Planck intermediate results I. Further validation of new Planck clusters with XMM-Newton

TY - JOUR

T1 - Planck intermediate results I. Further validation of new Planck clusters with XMM-Newton

AU - Aghanim, N.

AU - Arnaud, M.

AU - Ashdown, M.

AU - Atrio-Barandela, F.

AU - Hornstrup, Allan

AU - Atrio-Barandela, F.

AU - Aumont, J.

AU - Baccigalupi, C.

AU - Balbi, A.

AU - Christensen, Per Rex

AU - Banday, A.J.

AU - Nasselski, Pavel

PY - 2012/7/5

Y1 - 2012/7/5

N2 - We present further results from the ongoing XMM-Newton validation follow-up of Planck cluster candidates, detailing X-ray observations of eleven candidates detected at a signal-to-noise ratio of 4.5 < S/N < 5.3 in the same 10-month survey maps used in the construction of the Early SZ sample. The sample was selected in order to test internal SZ quality flags, and the pertinence of these flags is discussed in light of the validation results. Ten of the candidates are found to be bona fide clusters lying below the RASS flux limit. Redshift estimates are available for all confirmed systems via X-ray Fe-line spectroscopy. They lie in the redshift range 0.19 < z < 0.94, demonstrating Planck's capability to detect clusters up to high z. The X-ray properties of the new clusters appear to be similar to previous new detections by Planck at lower z and higher SZ flux: the majority are X-ray underluminous for their mass, estimated using Y X as mass proxy, and many have a disturbed morphology. We find tentative indication for Malmquist bias in the Y SZ-Y X relation, with a turnover at Y SZ ~ 4 × 10 -4 arcmin 2. We present additional new optical redshift determinations with ENO and ESO telescopes of candidates previously confirmed with XMM-Newton. The X-ray and optical redshifts for a total of 20 clusters are found to be in excellent agreement. We also show that useful lower limits can be put on cluster redshifts using X-ray data only via the use of the Y X vs. Y SZ and X-ray flux F X vs. Y SZ relations.

AB - We present further results from the ongoing XMM-Newton validation follow-up of Planck cluster candidates, detailing X-ray observations of eleven candidates detected at a signal-to-noise ratio of 4.5 < S/N < 5.3 in the same 10-month survey maps used in the construction of the Early SZ sample. The sample was selected in order to test internal SZ quality flags, and the pertinence of these flags is discussed in light of the validation results. Ten of the candidates are found to be bona fide clusters lying below the RASS flux limit. Redshift estimates are available for all confirmed systems via X-ray Fe-line spectroscopy. They lie in the redshift range 0.19 < z < 0.94, demonstrating Planck's capability to detect clusters up to high z. The X-ray properties of the new clusters appear to be similar to previous new detections by Planck at lower z and higher SZ flux: the majority are X-ray underluminous for their mass, estimated using Y X as mass proxy, and many have a disturbed morphology. We find tentative indication for Malmquist bias in the Y SZ-Y X relation, with a turnover at Y SZ ~ 4 × 10 -4 arcmin 2. We present additional new optical redshift determinations with ENO and ESO telescopes of candidates previously confirmed with XMM-Newton. The X-ray and optical redshifts for a total of 20 clusters are found to be in excellent agreement. We also show that useful lower limits can be put on cluster redshifts using X-ray data only via the use of the Y X vs. Y SZ and X-ray flux F X vs. Y SZ relations.

M3 - Journal article

SN - 0004-6361

VL - 543

SP - A102

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

ER -