ar X iv : a st ro - p h / 99 10 55 4 v 1 2 9 O ct 1 99 9 Galaxies of Redshift z > 5 : The View from Stony Brook

ar X iv : a st ro - p h / 99 10 06 5 v 1 4 O ct 1 99 9 The Interstellar Medium of Lens Galaxies

We use observations from the CASTLES survey of gravita-tional lenses to study extinction in 23 lens galaxies with 0 < z l < 1. The median differential extinction between lensed images is ∆E(B −V) = 0.05 mag, and the directly measured extinctions agree with the amount needed to explain the differences between the statistics of radio and (optical) quasar lens surveys. We also measure the first ex...

ar X iv : a st ro - p h / 99 10 19 9 v 1 1 2 O ct 1 99 9 A Companion Galaxy to the Post - Starburst Quasar UN J 1025 − 0040

UNJ1025−0040 is a quasar at z = 0.6344 that shows an extremely bright post starburst population of age ∼ 400 Myr (Brotherton et al. 1999). Images of UNJ1025−0040 show a nearly stellar object 4. 2 SSW of the quasar. We present imaging and spectroscopy that confirm that this object is a companion galaxy at redshift z = 0.6341. We estimate an age of ∼ 800 Myr for the dominant stellar population in...

ar X iv : a st ro - p h / 97 10 24 9 v 1 2 2 O ct 1 99 7 Searches for galaxies at z > ∼ 4 through Lyman – limit imaging

We present preliminary results of a search for galaxies at z > ∼ 4 through Lyman–limit imaging of the fields of known high–redshift radio–galaxies. Objects were selected by means of their broad–band colours, and spectroscopy of candidate objects in one of the fields has been performed through multi–slit spectroscopy at the 4.2m William Her-schel Telescope. These spectra show some of the first z...

ar X iv : a st ro - p h / 99 02 29 8 v 2 1 3 A pr 1 99 9 New limits on Ω Λ and Ω M from old galaxies at high redshift

ar X iv : a st ro - p h / 99 10 45 0 v 1 2 5 O ct 1 99 9 Population Synthesis of the GRB Progenitors and their Brightness and Redshift Distribution

We estimate the relativistic binaries merger rate and redshift distribution population synthesis of an ensemble of evolving close binaries. Results of such simulations definitely depend on the cosmic star formation rate history, which is different in galaxies of different types. This leads to a difference in merger rate in spiral and elliptical galaxies, which in principle can be an observation...