CLASH: PRECISE NEW CONSTRAINTS ON THE MASS PROFILE OF THE GALAXY CLUSTER A2261

Journal Article · Thu Sep 20 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/757/1/22· OSTI ID:22092295

Coe, Dan; Postman, Marc; Bradley, Larry; Koekemoer, Anton ^[1]; Umetsu, Keiichi ^[2]; Zitrin, Adi ^[3]; Donahue, Megan ^[4]; Medezinski, Elinor; Wei, Zheng; Lemze, Doron ^[5]; Carrasco, Mauricio; Anguita, Timo; Infante, Leopoldo ^[6]; Geller, Margaret J.; Rines, Kenneth J.; Kurtz, Michael J. ^[7]; Diaferio, Antonaldo ^[8]; Nonino, Mario ^[9]; Molino, Alberto ^[10]; Mahdavi, Andisheh ^[11] ; others, and

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1. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
2. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan (China)
3. Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie der Universitaet Heidelberg, Heidelberg (Germany)
4. Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States)
5. Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD (United States)
6. Department of Astronomy and Astrophysics, AIUC, Pontificia Universidad Catolica de Chile, Santiago (Chile)
7. Smithsonian Astrophysical Observatory, Cambridge, MA (United States)
8. Dipartimento di Fisica Generale 'Amedeo Avogadro', Universita degli Studi di Torino, Turin (Italy)
9. Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Trieste, Trieste (Italy)
10. Instituto de Astrofisica de Andalucia, Granada (Spain)
11. Department of Physics and Astronomy, San Francisco State University, San Francisco, CA (United States)

We precisely constrain the inner mass profile of A2261 (z = 0.225) for the first time and determine that this cluster is not 'overconcentrated' as found previously, implying a formation time in agreement with {Lambda}CDM expectations. These results are based on multiple strong-lensing analyses of new 16-band Hubble Space Telescope imaging obtained as part of the Cluster Lensing and Supernova survey with Hubble. Combining this with revised weak-lensing analyses of Subaru wide-field imaging with five-band Subaru + KPNO photometry, we place tight new constraints on the halo virial mass M{sub vir} = (2.2 {+-} 0.2) Multiplication-Sign 10{sup 15} M{sub Sun} h {sup -1}{sub 70} (within r{sub vir} Almost-Equal-To 3 Mpc h {sup -1}{sub 70}) and concentration c{sub vir} = 6.2 {+-} 0.3 when assuming a spherical halo. This agrees broadly with average c(M, z) predictions from recent {Lambda}CDM simulations, which span 5 {approx}< (c) {approx}< 8. Our most significant systematic uncertainty is halo elongation along the line of sight (LOS). To estimate this, we also derive a mass profile based on archival Chandra X-ray observations and find it to be {approx}35% lower than our lensing-derived profile at r{sub 2500} {approx} 600 kpc. Agreement can be achieved by a halo elongated with a {approx}2:1 axis ratio along our LOS. For this elongated halo model, we find M{sub vir} = (1.7 {+-} 0.2) Multiplication-Sign 10{sup 15} M{sub Sun} h {sup -1}{sub 70} and c{sub vir} = 4.6 {+-} 0.2, placing rough lower limits on these values. The need for halo elongation can be partially obviated by non-thermal pressure support and, perhaps entirely, by systematic errors in the X-ray mass measurements. We estimate the effect of background structures based on MMT/Hectospec spectroscopic redshifts and find that these tend to lower M{sub vir} further by {approx}7% and increase c{sub vir} by {approx}5%.

• OSTI ID: 22092295
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 757; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
COSMOLOGICAL CONSTANT
COSMOLOGICAL MODELS
COSMOLOGY
GALAXIES
GALAXY CLUSTERS
GAMMA ASTRONOMY
GRAVITATIONAL LENSES
MASS
NONLUMINOUS MATTER
PHOTOMETRY
RED SHIFT
SPACE
SUPERNOVAE
SUPPORTS
TELESCOPES
X RADIATION