相关论文: Narrow Band Continuum Colors of Distant Cluster Po…
We combine new narrow band photometry with archival WFPC2 data for A2218 ($z$=0.18) and A2125 ($z$=0.25), two clusters with intermediate redshifts but very different cluster properties, in order to examine the evolution of galaxy…
This paper presents four color narrow-band photometry of clusters A115 ($z=0.191$) and A2283 ($z=0.182$) in order to follow the star formation history of various galaxy types. Although located at similar redshifts, the two clusters display…
We present a deep UBI CCD survey using the Palomar 5-m telescope of a sample of high X-ray luminosity, distant clusters selected from the ROSAT All-Sky Survey. The 10 clusters lie at z=0.22-0.28, an era where evolutionary effects have been…
We present the evolution of the color-magnitude distribution of galaxy clusters from z = 0.45 to z = 0.9 using a homogeneously selected sample of ~1000 clusters drawn from the Red-Sequence Cluster Survey (RCS). The red fraction of galaxies…
We present gri CCD photometry of 44 Abell clusters and 4 cluster candidates. Twenty one clusters in our sample have spectroscopic redshifts. Fitting a relation between mean g, r and i magnitudes, and redshift for this subsample, we have…
We present a color analysis of the galaxy populations of candidate clusters of galaxies from the Palomar Distant Cluster Survey (Postman et al.\ 1996). The survey was conducted in two broad band filters that closely match $V$ and $I$ and…
This paper presents deep narrow band photometry of the cluster A2317 (z=0.211) carried out using KPNO 4 m and Steward 2.3 m telescopes. Using rest frame Stromgren photometry, it is determined that A2317 has an unusually high fraction of…
We report a detailed optical study of the clusters Abell 2125 and 2645. Both clusters have z=0.25 and richness class 4, yet contrast strongly in blue fraction and radio galaxy population. We find 27 spectroscopically confirmed radio…
We present the results of Butcher-Oemler-style analysis of three moderate- redshift (0.1<z<0.2) clusters which have bimodal X-ray surface brightness profiles. We find that at least two of these clusters exhibit unusually high fractions of…
Using data of five clusters of galaxies within the redshift range 0.15 $\leq$ z $\leq$ 0.25, imaged with the Nordic Optical Telescope (NOT) in the central $\approx$ 1 Mpc$^2$ in very good seeing conditions, we have performed an exhaustive…
Based on a deep ROSAT/PSPC observation, we reveal an elongated complex of extended X-ray-emitting objects in and around the galaxy cluster A2125. Multicolor optical imaging of galaxies in the field suggests that this complex represents a…
Red sequence galaxies form with an intense burst of star formation in the early universe to evolve passively into massive, metal rich, old galaxies at z ~ 0. But Abell 1314 (z=0.034) is found to host almost all red sequence galaxy members…
We present uniform CFHT Megacam g and r photometry for 34 X-ray selected galaxy clusters drawn from the X-ray Multi-Mirror (XMM) Large Scale Structure (LSS) survey and the Canadian Cluster Comparison Project (CCCP). The clusters possess…
Two-dimensional surface photometry is presented for a sample of 351 late-type galaxies with $0.12 < z < 0.65$. These objects are drawn from the Canadian Network for Observational Cosmology (CNOC) cluster survey and are either…
We previously reported a significant clustering of red galaxies (R-K=3.5--6) around the radio-loud quasar B2 1335+28 at z=1.086. In this paper, we establish the existence of a rich cluster at the quasar redshift, and study the properties of…
We have observed three fields of the Coma cluster of galaxies with a narrow band (modified Stromgren) filter system. Observed galaxies include 31 in the vicinity of NGC 4889, 48 near NGC 4874, and 60 near NGC 4839 complete to M_5500=-18 in…
We present multi-fiber spectroscopy and broadband imaging of early-type galaxies in five nearby rich clusters of galaxies. The main purpose was to look for ``abnormal'' spectrum galaxies (i.e., post-starburst galaxies which have strong…
The galaxy population in the intermediate-redshift ($z=0.228$) rich cluster Abell 2390 is investigated. We present velocities, colors, and morphological information for an exceptionally large sample of 323 galaxies (216 cluster members) in…
Although field galaxy studies have begun to probe the universe at z > 1, evidence for galaxy clusters at such redshifts has been sparse. New observations are accumulating rapidly, however, providing new data on the early evolution of…
We have investigated the redshift evolution of the colour--cluster-centric-radius relation and the morphology--cluster-centric-radius relation in three redshift bins, $0.02\leq z\leq 0.14$, $0.14< z\leq 0.20$, and $0.20< z\leq 0.30$ using a…