NOT-SO DISTANT CLUSTERS

A small region of the core of the Coma cluster (z=0.023) taken with WFPC2 on board HST, this is part of a larger survey being analysed to determine the detailed morphologies of low luminosity galaxies within the Coma cluster. The image is roughly 60×45 arcsec in size and shows the wide variety of dwarf galaxies inhabiting the cluster environment. In addition to the luminous elliptical in the center of the frame there is a bright Sbc to the upper-right and a lower luminosity S0 at the bottom of the frame. The remainder of the low surface brightness galaxies within the image are dwarf ellipticals/spheroidals (either in nucleated or non-nucleated flavors). The numerous point sources around the luminous elliptical galaxy are probably globular clusters with intrinsic luminosities of Mv=-8 (h=1). The resolution of the image is roughly 30 pc at the distance of Coma (h=1).

A 2.7×2.7 Mpc region in the rich cluster A2345. This is a true color image, made from a composite of U/B/R images taken with the 40" Swope telescope of the Las Campanas Observatory, Chile. The exposure times were 2400s in U, 900s in B and 900s in R and the seeing was 1.2 arcsec. The full frame covers an area 12 times larger. Notice the preponderance of galaxies with similar colors to the bright central galaxy of the cluster (upper left) -- these are all likely to be elliptical and S0 galaxies in the cluster.

MAGIC-24 CLUSTERS

These are 600×600 pixel (2.8×2.8 arcmin) JPEG images of the central regions of the M-24 clusters taken with CCD13 on the 5-m (A1758 and A2146 cover larger regions). The images are real color constructed from the UBI exposures. No seeing corrections have been applied prior to stacking. These are 24 bit color images and are more easily viewed if they are downloaded and then manipulated with a viewer such as XV.

A1682

  • lilac, close pair E of 3rd brightest E?

    • A1704

  • blue, wide pair SE of cD?

    • A1758

  • blue arc SE of NW E, counter image?

    • A1763

  • nothing.

    • A1835

  • blue multiple arc SE of cent gal.

    • Zw7160

  • lilac arclet/pair NE of cD?

    • A2146

  • blue multiple arc E of SE E, in halo?

    • A2219

  • 2 (blue & lilac) multiple arcs.

    • A2261

  • blue multiple arc W of cD, counter image?

    • A2390

  • red straight arc.

    • ...and a couple of additions - first Abell 963 at z=0.21 this field is 7×7 arcmin and shows a true-color composite constructed from UBI images taken with the 4.2-m William Herschel Telescope on La Palma (really this needs to be viewed in 24-bit color with XV, rather than in a browser window).

    A2218 at z=0.18 - this field is 8.1×8.1 arcmin square and shows a true-color composite constructed from BVI images taken with the Hale 5-m at Palomar. Around 48,000s total integration went into this image, all in sub-arcsecond conditions. Note the z=0.08 foreground interacting galaxy with its low-surface brightness tidal features.

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    Last Modified: January 12th, 2000. [Netscape 2.0]