Below: Three different stretches of a BJK `true' color composite of the core of the cluster A2218 (z=0.18), you can compare this view with that from the HST optical image. The field of view is roughly 190" square and the seeing on the JK frames is 0.7-0.8", the B image is from the Hale 5-m and has 1.2" seeing.

     

Below: A real color B/V/I image of the core region of A2218 (z=0.171) taken with WFPC2/HST as an Early Release Observation after SM3a. The various blue high-z arcs are easily visible, as is the z=0.702 lensed elliptical galaxy behind the cluster. This image comprises 15 orbits of exposure in F450W, F606W and F814W and thus represents about $3M worth of data.

  

Below: The top two rows show the Chandra source CXOUJ215334.0+174240 as seen in hard X-rays (using two different false color maps and at two different pixel scales). The upper panels have 0.5-arcsec pixels, while the lower panels are resampled to 0.25-arcsec pixels. Both sets of panels are smoothed with a 0.8-arcsec FWHM gaussian for display purposes.

The lower three panels show the optical counterpart identified in an archival HST WFPC2 image of the field. The HST imaging is in F555W (V) and F814W (I) visual and near-infrared bands. The lower left-hand panel is a `true' color representation of the field, while the two right-hand panels show a false color view of the composite image using two different false color maps.

In all cases the panels are 10-arcsec square with North top and East to the left. Note these images are JPEGs and the color tables will look much better if viewed with a tool other than a browser.

  

  

     

Below: A 7.5× 7.5 arcmin mosaic of A851 (z=0.41) taken with WFPC2/HST for the MORPHS program. This figure shows the raw shear field measured from the faint galaxies in the field overlayed as a vector field along with a contour plot of the X-ray emission from the cluster. The weak lensing signal suggests that the cluster is very massive.

  

Below: A true color I/K image of A851 (z=0.41) constructed from a wide-field 5x5 mosaic taken with UFTI on UKIRT in Feb/Mar 1999. The full mosaic is 7.5× 7.5 arcmin in size with an effective exposure time of 2.4ks per pointing (25 pointings) and a median seeing of 0.5 arcsec FWHM for the whole mosaic (some frames are sub-0.4 arcsec). This subsection is 5.3× 6.8 arcmin to match the size of the Keck I image (taken in collaboration with Len Cowie and Amy Barger). The core of the cluster is dominated by half-a-dozen large ellipticals (seen in the centre of the field).

  

Below: A false color K image of a single pointing from the A851 UFTI mosaic. This frame is 92× 92 arcsec in size, has an exposure time of 2.4ks and seeing of ~0.45 arcsec (around 3 kpc at the cluster redshift for Ho=50/qo=0.5). Weak spiral arms are visible in the bright galaxy in the center of the frame and several of the other brighter galaxies can be easily morphologically classified as S0 or E.

  

Below: A true color image of a 60 × 60 arcsec region (roughly 400 kpc across at the cluster redshift) from the A851 UFTI mosaic. The frame shows a compact clump of galaxies on the edge of the cluster which are probably being accreted onto the cluster core. The effects of dust are evident in the colours of several of the spiral galaxies in the centre of the field as well as being seen in their HST morphologies. The reddest of the three galaxies in the field centre is also detected in a deep 1.4GHz VLA radio map of the cluster suggesting that it hosts an obscured starburst. A faint, extended K source is visible to the south-west of the field centre, this is undetected in the deep R/I images giving it a very red galaxy indicating that it has I-K>6 and is thus an Extremely Red Object. This image is created from R, I and K images, taken with WFPC2/HST, LRIS/Keck and UFTI/UKIRT respectively.

  

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