11 papers
An Automated Search for Extrasolar Planet Transits
M. G. Hidas, J. K. Webb, M. C. B. Ashley +3
We are setting up a new search for transiting extrasolar planets using the 0.5m Automated Patrol Telescope at Siding Spring Observatory, Australia. We will begin regular observatio…
Environmental Dependence of the Nature of Gaseous Envelopes of Galaxies at z < 1
Noriaki Yahata, Kenneth M. Lanzetta, John K. Webb +1
We present new statistical study on the origin of Lyman-alpha absorption systems that are detected in QSO fields. The primary objective is to investigate environmental dependence o…
The Hubble Deep Field-South QSO
Katrina M. Sealey, Michael. J. Drinkwater, John K. Webb +1
The Hubble Deep Field-South (HDF-S) was chosen to have a QSO (RA 22:33:37.6 Dec -60:33:29 J2000 and B=17.5) in the field to allow for studies of absorption systems intersecting the…
A High Deuterium Abundance at z=0.7; Evidence for Cosmic Inhomogeneity?
J. K. Webb, R. F. Carswell, K. M. Lanzetta +3
Recent HST/GHRS observations of the z = 0.7010 absorber toward the QSO 1718+4807 (selected because of apparently ideal characteristics for measuring D/H) yield a D/H significantly…
Limits on the Variability of Physical Constants
M. J. Drinkwater, J. K. Webb, J. D. Barrow +1
We have compared the frequency of high-redshift Hydrogen HI 21 cm absorption with that of associated molecular absorption in two quasars to place new (1 sigma) upper limits on any…
The Gaseous Extent of Galaxies and the Origin of \lya Absorption Systems at z < 1
H. -W. Chen, K. M. Lanzetta, J. K. Webb +1
We present initial results of a program to obtain and analyze HST WFPC2 images of galaxies in fields of HST spectroscopic target QSOs. The goal of the program is to investigate how…