October 1996 arXiv papers — page 16

Pablo Jensen, Hernán Larralde, Alberto Pimpinelli

We present a model for thin film growth by particle deposition that takes into account the possible evaporation of the particles deposited on the surface. Our model focuses on the formation of two-dimensional structures. We find that the presence of evaporation can dramatically affect the growth kinetics of the film, and can give rise to regimes characterize

P. Gondolo, R. Ansari, M. Auriere, P. Baillon

AGAPE is an observational search of massive compact halo objects (MACHOs) in the direction of M31 by means of a novel method: the gravitational microlensing of unresolved stars. The search consists in examining CCD pixel light curves for microlensing features. The high level of temporal stability necessary to detect microlensing events has been achieved, wit

Victor P. Debattista, J. A. Sellwood

We describe fully self-consistent N-body experiments of barred galaxies with massive halos. A rotating bar is braked through dynamical friction with the halo, which occurs on a short time scale when the central density of the halo is high. On the other hand, friction is weak in a model with a central halo density low enough that the disk dominates the rotati

Wei Cui, Dan Feldkun, Robert Braun

We report the results from a deep ROSAT PSPC observation of LINER galaxy NGC 4736. Two bright sources are detected, separated by only about 1', with the brighter one coinciding with the center of the galaxy. Neither source shows apparent X-ray variability on time-scales of minutes to hours in the ROSAT band. Simple power-law models, typical of AGN X-ray

S. Cristiani, S. D'Odorico, V. D'Odorico, A. Fontana

We analyze the clustering properties of a high-resolution (~10 km/s) sample of about 1600 Lyman-alpha lines in the spectra of 15 quasars, obtained in the framework of an ESO key-programme with the addition of literature data. The two-point correlation function in the velocity space shows a significant signal on small velocity scales (Delta v < 300 km/s) with

S. Campana, S. Mereghetti, L. Sidoli

An unusual X-ray source, RXJ1856.5-3754, has recently been discovered with ROSAT: its spectrum resembles that of supersoft sources, but the very high X-ray to optical flux ratio excludes the presence of a companion star, pointing to an isolated compact object. It has been proposed that RXJ1856.5-3754 is an old, isolated neutron star accreting from the inters

David H. Weinberg

The structure of galaxies, the nature of dark matter, and the physics of galaxy formation were the interlocking themes of DM 1996: Dark and Visible Matter in Galaxies and Cosmological Implications. In this conference summary report, I review recent observational and theoretical advances in these areas, then describe highlights of the meeting and discuss thei

Kohji Tomisaka

Accretion flow in a contracting magnetized isothermal cloud was studied using magnetohydrodynamical simulations and a nested grid technique. First, the interstellar magnetized cloud experiences a ``runaway collapse&#39;&#39; phase, in which the central density increases drastically within a finite time scale. Finally, it enters an accretion phase, in which i

Alexander V. Sardo Infirri

Let $X$ and $Y$ be two analytic canonical Gorenstein orbifolds. A resolution of singularities $Y\to X$ is called an Euler resolution if $Y$ and $X$ have the same orbifold Euler number. If $Y$ is only terminal rather than smooth, it is called an Euler terminalisation. It is proved that Euler terminalisations exist for toric varieties in any dimension, for 4-d