Seyfert galaxies with linear nuclear radio structures have been studied with long-slit spectroscopy. Very extended, narrow [OIll] emission is detected in several of the objects, highly elongated along the radio source axis. This Extended Narrow Line Region would be consistent with interstellar gas that is photoionized by collimated energetic radiation from the nucleus. Within the Narrow Line Region detailed correspondences between [Olll] emission features and individual radio components have been found in a number of Seyfert galaxies. Velocities and positions of these [OIll] features suggest that they may be produced when ambient gas has been compressed by an outmoving radio component, subsequently cools down behind the bow shock and then is photoionized by the nuclear continuum source.
We develope a kinematic model based on a dynamical model of stellar population synthesis. We compare the model predictions with two proper motion catalogues.
Broad-band UBV light and color observations of KY And obtained in September 1982 at the Hvar Observatory have been analyzed. It was found that no single frequency satisfied the data well enough, hence, a multifrequency fit has been determined.
We present various observations of the bipolar nebula No. 14 from the list of Neckel and Staude (1984): CCD images at 7 different wavelengths, spectroscopy at intermediate resolution between 4800 A and 9500 A, and CCD stellar polarimetry. The centra! star turns out to be a "Trapezium" consisting of four stars of spectral types between B0.5 and A5. The nebular spectrum is that of a low
excited HII region, but in addition it exhibits a strong Ol 8446 line excited by Lyman β fluorescence. This requires a very high optical depth in Hα γ ≥ 1000) in the emitting region, which has been spatially resolved in NS 14. The stellar polarimetry, combined with the surface polarimetry of Scarrott et al. (1986), indicates that the polarization in the nebula can be explained by pure scattering
alone.
High resolution observations of the active region MacMath 16315 near the center of the disk were analysed in order to study the bright points, both below an Arch Filament system and in two neighbouring regions covered by plagettes. The average value of the relative intensity of the bright points with respect to the background in the plagette regions as well as under the Arch Filament system was 1.13 t 0.033. This value was the same for
Hα-1.0 A as well as for Hα-0.75 A . The lifetime of bright points under the Arch Filament System ranges from 3 to 18 min with
average value of 10 min. The time evolution of the intensity of bright points under the Arch Filament system is different from that of the Ellerman bombs under the same system f. The relative intensity of bright points rises to the maximum value within 1 min and remains constant during the rest of its lifetime. The average size of bright
points at Hα-1.0 A was found smaller than that at Hα-0.75 A.
The presented catalogue contains a list of all chromospheric flares of importance 2+, 3, and 3+, observed during the years 1859-1956, together with ionospheric disturbances, geomagnetic storms and aurorae possibly connected with them. All papers discussing problems connected with these flares and their geophysical consequences are summarized in the index of literature.
Over the last decade, extensive observations of carbon monoxide emission in the disk of our Galaxy have shown that molecular (H2) gas rather than atomlc (HI) hydrogen is the major actlve component of the interstellar medium. In the Galaxy, virtually all known regions of star formation activity are associated with molecular clouds. In this artlcle, we review the theoretical and empirical basis for using the 2.6 mm CO emission line as a tracer of H2 and summarize the galactic distribution and properties of the molecular clouds.
Molecular clouds are the dominant component of the interstellar medium in the inner half of the galactic disk at R <0.8 R . Most of the molecular gas is in clouds at the hlgh end of the mass spectrum with mass >10^5 (GMC), with over half the mass in clouds with M >4 x 10^5 M^. The longitude and velocity of 'warm' molecular clouds, whose temperatures imply substantial internal heating, are correlated with giant HII regions and may be associated with armlike spiral structure. Cooler clouds are distributed much more widely throughout the disk. The radial distribution of cloud
nuraber denslty is similar to the distribution of CO emlssivity - that is, a ringlike concentratlon at 0.4 - 0.8 Rq with a relatlvely sharp inner edge and a gradual falloff toward large R. Giant molecular clouds do not fit Into a two- or three-phase pressure-equlllbrlum plcture of interstellar matter. They are gravitationally bound and their Internal pressure, domlnated by chaotic raotions, is 2 orders of magnitude greater than the standard Interstellar medium pressure.
A likely orlgin for these clouds is gravitational Instability.
The missing daily relative sunspot numbers in the time interval 1818-1848 were reconstructed by the nonlinear two-step method of interpolation. In the first step directly interpolated gaps were not longer than five days. In the second step, the data were sorted in the so called Bartels scheme, i.e. in rows of the length of 27 days
subsequently ranged in a matrix. The missing data of longer gaps were interpolated columnwise, i.e. the missing value at any position was interpolated from the data at the same positions of preceeding and following rows. The procedure enables to interpolate long gaps and simultaneously respect the 27-day data variation. The Appendix A contains annual tables of daily data, Appendix B gives monthly and annual means and Appendix C presents simutaneously annual plots of primary data and of those reconstructed by interpolation. The differences between the monthly and annual means of primary data and of data completed by interpolation are small and fluctuate around zero. Only in the time interval 1835-1842, when the frequency of observations was lowered, the amplitude of fluctuations is enhanced. The dispersion of monthly differences σ is ±4.3 R and of annual means ±1,1 R. The two-step method of interpolation was tested on the daily data series in the time interval 1918-1948. The sequence of missing daily data in the years 1818-1848 represents a masking function. The differences between the monthly and annual means of primary and modified data are small with fluctuations around zero and with dispersion σ for monthly differences ±2.7 R and for annual differences ±0.6 R. The small dispersion gives evidence about a high reliability of relative sunspot numbers derived from observations in the years
1818-1848 and also about the effectivity of the two-step method of interpolation. and Materiál obsahuje 3 (nestránkované) apendixy:
- Appendix A Daily relative sunspot numbers 1818-1848 [s. 6-22]
- Appendix B Monthly and annual means of relative sunsppot numbers 1818-1848 [s. 23-24]
- Appendix C Plots of daily relative sunspot numbers 1818-1848
[s. 25-56]