Planck intermediate results. VIII. Filaments between interacting clusters

About half of the baryons of the Universe are expected to be in the form of filaments of hot and low density intergalactic medium. Most of these baryons remain undetected even by the most advanced X-ray observatories which are limited in sensitivity to the diffuse low density medium. The Planck satellite has provided hundreds of detections of the hot gas in clusters of galaxies via the thermal Sunyaev-Zel'dovich (tSZ) effect and is an ideal instrument for studying extended low density media through the tSZ effect. In this paper we use the Planck data to search for signatures of a fraction of these missing baryons between pairs of galaxy clusters. Cluster pairs are good candidates for searching for the hotter and denser phase of the intergalactic medium (which is more easily observed through the SZ effect). Using an X-ray catalogue of clusters and the Planck data, we select physical pairs of clusters as candidates. Using the Planck data we construct a local map of the tSZ effect centered on each pair of galaxy clusters. ROSAT data is used to construct X-ray maps of these pairs. After having modelled and subtracted the tSZ effect and X-ray emission for each cluster in the pair we study the residuals on both the SZ and X-ray maps. For the merging cluster pair A399-A401 we observe a significant tSZ effect signal in the intercluster region beyond the virial radii of the clusters. A joint X-ray SZ analysis allows us to constrain the temperature and density of this intercluster medium. We obtain a temperature of kT = 7.1 +- 0.9, keV (consistent with previous estimates) and a baryon density of (3.7 +- 0.2)x10^-4, cm^-3. The Planck satellite mission has provided the first SZ detection of the hot and diffuse intercluster gas.

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Source ISSN: 0004-6361
Author Collaboration, Planck, Ade, P.A.R., Aghanim, N., Arnaud, M., Ashdown, M., Atrio-Barandela, F., Aumont, J., Baccigalupi, C., Balbi, A., Banday, A. J., Barreiro, R. B., Bartlett, J.G., Battaner, E., Benabed, K., Benoit, A., Bernard, J. -P., Bersanelli, M., Bhatia, R., Bikmaev, I., Böhringer, H., Bonaldi, A., Bond, J. R., Borrill, J., Bouchet, F. R., Bourdin, H., Burenin, R., Burigana, C., Cabella, P., Cardoso, J.-F., Castex, G., Catalano, A., Cayón, L., Chamballu, A., Chary, R. -R., Chiang, L. -y, Chon, G., Christensen, P. R., Clements, D. L., Colafrancesco, S., Colombo, L. P. L., Comis, B., Coulais, A., Crill, B. P., Cuttaia, F., da Silva, A., Dahle, H., Danese, L., Davis, R. J., de Bernardis, P., de Gasperis, G., de Zotti, G., Delabrouille, J., Démoclès, J., Désert, F. -X., Diego, J. M., Dolag, K., Dole, H., Donzelli, S., Doré, O., Dörl, U., Douspis, M., Dupac, X., Efstathiou, G., Ensslin, T. A., Eriksen, H. K., Finelli, F., Flores-Cacho, I., Forni, O., Frailis, M., Franceschi, E., Frommert, M., Galeotta, S., Ganga, K., Génova-Santos, R. T., Giard, M., Gilfanov, M., Giraud-Héraud, Y., González-Nuevo, J., Górski, K. M., Gregorio, A., Gruppuso, A., Hansen, F. K., Harrison, D., Hempel, A., Henrot-Versillé, S., Hernández-Monteagudo, C., Herranz, D., Hildebrandt, S. R., Hivon, E., Hobson, M., Holmes, W. A., Hovest, W., Hurier, G., Jaffe, T. R., Jaffe, A. H., Jagemann, T., Jones, W. C., Juvela, M., Khamitov, I., Kisner, T. S., Kneissl, R., Knoche, J., Knox, L., Kunz, M., Kurki-Suonio, H., Lagache, Guilaine, Lamarre, J. -M., Lasenby, A., Lawrence, C. R., Le Jeune, M., Leonardi, R., Lilje, P. B., Linden-Vørnle, M., López-Caniego, M., Lubin, P. M., Luzzi, G., Macías-Pérez, J.F., Maffei, B., Maino, D., Mandolesi, N., Maris, M., Marleau, F., Marshall, D. J., Martínez-González, E., Masi, S., Massardi, M., Matarrese, S., Matthai, F., Mazzotta, P., Mei, S., Melchiorri, A., Melin, J. -B., Mendes, L., Mennella, A., Mitra, Subhabrata, Miville-Deschênes, M. -A., Moneti, A., Montier, L., Morgante, G., Munshi, D., Murphy, J. A., Naselsky, P., Nati, F., Natoli, P., Nørgaard-Nielsen, H. U., Noviello, F., Novikov, D., Novikov, I., Osborne, S., Pajot, F., Paoletti, D., Pasian, F., Patanchon, G., Perdereau, O., Perotto, L., Perrotta, F., Piacentini, F., Piat, M., Pierpaoli, E., Piffaretti, R., Plaszczynski, Stéphane, Pointecouteau, E., Polenta, G., Ponthieu, N., Popa, L., Poutanen, T., Pratt, G. W., Prunet, S., Puget, J. -L., Rachen, J. P., Rebolo, R., Reinecke, M., Remazeilles, M., Renault, C., Ricciardi, S., Riller, T., Ristorcelli, I., Rocha, G., Roman, M., Rosset, C., Rossetti, M., Rubiño-Martín, J. A., Rusholme, B., Sandri, M., Savini, G., Schaefer, B. M., Scott, D., Smoot, G.F., Starck, Jean-Luc, Sudiwala, R., Sunyaev, R., Sutton, D., Suur-Uski, A. -S., Sygnet, J. -F., Tauber, J. A., Terenzi, L., Toffolatti, L., Tomasi, M., Tristram, M., Valenziano, L., van Tent, B., Vielva, P., Villa, Francesca, Vittorio, N., Wade, L. A., Wandelt, B. D., Welikala, N., White, S. D. M., Yvon, D., Zacchei, A., Zonca, A.
Maintainer CCSD
Last Updated May 14, 2026, 06:10 (UTC)
Created May 14, 2026, 06:10 (UTC)
Identifier in2p3-00792990
Language en
contributor APC - Cosmologie ; AstroParticule et Cosmologie (APC (UMR_7164)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris ; Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris ; Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
creator Collaboration, Planck
date 2013-02-14T00:00:00
harvest_object_id 3e995dfb-ab3e-4fb9-beba-e22eb009c249
harvest_source_id 3374d638-d20b-4672-ba96-a23232d55657
harvest_source_title test moissonnage SELUNE
metadata_modified 2026-04-23T00:00:00
relation info:eu-repo/semantics/altIdentifier/arxiv/1208.5911
set_spec type:ART