Now showing items 1-10 of 19
OJ 287 and 3C 279
Reaction-mechanisms for astrophysically relevant nuckear processes
The different reaction mechanisms and models applied to nuclear reactions at thermonuclear energies are discussed. As an example we consider the reaction Li-8(alpha,n)B-11.
New 325 MHz observations of H II galaxies - The mechanisms that shape the unusual radio spectra
The B array of the VLA has observed a sample of seven H II galaxies at 325 and 1489 MHz; the radio continuum spectra thus obtained exhibit a wide variety of spectral shapes, but four show a significant flattening toward ...
Excited hydrogen and the formation of molecular-hydrogen via associative ionization. 1 : Physical processes and outflows from young stellar objects
Rates for the associative ionization reaction H(n=2)+H→H2++e- are calculated. This reaction is found to be a greater contributor to the H2 formation rate than the direct radiative association reaction H(n=2)+H→H2+hν in ...
Convective overshooting and the observed width of the main-sequence band
(Astronomical Society of the Pacific, 1993)
For many years we are witnessing a lively debate on the existence and extent of convective overshooting, mainly in the cores of main-sequence stars. This is an important issue, since even a small amount of overshooting ...
The astrophysical S-factor of the reaction Be-7(P,gamma)B-8 in the direct capture model
The astrophysical S-factor for the reaction Be-7(p, gamma)B-8 up to an energy of 2 MeV (c.m.) and the capture cross section of Li-7(n, gamma)Li-8 up to 1 MeV (c.m.) are calculated using the Direct Capture model (DC). Both ...
An H I absorption survey of M31 and M33 - The mixture of warm and cool phases in the interstellar media of spiral galaxies
The VLA in A-array is used to survey the nearby spiral galaxies M31 and M33 in the 21-cm line in order to measure absorption by the H I toward background continuum sources. Spectral line cubes with rms noise less than 1.2 ...