Astrophysics
A lunar occultation event of the Wolf-Rayet star WR 112 (type WC9) has been observed simultaneously from two independent telescopes at lambda = 2.2microns, allowing us to investigate this source with an angular resolution of approx 0.003…
AGILE is an innovative, cost-effective gamma-ray mission proposed to the ASI Program of Small Scientific Missions. It is planned to detect gamma-rays in the 30 MeV - 50 GeV energy band and operate as an {\bf Observatory} open to the…
In this study we compute the structure and evolution of carbon-oxygen DA white dwarfs by means of a detailed and updated evolutionary code. We treat the energy transport by convection within the formalism of the full spectrum turbulence…
Astrophysical objects below the stellar mass limit but well above the mass of Jupiter eluded discovery for nearly three decades after Kumar first proposed their existence, and for two decades after Tarter proposed the name "brown dwarfs."…
Spallative nucleosynthesis is thought to be the only process capable of producing significant amount of Beryllium (Be) in the universe. Therefore, both energetic particles (EPs) and nuclei to be spalled (most efficiently C, N and O nuclei…
The Workshop 'The Magellanic Clouds and Other Dwarf Galaxies' was held at the Physikzentrum Bad Honnef in January 1998. The proceedings comprise 79 contributions. About 1/3 of the 352 pages contain the following Reviews: The Violent…
We investigate cosmological effects concerning the late-time entropy production due to the decay of non-relativistic massive particles. The thermalization process of neutrinos after the entropy production is properly solved by using the…
The GRAPE-4, the world's fastest computer in 1995-1997, has produced some major scientific results, through a wide diversity of large-scale simulations in astrophysics. Applications have ranged from planetary formation, through the…
We present detailed evolutionary calculations for carbon - oxygen - and helium - core white dwarf (WD) models with masses ranging from M= 0.1 to M= 1.2 solar masses and for metallicities Z= 0.001 and Z= 0. The sequences cover a wide range…
In this letter we give an account of the possible acceleration of protons in the outer radio lobes of the active galaxy PKS 1333-33. We also make estimates of the arrival energy spectrum.
We explore the possible impact of galactic and extragalactic foregrounds on measurements of the cosmic microwave background (CMB). We find that, given our present understanding of the foregrounds, they are unlikely to qualitatively affect…
The evolution of collapsing metal free protostellar clouds is investigated for various masses and initial conditions. We perform hydrodynamical calculations for spherically symmetric clouds taking account of radiative transfer of the…
The suggested alternative cosmology is based on the idea of barion symmetric universe, in which our home universe is a representative of multitude of typical matter and antimatter universes. This alternative concept gives a physically…
We numerically investigate chemodynamical evolution of major disk-disk galaxy mergers in order to explore the origin of mass-dependent chemical, photometric, and spectroscopic properties observed in elliptical galaxies. We particularly…
A significant fraction of clusters of galaxies are observed to have substructure, which implies that merging between clusters and subclusters is a rather common physical process of cluster formation. It still remains unclear how cluster…
We explore subtle variations in disk-integrated measurements spanning $\lsim$ 18 years of stellar surface magnetism by using a newly developed time-frequency gapped wavelet algorithm. We present results based on analysis of the Mount Wilson…
We examine whether isothermal models of the hot gas can successfully describe the ASCA and ROSAT spectra of NGC 1399, NGC 4472, NGC 4636, and NGC 5044. Broad-band spectral fitting of the ASCA SIS and GIS data accumulated within a radius of…
Recent observations by the Hubble Space Telescope suggest that a strong dynamical and morphological evolution of disk galaxies has occurred in clusters of galaxies. I present the result of the self-consistent high-resolution simulations of…
We analyze the star formation activity of an homogeneous LSB dwarf galaxy sample in the Virgo cluster, as a function of the radial velocity relative to the cluster mean velocity and the projected distance from the center of the cluster,…
Asteroids and comets dissipate energy when they rotate about the axis different from the axis of the maximal moment of inertia. We show that the most efficient internal relaxation happens at the double frequency of body's tumbling.…