The possibility of using high-data-rate optical transmitters for satellite communication has generated interest in laser communication systems for ground-to-space and space-to-ground data links. Among the parameters useful to model propagation along a vertical path are the refractive index structure constant Cn2 profile and boundary layer turbulent

We present the first results of a study of the morphology, kinematics and ionization structure of infrared (IR) mergers/quasi-stellar objects (QSOs) with galactic winds. This study is based mainly on INTEGRAL two-dimensional (2D) fibre spectroscopy [obtained on the 4.2-m William Herschel Telescope (WHT), La Palma] combined with high-resolution

We demonstrate that single and binary star clusters can be formed during cloud-cloud collisions triggered by the tidal interaction between the Large and Small Magellanic clouds. We run two different sets of self-consistent numerical simulations that show that compact, bound star clusters can be formed within the centers of two colliding clouds as a

We report on a Chandra observation of the transient low-mass X-ray binary and type-I X-ray burst source 2S 1711-339 (Carpenter et al. 1977,MNRAS,179,270; Wilson et al. 2003,ApJ,596,1220). The 2S 1711-339 region was observed with the Chandra ACIS-S3 CCD array for 25 ks on 2003 February 07. A total of 64 counts were detected from a source at R.A. =

The experimental study of laser beam propagation in turbulence is relevant to fields such as adaptive optics and optical communications. Turbulence sensing for astronomical purposes requires a convergent laser beam adequately focused on the sodium mesospheric layer. Free Optical communications ground-to-satellite usually are based on divergent

The observed masses of the most massive stars do not surpass about 150 Msolar. This may either be a fundamental upper mass limit which is defined by the physics of massive stars and/or their formation, or it may simply reflect the increasing sparsity of such very massive stars, so that the observation of even higher mass stars becomes unlikely in