ar X iv : a st ro - p h / 01 01 31 5 v 1 1 8 Ja n 20 01 Signal Characteristics from Electromagnetic Cascades in Ice

ar X iv : a st ro - p h / 01 01 31 5 v 2 2 6 Fe b 20 02 Signal Characteristics from Electromagnetic Cascades in Ice

We investigate the development of electromagnetic cascades in ice using a GEANT Monte Carlo simulation. We examine the Cherenkov pulse that is generated by the charge excess that develops and propagates with the shower. This study is important for the RICE experiment at the South Pole, as well as any test beam experiment which seeks to measure coherent Cherenkov radiation from an electromagneti...

ar X iv : a st ro - p h / 97 01 22 8 v 1 2 9 Ja n 19 97 Large - scale Structures revealed by Wavelet Decomposition 1

ar X iv : a st ro - p h / 02 01 31 6 v 1 1 8 Ja n 20 02 New Approach to Sgr A * Problem

The hypothesis that radiation of Sgr A* is caused by accretion onto a supermassive compact object without the events horizon is studied. The main equations of the accretion and a relativistic equation of the trasfer radiation are obtained. The synchrotron spectrum in the vicinity of the maximum is considered.

ar X iv : a st ro - p h / 01 01 43 8 v 1 2 4 Ja n 20 01 NUCLEAR

Observations of metal-poor Galactic halo stars indicate that the abundance pattern of the (heaviest) neutron-capture elements is consistent with the scaled solar system r-process abundances. Utilizing the radioactive (r-process) element thorium, age determinations have been made for several of these same stars, placing constraints on both Galactic and cosmological age estimates.

ar X iv : a st ro - p h / 01 01 17 1 v 1 1 1 Ja n 20 01 PRELIMINARY RESULTS FROM THE COSMIC BACKGROUND IMAGER

The Cosmic Background Imager (CBI) is a 13-element interferometer designed to image intrinsic anisotropies in the cosmic microwave background (CMB) on arcminute scales. A review of the capabilities of the instrument is presented, together with a discussion of observations which have been taken over the past 9 months from the Atacama desert of Chile. We present preliminary high-resolution mosaic...