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The atacama cosmology telescope: act-cl j0102-4915 'el gordo', a massive merging cluster at redshift 0.87
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Nolta, Michael R. Gonzalez, Jorge Moodley, Kavilan Reese, Erik D. Hincks, Adam D. Infante, Leopoldo Spergel, David N. Sehgal, Neelima Menanteau, Felipe Niemack, Michael D. Sifon, Cristobal Kosowsky, Arthur Wollack, Edward Das, Sudeep Marsden, Danica Marriage, Tobias A. Dunkley, Joanna Hajian, Amir Barrientos, L. Felipe Devlin, Mark J. Page, Lyman A. Baker, Andrew J. Bond, John R. Staggs, Suzanne T. Hughes, John P. Seivers, Jon Hilton, Matt |
| Copyright Year | 2012 |
| Description | We present a detailed analysis from new multi-wavelength observations of the exceptional galaxy cluster ACT-CL J0102â4915, likely the most massive, hottest, most X-ray luminous and brightest Sunyaev-Zel'dovich (SZ) effect cluster known at redshifts greater than 0.6. The Atacama Cosmology Telescope (ACT) collaboration discovered ACT-CL J0102â4915 as the most significant Sunyaev-Zeldovich (SZ) decrement in a sky survey area of 755 square degrees. Our VLT/FORS2 spectra of 89 member galaxies yield a cluster redshift, z = 0.870, and velocity dispersion, sigma(sub gal) = 1321+/-106 km sâ1. Our Chandra observations reveal a hot and X-ray luminous system with an integrated temperature of T(sub X) = 14.5+/-1.0 keV and 0.5-2.0 keV band luminosity of L(sub X) = (2.19+/-0.11)Ã10(sup 45) h(sup â2)(sub 70) erg sâ1. We obtain several statistically consistent cluster mass estimates; using empirical mass scaling relations with velocity dispersion, X-ray Y(sub X), and integrated SZ distortion, we estimate a cluster mass of M(sub 200a) = (2.16+/-0.32)Ã1015 h(sup â1)(sub 70) solar mass. We constrain the stellar content of the cluster to be less than 1% of the total mass, using Spitzer IRAC and optical imaging. The Chandra and VLT/FORS2 optical data also reveal that ACT-CL J0102â4915 is undergoing a major merger between components with a mass ratio of approximately 2 to 1. The X-ray data show significant temperature variations from a low of 6.6+/-0.7 keV at the merging low-entropy, high-metallicity, cool core to a high of 22+/-6 keV. We also see a wake in the X-ray surface brightness and deprojected gas density caused by the passage of one cluster through the other. Archival radio data at 843 MHz reveal diffuse radio emission that, if associated with the cluster, indicates the presence of an intense double radio relic, hosted by the highest redshift cluster yet. ACT-CL J0102â4915 is possibly a high-redshift analog of the famous Bullet Cluster. Such a massive cluster at this redshift is rare, although consistent with the standard ÎCDM cosmology in the lower part of its allowed mass range. Massive, highredshift mergers like ACT-CL J0102â4915 are unlikely to be reproduced in the current generation of numerical N-body cosmological simulations. |
| File Size | 919785 |
| Page Count | 18 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20140005999 |
| Archival Resource Key | ark:/13960/t75t8mz8f |
| Language | English |
| Publisher Date | 2012-01-04 |
| Access Restriction | Open |
| Subject Keyword | Cosmology Observations Galaxy Clusters Cosmic Background Radiation Galactic Clusters Red Shift Sunyaev-zeldovich Effect Dark Matter Stellar Mass Telescopes Imaging Techniques Cosmology Sky Surveys Astronomy Mass Ratios Many Body Problem Stellar Luminosity Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
