substrate. The number density and energetics of such stars needed for suitable production of light elements are estimated. It is shown that the models always lead to overproduction of lithium. The intensity of ultraviolet, X-ray, and -ray emission caused by explosions of pregalactic massive stars is calculated. The distortions of cosmic background radiation by Compton losses of electrons heated by explosive stars are also calculated.  相似文献