Left: K-band image. Boxes are spec. confirmed cluster members. Circles probable cluster members based on their colours.
Middle: I-band image with ROSAT PSPC contours overlayed.
Right: CM diagrams for 2 arcmin. field around cluster center. Filled symbols are galaxies inside a 35 arcsec radius. Circles are spec. cluster members, squares foreground spec. galaxies. Dashed lines represent a predicted no-evolution locus for early-type galaxies based on the Coma Cluster.

Left: BIK composite, 2 x 2 arcmin, with Chandra X-ray contours overlayed.
Right: CM diagrams for 9 arcmin² field around cluster center. Filled symbols are galaxies inside a 35 arcsec radius. Circles are spec. cluster members, squares foreground spec. galaxies. Dashed lines represent a predicted no-evolution locus for early-type galaxies based on the Coma Cluster.

Left: iJK composite, 2.5 x 2.5 arcmin. Green boxes are spec. confirmed cluster members. Red circles probable cluster members based on their colours.
Middle: I-band image with ROSAT PSPC contours overlayed.
Right: Color-magnitude diagrams from a 200 arcsec area surrounding RDCS J0910+5422, showing 1 sigma error bars in the color and spectroscopic members (circles). The dotted lines in each panel show the no-evolution prediction for early-type galaxies at the cluster redshift, based on the observed colors of Coma early types.

Left: K-band images centered on the brightest galaxy in each of the two X-ray lobes of RX J105343+5735. The galaxy in the Eastern lobe for which we obtained a spectroscopic redshift is identified with the arrow.
Middle: The ROSAT HRI contours of the cluster RX J1053.7+5735 overlaid on the color image made from V, R, and I (color coded in blue, green, and red) band exposures. North is up and East is left.
Right: Color-magnitude diagram for the RX J105343+5735 field. Data from the eastern lobe are plotted with filled circles, the western lobe with filled triangles.

Left: 3.5 x 3.5 arcmin I-band NOT image.
Middle and Right: Chandra images (0.4-8 keV)

Left: 5.25 x 5.25 arcmin NTT SOFI field. The large circle marks the central parts of the cluster with a radius of 45 arcsec. Blue circles mark spec. confirmed members. Red circles mark objects with (J-K)-color consistent with that of the spec. confirmed members ((J-K) in between 1.9 and 2.1).
Right: Color-magnitude diagram incl. galaxies within a radius of 45 arcsec. Filled symbols mark expected cluster members, squares spec. confirmed members.

Parameters for z>1 clusters

Name	R.A.a	Dec.a	z	fXb	LX	T	e	Selection
RX J0848.9+4452	08 48 56.2	+44 52 00	1.26	1.4+/-0.2c	0.51d	5.8	- (6)	X-ray
RXJ 0848.6+4453	08 48 34.2	+44 53 35	1.27	0.44+/-0.08c	0.40d	1.6	650+/-170 (9)	NIR
RDCS J0910+5422	9 10 44.9	+54 22 08.9	1.11	1.06f	2.48g	7.2	- (9)	X-ray
RXJ 1053.7+5735	10 53.7	+57 35	1.26	3.0h	3.4i	4.9+1.5-0.9	- (10)	X-ray
EIS 0954-2023	09 54 47.5	-20 23 55.2	1.14	-	-	-	550 (5?)	NIR
MG 2016+112	20 19 18.15	+11 27 08.3	1.004	-	< 1.7	-	771 (6)	X-ray

     NOTES
     ^aPosition of the X-ray centroid.
     ^bUnabsorbed flux in units of 10^-14 ergs/s/cm².
     ^c r = 35 aperture, 0.5-6 keV band.
     ^d0.5-2 keV luminosity in units of 10⁴⁴ ergs/s with H₀ = 65 km/s/Mpc, _m = 0.3, and = 0.7.
     ^eVelocity dispersion in km/s and no. of galaxies with concordant redshift.
     ^f0.5-2 keV flux within 38.8 arcsec aperture.
     ^gBolometric luminosity in units of 10⁴⁴ ergs/s with H₀ = 65 km/s/Mpc, _m = 0.3, and = 0.7.
     ^h0.2-10 keV flux within an elliptic region with semi-axes 0.6 and 0.9 arcmin.
     ^gBolometric luminosity in units of 10⁴⁴ ergs/s with H₀ = 50 km/s/Mpc, q₀=0.5.

Left: Keck NIRC K-band image of 3C 294. The bright star 10 arcsec west of the radio galaxy was used as a guide star for the adaptive optics observations. H-band image of 3C 294 obtained with SCAM on NIRSPEC behind the Keck adaptive optics system. North is up and east to the left. The bright core of the eastern component is unresolved; its diameter is less than 0.05 arcsec. A. Quirrenbach et al., 2001, ApJ, 556, 108. .
Middle: X-ray colour map. 0.5-1 keV emission is red, 1-2 keV emission is green, and 2-5 keV emission is blue. Data have been binned by 1 arcsec and smoothed by 1 arcsec. Approx. 1.2 arcmin a side.
Right: Grey scale smoothed image with radio (tightly bunched contours) and Ly_alpha (more open contours) emission superposed.

Left: Composite pseudo-color picture of the observed 3C 324 field. The RGB colors are assigned for , I, and images, respectively. The dashed line outlines the field of the HST observation; i.e., the upper-right region of the dashed line has not been observed with the HST. .
Middle: Distribution of the 35 cluster members on the sky. The areas of filled circles are in proportion to the brightness of galaxies. The dashed line shows the boundary of the field of the HST observation. The large circle indicates the `inner region'.
Right: The filled circles indicate cluster members, and the small open circles indicate non-members. The filled square in each panel shows 3C 324, and the long-dashed line in each panel shows the 3-sigma detection limit of and I_AB, respectively. The solid line corresponds to a predicted color-magnitude relation of passively evolving galaxies formed at z=4.5. Eight bright galaxies, which make a tight color-magnitude relation, are indicated by double circles. The short dashed line in each panel shows a fit of a straight line to these 8 galaxies with its slope fixed to that of the model prediction.

Left: Three-color representation of the field around the quasar B2 1335+28. The blue, green, and red images correspond to the R-, I- and K-band frames, respectively.
Right: "Recovered" C-M sequence for the cluster galaxies. The symbols with small filled circles show the galaxies having colors consistent with the passive evolution model and without UV excess. The dashed line shows the predicted C-M relation at z = 1.1 (zf = 4.4). The solid lines are the z = 1.1 colors of the Coma C-M model for ages between 0.5 and 7 Gyr (note that the age of the universe at z = 1.1 is 4.3 Gyr in our cosmology).

Parameters for z>1 cluster candidates

Name	R.A.a	Dec.a	z	fX	LX	T	e	Selection
3C294	14 06 44.0	+34 11 25	1.79	-	4.5a		- (6)	Radio/X-ray
3C324	15 49 48.9	+21 25 38	1.2	-	-	-	- (6)	Radio/NIR
B2 1335+28			1.1	-	-	-	- (6)	Radio/NIR

     NOTES
     ^a0.3-10 keV luminosity in units of 10⁴⁴ ergs/s with H₀ = 50 km/s/Mpc, q₀= 0.5.