The Astrophysical Journal

The Astrophysical Journal

Quick search Find article
Quick search
Find article
The Astrophysical Journal Volume 663 Number 1 Create an alert RSS this journal

R. Demarco et al. 2007 ApJ 663 164 doi:10.1086/518117

VLT and ACS Observations of RDCS J1252.9–2927: Dynamical Structure and Galaxy Populations in a Massive Cluster at z = 1.237*

FREE ISSUE

R. Demarco1, P. Rosati2, C. Lidman3, M. Girardi4, M. Nonino5, A. Rettura1, V. Strazzullo2, A. van der Wel1, H. C. Ford1, V. Mainieri2, B. P. Holden6, S. A. Stanford7, J. P. Blakeslee8, R. Gobat2, M. Postman9, P. Tozzi5,10, R. A. Overzier1, A. W. Zirm1, N. Benítez11, N. L. Homeier1, G. D. Illingworth6, L. Infante12, M. J. Jee1, S. Mei13,14, F. Menanteau15, V. Motta16, W. Zheng1, M. Clampin17 and G. Hartig9

Show affiliations

Tag this article Full text PDF (703 KB) HTML with Enhancements

Abstract References Cited By

We present results from an extensive spectroscopic survey, carried out with VLT FORS, and from an extensive multiwavelength imaging data set from the HST Advanced Camera for Surveys and ground-based facilities, of the cluster of galaxies RDCS J1252.9-2927. We have spectroscopically confirmed 38 cluster members in the redshift range 1.22 < z < 1.25. A cluster median redshift of z = 1.237 and a rest-frame velocity dispersion of 747img1.gif km s-1 are obtained. Using the 38 confirmed redshifts, we were able to resolve, for the first time at z > 1, kinematic structure. The velocity distribution, which is not Gaussian at the 95% confidence level, is consistent with two groups that are also responsible for the projected east-west elongation of the cluster. The groups are composed of 26 and 12 galaxies with velocity dispersions of 486img2.gif and 426img3.gif km s-1, respectively. The elongation is also seen in the intracluster gas and the dark matter distribution. This leads us to conclude that RDCS J1252.9-2927 has not yet reached a final virial state. We extend the analysis of the color-magnitude diagram of spectroscopic members to more than 1 Mpc from the cluster center. The scatter and slope of non-[O II]-emitting cluster members in the near-IR red sequence is similar to that seen in clusters at lower redshift. Furthermore, most of the galaxies with luminosities greater than ~Kimg4.gif + 1.5 do not show any [O II], indicating that these more luminous, redder galaxies have stopped forming stars earlier than the fainter, bluer galaxies. Our observations provide detailed dynamical and spectrophotometric information on galaxies in this exceptional high-redshift cluster, delivering an in-depth view of structure formation at this epoch only 5 Gyr after the big bang.


Footnote
*  Based on observations carried out with the ESO VLT under programs 166.A-0701, 69.A-0683, 73.A-0832, and 76.A-0889.
Subject headings

galaxies: clusters: general; galaxies: clusters: individual (ClG J1252.9–2927)


Dates

Issue 1 (2007 July 1)

Received 2006 December 8, accepted for publication 2007 March 5



Your last 10 viewed
  1. VLT and ACS Observations of RDCS J1252.9–2927: Dynamical Structure and Galaxy Populations in a Massive Cluster at z = 1.237

    R. Demarco et al. 2007 ApJ 663 164

  2. Anomalous electron trapping by localized magnetic fields

    F Bentosela et al 1999 J. Phys. A: Math. Gen. 32 3029

  3. The dependence of filtered vacuum arc deposited ZnO–SnO2 thin films characteristics on substrate temperature

    E Çetinórgü et al 2006 J. Phys. D: Appl. Phys. 39 5245

  4. Dispersion of electromagnetic waves in stratified and nonstationary media (exactly solvable models)

    Aleksandr B Shvartsburg 2000 Phys.-Usp. 43 1201

  5. An approach for the fabrication of hexagonally ordered arrays of cylindrical nanoholes in crystalline and amorphous silicon based on the self-organization of polymer micelles

    Sabrina Brieger et al 2006 Nanotechnology 17 4991

  6. Elliptic flow from a hybrid CGC, full 3D hydro and hadronic cascade model

    T Hirano et al 2007 J. Phys. G: Nucl. Part. Phys. 34 S879

  7. Quantum helicity entropy of moving bodies

    Song He et al 2007 J. Phys. A: Math. Theor. 40 F857

  8. Calculation of SAR and temperature rise in a high-resolution vascularized model of the human eye and orbit when exposed to a dipole antenna at 900, 1500 and 1800 MHz

    V M M Flyckt et al 2007 Phys. Med. Biol. 52 2691

  9. Hyperelliptic reduction of the Benney moment equations

    Sadie Baldwin and John Gibbons 2003 J. Phys. A: Math. Gen. 36 8393

  10. Investigating surface magnetism by means of photoexcitation electron emission microscopy

    Claus M Schneider and Gerd Schönhense 2002 Rep. Prog. Phys. 65 1785

Users also read

What's this?
This innovative new feature generates a list of articles 'also read' by other users based on them reading the original article. Article abstracts citations and references are all considered and weighted accordingly. We hope that this will help you find relevant papers for your research.

  1. Evolution of the Color-Magnitude Relation in Galaxy Clusters at z ~ 1 from the ACS Intermediate Redshift Cluster Survey
  2. Chandra and XMM-Newton Observations of RDCS 1252.9−2927, a Massive Cluster at z = 1.24
  3. Star Formation Histories in a Cluster Environment at z ~ 0.84
More

Share

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.