skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: CHANDRA DEEP OBSERVATION OF XDCP J0044.0-2033, A MASSIVE GALAXY CLUSTER AT z > 1.5

Abstract

We report the analysis of the Chandra observation of XDCP J0044.0-2033, a massive, distant (z = 1.579) galaxy cluster discovered in the XDCP survey. The total exposure time of 380 ks with Chandra ACIS-S provides the deepest X-ray observation currently achieved on a massive, high-redshift cluster. Extended emission from the intra cluster medium (ICM) is detected at a very high significance level (S/N ∼ 20) on a circular region with a 44'' radius, corresponding to R {sub ext} = 375 kpc at the cluster redshift. We perform an X-ray spectral fit of the ICM emission modeling the spectrum with a single-temperature thermal mekal model. Our analysis provides a global temperature kT=6.7{sub −0.9}{sup +1.3} keV, and a iron abundance Z{sub Fe}=0.41{sub −0.26}{sup +0.29}Z{sub Fe{sub ⊙}} (error bars correspond to 1σ). We fit the background-subtracted surface brightness profile with a single β-model out to 44'', finding a rather flat profile with no hints of a cool core. We derive the deprojected electron density profile and compute the ICM mass within the extraction radius R {sub ext} = 375 kpc to be M {sub ICM}(r < R {sub ext}) = (1.48 ± 0.20) × 10{sup 13} M {sub ☉}. Under the assumption of hydrostatic equilibrium and assumingmore » isothermality within R {sub ext}, the total mass is M{sub 2500}=1.23{sub −0.27}{sup +0.46}×10{sup 14} M{sub ⊙} for R{sub 2500}=240{sub −20}{sup +30} kpc. Extrapolating the profile at radii larger than the extraction radius R {sub ext} we find M{sub 500}=3.2{sub −0.6}{sup +0.9}×10{sup 14} M{sub ⊙} for R{sub 500}=562{sub −37}{sup +50} kpc. This analysis establishes the existence of virialized, massive galaxy clusters at redshift z ∼ 1.6, paving the way to the investigation of the progenitors of the most massive clusters today. Given its mass and the XDCP survey volume, XDCP J0044.0-2033 does not create significant tension with the WMAP-7 ΛCDM cosmology.« less

Authors:
; ;  [1];  [2];  [3];  [4]; ;  [5]; ;  [6];  [7];  [8];  [9];  [10]
  1. INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)
  2. Department of Physics, University of California, Davis One Shields Avenue, Davis, CA 95616-8677 (United States)
  3. INAF-Osservatorio Astronomico di Roma (OAR), via Frascati 33, I-00040 Monte Porzio Catone (Italy)
  4. Istitut d'Astrophysique Spatiale, CNRS, Bat. 121, Université Paris-Sud, F-91405 Orsay (France)
  5. Harvard-Smithsonian Center for Astrophysics 60 Garden Street, Cambridge, MA 02138 (United States)
  6. Università degli Studi di Trieste, Dipartimento di Fisica, Via A.Valerio, 2 I-34127 Trieste (Italy)
  7. Max-Planck-Institut fr extraterrestrische Physik Giessenbachstr.1, D-85748 Garching (Germany)
  8. European Space Astronomy Centre (ESAC), European Space Agency, Apartado de Correos 78, E-28691 Villanueva de la Canada, Madrid (Spain)
  9. CEA Saclay, Service d'Astrophysique, LOrme des Merisiers, Bat. 709, F-91191 Gif-sur-Yvette Cedex (France)
  10. INAF-Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34143 Trieste (Italy)
Publication Date:
OSTI Identifier:
22364453
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 799; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BRIGHTNESS; COMPUTERIZED SIMULATION; COSMOLOGICAL CONSTANT; COSMOLOGY; ELECTRON DENSITY; EQUILIBRIUM; GALAXY CLUSTERS; IRON; KEV RANGE; MASS; RED SHIFT; UNIVERSE; X RADIATION; X-RAY GALAXIES

Citation Formats

Tozzi, P., Santos, J. S., Rosati, P., Jee, M. J., Fassbender, R., Nastasi, A., Forman, W., Jones, C., Sartoris, B., Borgani, S., Boehringer, H., Altieri, B., Pratt, G. W., and Nonino, M. CHANDRA DEEP OBSERVATION OF XDCP J0044.0-2033, A MASSIVE GALAXY CLUSTER AT z > 1.5. United States: N. p., 2015. Web. doi:10.1088/0004-637X/799/1/93.
Tozzi, P., Santos, J. S., Rosati, P., Jee, M. J., Fassbender, R., Nastasi, A., Forman, W., Jones, C., Sartoris, B., Borgani, S., Boehringer, H., Altieri, B., Pratt, G. W., & Nonino, M. CHANDRA DEEP OBSERVATION OF XDCP J0044.0-2033, A MASSIVE GALAXY CLUSTER AT z > 1.5. United States. doi:10.1088/0004-637X/799/1/93.
Tozzi, P., Santos, J. S., Rosati, P., Jee, M. J., Fassbender, R., Nastasi, A., Forman, W., Jones, C., Sartoris, B., Borgani, S., Boehringer, H., Altieri, B., Pratt, G. W., and Nonino, M. Tue . "CHANDRA DEEP OBSERVATION OF XDCP J0044.0-2033, A MASSIVE GALAXY CLUSTER AT z > 1.5". United States. doi:10.1088/0004-637X/799/1/93.
@article{osti_22364453,
title = {CHANDRA DEEP OBSERVATION OF XDCP J0044.0-2033, A MASSIVE GALAXY CLUSTER AT z > 1.5},
author = {Tozzi, P. and Santos, J. S. and Rosati, P. and Jee, M. J. and Fassbender, R. and Nastasi, A. and Forman, W. and Jones, C. and Sartoris, B. and Borgani, S. and Boehringer, H. and Altieri, B. and Pratt, G. W. and Nonino, M.},
abstractNote = {We report the analysis of the Chandra observation of XDCP J0044.0-2033, a massive, distant (z = 1.579) galaxy cluster discovered in the XDCP survey. The total exposure time of 380 ks with Chandra ACIS-S provides the deepest X-ray observation currently achieved on a massive, high-redshift cluster. Extended emission from the intra cluster medium (ICM) is detected at a very high significance level (S/N ∼ 20) on a circular region with a 44'' radius, corresponding to R {sub ext} = 375 kpc at the cluster redshift. We perform an X-ray spectral fit of the ICM emission modeling the spectrum with a single-temperature thermal mekal model. Our analysis provides a global temperature kT=6.7{sub −0.9}{sup +1.3} keV, and a iron abundance Z{sub Fe}=0.41{sub −0.26}{sup +0.29}Z{sub Fe{sub ⊙}} (error bars correspond to 1σ). We fit the background-subtracted surface brightness profile with a single β-model out to 44'', finding a rather flat profile with no hints of a cool core. We derive the deprojected electron density profile and compute the ICM mass within the extraction radius R {sub ext} = 375 kpc to be M {sub ICM}(r < R {sub ext}) = (1.48 ± 0.20) × 10{sup 13} M {sub ☉}. Under the assumption of hydrostatic equilibrium and assuming isothermality within R {sub ext}, the total mass is M{sub 2500}=1.23{sub −0.27}{sup +0.46}×10{sup 14} M{sub ⊙} for R{sub 2500}=240{sub −20}{sup +30} kpc. Extrapolating the profile at radii larger than the extraction radius R {sub ext} we find M{sub 500}=3.2{sub −0.6}{sup +0.9}×10{sup 14} M{sub ⊙} for R{sub 500}=562{sub −37}{sup +50} kpc. This analysis establishes the existence of virialized, massive galaxy clusters at redshift z ∼ 1.6, paving the way to the investigation of the progenitors of the most massive clusters today. Given its mass and the XDCP survey volume, XDCP J0044.0-2033 does not create significant tension with the WMAP-7 ΛCDM cosmology.},
doi = {10.1088/0004-637X/799/1/93},
journal = {Astrophysical Journal},
number = 1,
volume = 799,
place = {United States},
year = {Tue Jan 20 00:00:00 EST 2015},
month = {Tue Jan 20 00:00:00 EST 2015}
}