The RDCS1252 Home Page

RDCS1252.9-2927, at redshift z=1.237, is one of the most distant massive galaxy clusters known. It was selected from the ROSAT Deep Cluster Survey and confirmed with near-IR observations and optical spectroscopy with ESO telescopes. RDCS1252 has become the center of a multi-wavelength campaign with ground-based and space observatories, which includes deep J&Ks imaging with VLT/ISAAC, BVRIz imaging with VLT/FORS, extensive spectroscopy with FORS, Chandra and XMM observations, HST/ACS deep imaging in i&z bands, and Spitzer/IRAC observation at 3-8 microns.
In this page, we collect related papers and material, and will soon (2007) start releasing reduced data products.

Related Papers
Image Gallery  
Press Releases & Highlights

Related Papers

Title: VLT and ACS observations of RDCS J1252.9-2927: dynamical structure and galaxy populations in a massive cluster at z=1.237
        Astrophysical Journal, 2007, in press  [astro-ph]

Authors: R. Demarco, P. Rosati, C. Lidman, M. Girardi, M. Nonino, A. Rettura, V. Strazzullo, et al.

Title: A Deficit of Faint Red Galaxies in the Possible Large-Scale Structures around the RDCS J1252.9-2927 Cluster at z=1.24
        Astrophysical Journal, 2007, in press  [astro-ph]

Authors: M. Tanaka, T. Kodama, M. Kajisawa, R. Bower, R. Demarco, A. Finoguenov, C. Lidman, P. Rosati

Title: The near-infrared luminosity function of cluster galaxies beyond redshift one
        Astronomy&Astrophysics, 2006, 450, 909 [pdf]  [astro-ph]

Authors: V. Strazzullo, P. Rosati, S.A. Stanford, C. Lidman, M. Nonino, R. Demarco, P.E. Eisenhardt, S.Ettori, V.Mainieri, S. Toft

Title: HST/ACS Weak Lensing Analysis of the Galaxy Cluster RDCS1252.9-2927 at z=1.24
        Astrophysical Journal, 2005, 623, 42 [pdf]  [astro-ph]

Authors: M.Lombardi, P.Rosati, J.P.Blakeslee, S.Ettori, R.Demarco, H.C.Ford, G.D.Illingworth, M.Clampin, G.F.Hartig, N.Benitez, T.J.Broadhurst, M.Franx, M.J.Jee, M.Postman, and R.L.White

Title: The Fundamental Plane of Cluster Ellipticals at z = 1.25
        Astrophysical Journal, 2005, 620, L83  [astro-ph]  [pdf]

Authors: B.P.Holden, A.van der Wel, M.Franx, G.D.Illingworth, J.P Blakeslee, P.van Dokkum, H.Ford, D.Magee, H.-W.Rix, P.Rosati

Title: K-band Luminosity Function of the z=1.237 Cluster of Galaxies RDCS J1252.9-2927
        Astronomy&Astrophysics, 2004, 422, 29 [astro-ph] [ps] [pdf]

Authors: S.Toft, V.Mainieri, P.Rosati, C.Lidman, R.Demarco, M.Nonino, S.A.Stanford

Chandra and XMM-Newton Observations of RDCS1252.9-2927,
         A Massive Cluster at z=1.24
        Astronomical Journal, 2004, 127, 230 [pdf] [astro-ph] [ps][pdf]
Authors: P.Rosati, P.Tozzi, S.Ettori, V.Mainieri, R.Demarco, S.A.Stanford, C.Lidman, M.Nonino, S.Borgani, R.Della Ceca, P.Eisenhardt, B.P.Holden, C.Norman

Title: Advanced Camera for Surveys Photometry of the Cluster RDCS1252.9-2927:  
        The Color-Magnitude Relation at z=1.24
        ApJ Letters
, 2003, 596, L143 [pdf]  [astro-ph]
Authors: J. P. Blakeslee, M. Franx, M. Postman, P. Rosati, B. P. Holden, G. D. Illingworth, H. C. Ford, N. J. G. Cross, C. Gronwall, N. Benitez, R. J. Bouwens, T. J. Broadhurst, M. Clampin, R. Demarco, D. A. Golimowski, G. F. Hartig, L. Infante, A. R. Martel, G. K. Miley, F. Menanteau, G. R. Meurer, M. Sirianni, R. L. White

Title:Deep near-infrared imaging of RDCS J1252.9-2927, at z=1.237:
        The colour-magnitude diagram
       Astronomy&Astrophysics, 2004, 416, 829 [pdf] [astro-ph]
Authors: C.Lidman, P.Rosati, R.Demarco, M.Nonino, V.Mainieri, S.A.Stanford, S.Toft

Title: Star Formation at z~6: i-dropouts in the ACS GTO fields
         Astrophysical Journal, 2003, 595, 589 [pdf]  [astro-ph]

Authors: R.J. Bouwens, G.D. Illingworth, P. Rosati, C. Lidman, T. Broadhurst, M. Franx, H.C. Ford, D. Magee, N. Benitez, J.P. Blakeslee, G.R. Meurer, M. Clampin, G.F. Hartig, D.R. Ardila, F. Bartko, R.A. Brown, C.J. Burrows, E.S. Cheng, N.J.G. Cross, P.D. Feldman, D.A. Golimowski, C. Gronwall, L. Infante, R.A. Kimble, J.E. Krist, M.P. Lesser, A.R. Martel, F. Menanteau, G.K. Miley, M. Postman, M. Sirianni, W.B. Sparks, H.D. Tran, Z.I. Tsvetanov, R.L. White, W. Zheng

Title: X-ray Clusters at High Redshift   [ps],
       In Carnegie Observatories Astrophysics Series, Vol. 3 (2003): Clusters
          of Galaxies: Probes of Cosmological Structure and Galaxy Evolution , ed. J. S.
          Mulchaey, A. Dressler, and A. Oemler (Cambridge: Cambridge Univ. Press)
P. Rosati

Image Gallery

(Rosati et al. 2004, Fig.6)
Color composite image of RDCS1252 with overlaid Chandra contours. The image is 2 arcmin across, or 1 Mpc at z=1.24. It was obtained by combining optical and near-IR bands from FORS and ISAAC on the VLT: B+V, R+z, J+Ks. Contours show the smoothed X-ray emission with a gaussian FWHM of 5" at levels 3, 5, 10, 20 sigma above the background (N is up, E to the left).

A different representation of the image to the left:
blinking between the optical-nearIR color image and the hot gas distribution (in red) from the Chandra smoothed image in the 0.5-2 keV band. See also the Chandra Press Release to zoom into this image.

(Rosati et al. 2004, Fig.1a)
Chandra ACIS-I 188 ksec observations in the 0.5-2 keV band showing 9.6'x8.1' field around RDCS1252 (a serendipitous low redshift group, CXOU J1252.6-2925, is also visible). The image has been smoothed by a gaussian with sigma=2" and the grey-scale has a square root scaling.

Right: X-ray color, adaptively smoothed image of the same field (composite of the three energy bands [0.5-1], [1-2], [2-7] keV), showing a sharp edge in the surface brightness distribution (west of the core, possibly a cold front). The Chandra spectrum shows a clear Iron K line, indicative of a relatively high metallicity of the intra-cluster medium.

(Blakeslee et al. 2003, Fig.1)
Color composite of the core region of RDCS1252, constructed from our ACS/WFC F775W and F850LP images. The displayed  field size is roughly 1' across, or less than 4% of the full mosaic.
(See also the STScI Press Release).
A color composite of the HST/ACS (i and z bands) and deep VLT/ISAAC (J+Ks band) images, covering a field of 4 arcmin (or 2 Mpc at z=1.24) around the cluster (note: here E is up, N to the right). For intermediate, high-resolution and zoomable images check this site.

Press Releases & Highlights

Last update: Mar 20, 2007 (PR -