Planck early results. XXVI. Detection with Planck and confirmation by XMM-Newton of PLCK G266.6-27.3, an exceptionally X-ray luminous and massive galaxy cluster at z similar to 1

TY - JOUR

T1 - Planck early results. XXVI. Detection with Planck and confirmation by XMM-Newton of PLCK G266.6-27.3, an exceptionally X-ray luminous and massive galaxy cluster at z similar to 1

AU - Aghanim...[et al.], N.

AU - Arnaud, M.

AU - Ashdown, W.

AU - Christensen, Per Rex

AU - Nasselski, Pavel

PY - 2011/12/1

Y1 - 2011/12/1

N2 - We present first results on PLCKG266.6-27.3, a galaxy cluster candidate detected at a signal-to-noise ratio of 5 in the Planck All Sky survey. An XMM-Newton validation observation has allowed us to confirm that the candidate isa bona fide galaxy cluster. With these X-ray data we measure an accurate redshift, z = 0.94 ± 0.02, and estimate the cluster mass to be M 500 = (7.8 ± 0.8) × 1014 M. PLCKG266.6-27.3 is an exceptional system: its luminosity of LX [0.5-2.0 keV] = (1.4 ± 0.05) × 1045 erg s-1 equals that of the two most luminous known clusters in the z > 0.5 universe, and it is one of the most massive clusters at z ~ 1. Moreover, unlike the majority of high-redshift clusters, PLCKG266.6-27.3 appears to be highly relaxed. This observation confirms Planck's capability of detecting high-redshift, high-mass clusters, and opens the way to the systematic study of population evolution in the exponential tail of the mass function.

AB - We present first results on PLCKG266.6-27.3, a galaxy cluster candidate detected at a signal-to-noise ratio of 5 in the Planck All Sky survey. An XMM-Newton validation observation has allowed us to confirm that the candidate isa bona fide galaxy cluster. With these X-ray data we measure an accurate redshift, z = 0.94 ± 0.02, and estimate the cluster mass to be M 500 = (7.8 ± 0.8) × 1014 M. PLCKG266.6-27.3 is an exceptional system: its luminosity of LX [0.5-2.0 keV] = (1.4 ± 0.05) × 1045 erg s-1 equals that of the two most luminous known clusters in the z > 0.5 universe, and it is one of the most massive clusters at z ~ 1. Moreover, unlike the majority of high-redshift clusters, PLCKG266.6-27.3 appears to be highly relaxed. This observation confirms Planck's capability of detecting high-redshift, high-mass clusters, and opens the way to the systematic study of population evolution in the exponential tail of the mass function.

U2 - 10.1051/0004-6361/201117430

DO - 10.1051/0004-6361/201117430

M3 - Journal article

SN - 0004-6361

VL - 536

SP - A26

JO - Astronomy and Astrophysics Supplement Series

JF - Astronomy and Astrophysics Supplement Series

ER -