We present the XMM-Newton follow-up for confirmation of Planck cluster candidates. Twenty-five candidates have been observed to date using snapshot (similar to 10 ks) exposures, ten as part of a pilot programme to sample a low range of signal-to-noise ratios (4 < S/N < 6), and a further 15 in a programme to observe a sample of S/N > 5 candidates. The sensitivity and spatial resolution of XMM-Newton allows unambiguous discrimination between clusters and false candidates. The 4 false candidates have S/N <= 4.1. A total of 21 candidates are confirmed as extended X-ray sources. Seventeen are single clusters, the majority of which are found to have highly irregular and disturbed morphologies (about similar to 70%). The remaining four sources are multiple systems, including the unexpected discovery of a supercluster at z = 0.45. For 20 sources we are able to derive a redshift estimate from the X-ray Fe K line (albeit of variable quality). The new clusters span the redshift range 0.09 less than or similar to z less than or similar to 0.54, with a median redshift of z similar to 0.37. A first determination is made of their X-ray properties including the characteristic size, which is used to improve the estimate of the SZ Compton parameter, Y-500. The follow-up validation programme has helped to optimise the Planck candidate selection process. It has also provided a preview of the X-ray properties of these newly-discovered clusters, allowing comparison with their SZ properties, and to the X-ray and SZ properties of known clusters observed in the Planck survey. Our results suggest that Planck may have started to reveal a non-negligible population of massive dynamically perturbed objects that is under-represented in X-ray surveys. However, despite their particular properties, these new clusters appear to follow the Y-500-Y-X relation established for X-ray selected objects, where Y-X is the product of the gas mass and temperature.
Planck early results. IX. XMM-Newton follow-up for validation of Planck cluster candidates / Planck, Collaboration; N., Aghanim; M., Arnaud; M., Ashdown; J., Aumont; C., Baccigalupi; A., Balbi; A. J., Banday; R. B., Barreiro; M., Bartelmann; J. G., Bartlett; E., Battaner; K., Benabed; A., Benoit; J. P., Bernard; M., Bersanelli; R., Bhatia; J. J., Bock; A., Bonaldi; J. R., Bond; J., Borrill; F. R., Bouchet; M. L., Brown; M., Bucher; C., Burigana; Cabella, Paolo; C. M., Cantalupo; J. F., Cardoso; P., Carvalho; Catalano, Andrea; L., Cayon; A., Challinor; A., Chamballu; L. Y., Chiang; G., Chon; P. R., Christensen; E., Churazov; D. L., Clements; S., Colafrancesco; S., Colombi; F., Couchot; A., Coulais; B. P., Crill; F., Cuttaia; A., Da Silva; H., Dahle; L., Danese; DE BERNARDIS, Paolo; G., De Gasperis; A., De Rosa; G., De Zotti; J., Delabrouille; J. M., Delouis; F. X., Desert; J. M., Diego; K., Dolag; S., Donzelli; O., Dore; U., Dorl; M., Douspis; X., Dupac; G., Efstathiou; T. A., Ensslin; F., Finelli; I., Flores Cacho; O., Forni; M., Frailis; E., Franceschi; S., Fromenteau; S., Galeotta; K., Ganga; R. T., Genova Santos; M., Giard; G., Giardino; Y., Giraud Heraud; J., Gonzalez Nuevo; R., Gonzalez Riestra; K. M., Gorski; S., Gratton; A., Gregorio; A., Gruppuso; D., Harrison; P., Heinamaki; S., Henrot Versille; C., Hernandez Monteagudo; D., Herranz; S. R., Hildebrandt; E., Hivon; M., Hobson; W. A., Holmes; W., Hovest; R. J., Hoyland; K. M., Huffenberger; G., Hurier; A. H., Jaffe; M., Juvela; E., Keihanen; R., Keskitalo; T. S., Kisner; R., Kneissl; L., Knox; H., Kurki Suonio; G., Lagache; J. M., Lamarre; A., Lasenby; R. J., Laureijs; C. R., Lawrence; M., Le Jeune; S., Leach; R., Leonardi; A., Liddle; M., Linden Vørnle; M., Linden Vornle; M., Lopez Caniego; P. M., Lubin; J. F., Macias Perez; B., Maffei; D., Maino; N., Mandolesi; R., Mann; M., Maris; F., Marleau; E., Martinez Gonzalez; Masi, Silvia; S., Matarrese; F., Matthai; P., Mazzotta; Melchiorri, Alessandro; J. B., Melin; L., Mendes; A., Mennella; S., Mitra; M. A., Miville Deschenes; A., Moneti; L., Montier; G., Morgante; D., Mortlock; D., Munshi; A., Murphy; P., Naselsky; P., Natoli; C. B., Netterfield; H. U., Nørgaard Nielsen; H. U., Norgaard Nielsen; F., Noviello; D., Novikov; I., Novikov; S., Osborne; F., Pajot; F., Pasian; G., Patanchon; O., Perdereau; L., Perotto; F., Perrotta; Piacentini, Francesco; M., Piat; E., Pierpaoli; R., Piffaretti; S., Plaszczynski; E., Pointecouteau; Polenta, Gianluca; N., Ponthieu; T., Poutanen; G. W., Pratt; G., Prezeau; S., Prunet; J. L., Puget; R., Rebolo; M., Reinecke; C., Renault; Ricciardi, Sara; T., Riller; I., Ristorcelli; G., Rocha; C., Rosset; J. A., Rubino Martin; B., Rusholme; E., Saar; M., Sandri; D., Santos; B. M., Schaefer; D., Scott; M. D., Seiffert; G. F., Smoot; J. L., Starck; Stivoli, Federico; V., Stolyarov; R., Sunyaev; J. F., Sygnet; J. A., Tauber; L., Terenzi; L., Toffolatti; M., Tomasi; J. P., Torre; M., Tristram; J., Tuovinen; L., Valenziano; L., Vibert; P., Vielva; F., Villa; N., Vittorio; B. D., Wandelt; S. D. M., White; D., Yvon; A., Zacchei; A., Zonca. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - STAMPA. - 536:(2011), p. A9. [10.1051/0004-6361/201116460]
Planck early results. IX. XMM-Newton follow-up for validation of Planck cluster candidates
CABELLA, PAOLO;CATALANO, Andrea;DE BERNARDIS, Paolo;G. De Gasperis;MASI, Silvia;MELCHIORRI, Alessandro;PIACENTINI, Francesco;POLENTA, GIANLUCA;RICCIARDI, Sara;STIVOLI, federico;
2011
Abstract
We present the XMM-Newton follow-up for confirmation of Planck cluster candidates. Twenty-five candidates have been observed to date using snapshot (similar to 10 ks) exposures, ten as part of a pilot programme to sample a low range of signal-to-noise ratios (4 < S/N < 6), and a further 15 in a programme to observe a sample of S/N > 5 candidates. The sensitivity and spatial resolution of XMM-Newton allows unambiguous discrimination between clusters and false candidates. The 4 false candidates have S/N <= 4.1. A total of 21 candidates are confirmed as extended X-ray sources. Seventeen are single clusters, the majority of which are found to have highly irregular and disturbed morphologies (about similar to 70%). The remaining four sources are multiple systems, including the unexpected discovery of a supercluster at z = 0.45. For 20 sources we are able to derive a redshift estimate from the X-ray Fe K line (albeit of variable quality). The new clusters span the redshift range 0.09 less than or similar to z less than or similar to 0.54, with a median redshift of z similar to 0.37. A first determination is made of their X-ray properties including the characteristic size, which is used to improve the estimate of the SZ Compton parameter, Y-500. The follow-up validation programme has helped to optimise the Planck candidate selection process. It has also provided a preview of the X-ray properties of these newly-discovered clusters, allowing comparison with their SZ properties, and to the X-ray and SZ properties of known clusters observed in the Planck survey. Our results suggest that Planck may have started to reveal a non-negligible population of massive dynamically perturbed objects that is under-represented in X-ray surveys. However, despite their particular properties, these new clusters appear to follow the Y-500-Y-X relation established for X-ray selected objects, where Y-X is the product of the gas mass and temperature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
