To better understand the mechanism or mechanisms that lead to AGN activity today, we measure the X-ray AGN fraction in a new sample of nearby clusters and examine how it varies with galaxy properties, projected cluster-centric radius, and cluster velocity dispersion. We present new wide-field Chandra X-ray Observatory observations of Abell 85, Abell 754 and the background cluster Abell 89B out ...

We present a statistical analysis of the properties of galaxies containing ultraluminous X-ray objects (ULXs). Our primary goal is to establish the fraction of galaxies containing a ULX as a function of ULX luminosity. Our sample is based on ROSAT HRI observations of galaxies. We find that ∼ 12% of galaxies contain at least one ULX with LX > 10 39 erg sand ∼ 1% of galaxies contain at least one ...

A study of the globular cluster systems of 23 brightest, or central, galaxies in 19 Abell clusters has recently been completed (Blakeslee 1997). This letter presents some of the newly discovered correlations of the globular cluster specific frequency SN in these galaxies with other galaxy and cluster properties and puts forth an interpretation of these results. SN is found to correlate strongly...

We present deep 850μm imaging of the z=0.773 strong lensing galaxy cluster RCSJ022434-0002.5 from the Red-Sequence Cluster Survey (RCS). These data are part of a larger submillimeter survey of RCS clusters, with SCUBA on the JCMT. We find five objects at 850μm, all of which are also detected at either 1.4-GHz, 450μm or both. The number density of objects in this field is in general agreement wi...

We study the dependence of galaxy properties on the clustercentric radius and the environment attributed to the nearest neighbor galaxy using the Sloan Digital Sky Survey (SDSS) galaxies associated with the Abell galaxy clusters. We find that there exists a characteristic scale where the properties of galaxies suddenly start to depend on the clustercentric radius at fixed neighbor environment. ...

Redshift Survey Compact Groups (RSCGs) are tight knots of N ≥ 3 galaxies selected from the CfA2+SSRS2 redshift survey. The selection is based on physical extent and association in redshift space alone. We measured 300 new redshifts of fainter galaxies within 1h Mpc of 14 RSCGs to explore the relationship between RSCGs and their environments. 13 of 14 RSCGs are embedded in overdense regions of r...

We present new results on the Fundamental Plane of galaxies in two rich clusters, Cl1358+62 at z = 0.33 and MS2053–04 at z = 0.58, based on Keck and HST observations. Our new data triple the sample of galaxies with measured Fundamental Plane parameters at intermediate redshift. The early-type galaxies in these clusters define very clear Fundamental Plane relations, confirming an earlier result ...

The most simple observed cases of gravitational lensing of distant quasars and galaxies by galaxies and clusters of galaxies are used to test Einstein’s theory of General Relativity and Newtonian Gravity over galactic and intergalactic distances. They extend the distance range over which Newton-Einstein Gravity has been tested by 10 orders of magnitude. Although the precision of the tests are f...

We present spectroscopic and photometric data for 920 galaxies selected in 68 fields of the Aquarius Cluster Catalog. Typically the 15 brightest candidate members with magnitudes in the range 16 < bJ < 21 were selected for observations, and ∼ 71% turn out to be cluster members. Using the new redshift determinations we assign galaxies to groups and clusters, and by including data from the litera...

This work presents high S/N spectroscopic observations of a sample of six suspected merger remnants, selected primarily on the basis of Hi tidal debris detections. Single stellar population analysis of these galaxies indicates that their ages, metallicities, and α-enhancement ratios are consistent with those of a representative sample of nearby elliptical galaxies. The expected stellar populati...