Cluster Ellipticals at High Redshift: The View from the Ground and with HST

New ground-based and HST observations of distant clusters make it possible to trace the history of E/S0 galaxies to lookback times of ~10 $h_{50}^{-1}$ Gyr. The data strongly favor a scenario in which cluster ellipticals formed very early with a narrow spread in ages. By z = 1.2 there are changes in color and luminosity consistent with simple passive evolution, but even at that redshift the galaxies appear mature, with red colors suggesting ages of several Gyr. Apparently we are still falling well short of seeing the true epoch of formation.Comment: 10 page postscript file including 6 figures, uuencoded, gzip-compressed, self-unpacking, and so forth. To appear in "Fresh Views on Elliptical Galaxies," proceedings of a conference held in Puebla, Mexico, 14-17 March 199

The Anthropocene Lyric: An Affective Geography of Poetry, Person, Place by Tom Bristow

Review of Tom Bristow\u27s The Anthropocene Lyric: An Affective Geography of Poetry, Person, Place

A new giant luminous arc gravitational lens associated with a z = 0.62 galaxy cluster, and the environments of distant radio galaxies

In the course of a survey investigating the cluster environments of distant 3CR radio galaxies, I have identified a previously unknown 'giant luminous arc' gravitational lens. The lensing cluster is associated with the radio galaxy 3C 220.1 at z = 0.62 and is the most distant cluster now known to produce such arcs. I present imaging and spectroscopic observations of the cluster and the arc, and discuss the implications for the cluster mass. At z greater than 0.6 the cluster velocity dispersions implied by such giant arcs may provide an interesting constraint on theories of large scale structure formation. The parent investigation in which this arc was identified concerns galaxy clusters and radio galaxy environments at 0.35 less than z less than 0.8. At the present epoch, powerful FR 2 radio galaxies tend to be found in environments of poor or average galaxy density. In contrast, at the higher redshifts investigated here, richer group and cluster environments are common. I present additional data on other clusters from this survey, and discuss its extension to z greater than 1 through a program of near-infrared and optical imaging

The Great Observatories Origins Deep Survey

The Great Observatories Origins Deep Survey (GOODS) is designed to gather the best and deepest multiwavelength data for studying the formation and evolution of galaxies and active galactic nuclei, the distribution of dark and luminous matter at high redshift, the cosmological parameters from distant supernovae, and the extragalactic background light. The program uses the most powerful space- and ground-based telescopes to cover two fields, each 10'x16', centered on the Hubble Deep Field North and the Chandra Deep Field South, already the sites of extensive observations from X-ray through radio wavelengths. GOODS incorporates 3.6-24 micron observations from a SIRTF Legacy Program, four-band ACS imaging from an HST Treasury Program, and extensive new ground-based imaging and spectroscopy. GOODS data products will be made available on a rapid time-scale, enabling community research on a wide variety of topics. Here we describe the project, emphasizing its application for studying the mass assembly history of galaxies.Comment: 8 pages, 2 figures, to appear in the proceedings of the ESO/USM Workshop "The Mass of Galaxies at Low and High Redshift" (Venice, Italy, October 2001), eds. R. Bender and A. Renzin

Two protogalaxy candidates in one night

In spite of a lookback time of 77 to 89 percent of the age of the universe, Lilly provided evidence that the dominant stellar population in 0902 was surprisingly old, over 1 Gyr. This age estimate was based on the values K = 18.8 and I-K = 4.5 in the central 3.5 x 3.5 inch. At Lilly's suggestion, we reobserved 0902 at K, and in initial reductions of our data found only an upper limit (K greater than 19.5). After extensive experimentation with reduction techniques and correction for low-level systematic effects, we succeeded in extracting a four sigma detection at K = 19.9 in a 4 inch diameter circular aperture. The morphology and location of this detection were more reminescent of the Ly alpha image than of CCD continuum images, and in Mar. 1992, we obtained a narrow band image which included redshifted (OIII) 4959,5007 A line emission at 2.20 microns. This (OIII) image gave a strong detection which demonstrates that most of the central K flux, already reduced by a magnitude, is due to line emission. Our formal line corrected values in a 4 inch aperture are K = 21.5 and R-K = 1.9. Hence, 0902 has been transformed from relaxed maturity into unsettled youth