Neutral hydrogen observations of four MKW-AWM poor clusters

We present the results of a study on galaxy interactions, tides, and other processes which produce luminous fine-scale substructures in the galaxy clusters: Coma, Perseus, Abell 2199, AWM 3 and AWM 5. All unusual structures in these clusters can be categorized in seven morphologies: interacting galaxies, multiple galaxies (non-interacting), distorted galaxies, tailed galaxies, line galaxies, dwarf galaxy groups and galaxy aggregates. The various morphologies are described, and a catalog is presented of 248 objects in these five clusters along with color, and positional information obtained from CCD images taken with the WIYN 3.5m telescope in broadband B and R filters. Distorted, interacting, and fine-scale substructures have a range of colors extending from blue objects with B-R $\approx$ 0, to redder colors at B-R $\approx$ 2.5. We also find that the structures with the most disturbed morphology have the bluest colors. Additionally, the relative number distributions of these structures suggests that two separate classes of galaxy clusters exist: one dominated by distorted structures and the other dominated by galaxy associations. The Coma and Perseus clusters, respectively, are proposed as models for these types of clusters. Possible mechanisms for the production of fine-scale substructure are reviewed and compared to observations of z $\approx$ 0.4 Butcher-Oemler clusters. We conclude, based on color, positional, and statistical data, that the most likely mechanism for the creation of these structures is through an interaction with the gravitational potential of the cluster, possibly coupled with effects of high speed interactions with large cluster ellipticals.Comment: To appear in January AJ, 47 Page Manuscript with 21 Figure

Section: Awm 3 and Awmmentioning

confidence: 84%

Tides, Interactions, and Fine-Scale Substructures in Galaxy Clusters

Conselice

Gallagher

1999

“…Early optical studies of AWM/MKW systems lack extensive photometry and complete redshift samples (Beers et al 1984, 1995 andreferences therein;Malumuth & Kriss 1986;Williams & Lynch 1991, Price et al 1991Dell'Antonio et al 1995). AWM 7 is particularly problematic because it spans two Palomar Sky Survey plates with rather different sensitivities, making consistent photographic magnitude determination difficult.…”

Section: Introductionmentioning

confidence: 99%

A Photometric and Kinematic Study of AWM 7

Koranyi

Geller

Mohr

et al. 1998

We have measured redshifts and Kron-Cousins R-band magnitudes for a sample of galaxies in the poor cluster AWM 7. We have measured redshifts for 172 galaxies; 106 of these are cluster members. We determine the luminosity function from a photometric survey of the central 1.2 h^{-1} x 1.2 h^{-1} Mpc. The LF has a bump at the bright end and a faint-end slope of \alpha = -1.37+-0.16, populated almost exclusively by absorption-line galaxies. The cluster velocity dispersion is lower in the core (\sim 530 km/s) than at the outskirts (\sim 680 km/s), consistent with the cooling flow seen in the X-ray. The cold core extends \sim 150 h^{-1} kpc from the cluster center. The Kron-Cousins R-band mass-to-light ratio of the system is 650+-170 h M_\odot/L_\odot, substantially lower than previous optical determinations, but consistent with most previous X-ray determinations. We adopt H_0 = 100 h km/s/Mpc throughout this paper; at the mean cluster redshift, (5247+-76 km/s), 1 h^{-1} Mpc subtends 65$\farcm$5.Comment: 37 pages, LaTeX, including 12 Figures and 1 Table. Accepted for publication in the Astronomical Journa

“…This H I deficiency is usually attributed to the process of ram pressure sweeping. In a similar way Williams & Lynch (1991) detected a lower than average gas content for the spiral members in four poor clusters, while Williams & van Gorkom (1988);and Williams & Rood (1987) detected a similar effect when analyzing a few compact groups. Haynes (1981) found the presence of neutral hydrogen streams in 6 out of 15 groups of galaxies.…”

mentioning

confidence: 53%

Study of a Slice at +9° to +15° of Declination. I. The Neutral Hydrogen Content of Galaxies in Loose Groups

Maia

Willmer

Costa³

1998

We examine the H I content of spiral galaxies in groups by using a catalog of loose groups of galaxies identiÐed in a magnitude-limited sample spanning the range 8h ¹ a ¹ 18h in right ascension (m Z ¹ 15.7) and ]9¡ ¹ d ¹ ]15¡ in declination. The redshift completeness of the galaxy sample is approximately 95%. No signiÐcant e †ect of H I depletion is found, although there may be a hint that the earliest type spirals are slightly deÐcient.